95 Citations
Prophages dormant bacteriophage genomes integrated within the bacterial chromosome play pivotal roles in shaping microbial communities when awakened Our current understanding of prophage activation is largely shaped by a narrow set of traditional DNA-damaging inducers such as mitomycin C and ciprofloxacin which trigger the bacterial SOS response This study employed high-throughput screening of compounds to identify novel prophage inducers using model lambdoid prophage HK We identified multiple new inducers across diverse pharmacological classes including dietary supplements and therapeutics Despite the variety in compounds all acted through SOS-dependent pathways However bleomycin an antineoplastic antibiotic demonstrated broad-spectrum and potent prophage induction exceeding ... More
Prophages, dormant bacteriophage genomes integrated within the bacterial chromosome, play pivotal roles in shaping microbial communities when awakened. Our current understanding of prophage activation is largely shaped by a narrow set of traditional DNA-damaging inducers, such as mitomycin C and ciprofloxacin, which trigger the bacterial SOS response. This study employed high-throughput screening of 3,921 compounds to identify novel prophage inducers using model lambdoid prophage HK97. We identified multiple new inducers across diverse pharmacological classes, including dietary supplements and therapeutics. Despite the variety in compounds, all acted through SOS-dependent pathways. However, bleomycin, an antineoplastic antibiotic, demonstrated broad-spectrum and potent prophage induction exceeding standard inducers, with activity validated across multiple phage-host pairings. These findings expand the repertoire of prophage inducers into commonly ingested xenobiotics and introduce bleomycin as a powerful, cost-effective tool for prophage research.
Around 75% of bacteria carry within them dormant viruses (prophages), which can awaken when the bacterium is stressed, killing the bacterium. Historically, this has been done using DNA-damaging antibiotics, but increasingly, more such signals have been discovered. Here, through a high-throughput screen, we identify phage-waking activity in several commonly consumed compounds, such as the SSRI Prozac, as well as a new DNA-damaging agent that is much more effective in waking phages than the previous gold standard. Less
Around 75% of bacteria carry within them dormant viruses (prophages), which can awaken when the bacterium is stressed, killing the bacterium. Historically, this has been done using DNA-damaging antibiotics, but increasingly, more such signals have been discovered. Here, through a high-throughput screen, we identify phage-waking activity in several commonly consumed compounds, such as the SSRI Prozac, as well as a new DNA-damaging agent that is much more effective in waking phages than the previous gold standard. Less
ADP-ribosylation is an enzymatic process where an ADP-ribose moiety is transferred from NAD to an acceptor molecule While ADP-ribosylation is well-established as a post-translational modification of proteins rifamycin antibiotics are its only known small-molecule targets ADP-ribosylation of rifampicin was first identified in Mycolicibacterium smegmatis whose Arr enzyme transfers the ADP-ribose moiety to the -hydroxy group of rifampicin preventing its interaction with the bacterial RNA polymerase thereby inactivating the antibiotic Arr homologues are widely spread among bacterial species and present in several pathogenic species often associated with mobile genetic elements Inhibition of Arr enzymes offers a promising strategy to overcome ADP-ribosylation ... More
ADP-ribosylation is an enzymatic process where an ADP-ribose moiety is transferred from NAD+ to an acceptor molecule. While ADP-ribosylation is well-established as a post-translational modification of proteins, rifamycin antibiotics are its only known small-molecule targets. ADP-ribosylation of rifampicin was first identified in Mycolicibacterium smegmatis, whose Arr enzyme transfers the ADP-ribose moiety to the 23-hydroxy group of rifampicin preventing its interaction with the bacterial RNA polymerase thereby inactivating the antibiotic. Arr homologues are widely spread among bacterial species and present in several pathogenic species often associated with mobile genetic elements. Inhibition of Arr enzymes offers a promising strategy to overcome ADP-ribosylation mediated rifamycin resistance. We developed a high-throughput activity assay, which was applied to screen an in-house library of human ADP-ribosyltransferase-targeted compounds. We identified 15 inhibitors with IC50 values below 5 µM against four Arr enzymes from M. smegmatis, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Mycobacteroides abscessus. The observed overall selectivity of the hit compounds over the other homologues indicated structural differences between the proteins. We crystallized M. smegmatis and P. aeruginosa Arr enzymes, the former in complex with its most potent hit compound with an IC50 value of 1.3 µM. We observed structural differences in the NAD+ binding pockets of the two Arr homologues explaining the selectivity. Although the Arr inhibitors did not sensitize M. smegmatis to rifampicin in a growth inhibition assay, the structural information and the collection of inhibitors provide a foundation for rational modifications and further development of the compounds. Less
Microbial production of target molecules has advanced significantly in recent years driven by innovations in enzyme engineering DNA synthesis and genomic editing However to access the massive potential of microbial production a vast parametric space remains to be investigated to optimize these biobased processes for a robust bioeconomy Here we review the current state of the art some key challenges and possible solutions We see a critical role of automation high-throughput technologies self-driving and cloud labs and data management to enable Artificial Intelligence Machine Learning and mechanistic models to overcome the design space challenges and accelerate the development of novel ... More
Microbial production of target molecules has advanced significantly in recent years driven by innovations in enzyme engineering, DNA synthesis, and genomic editing. However, to access the massive potential of microbial production, a vast parametric space remains to be investigated to optimize these biobased processes for a robust bioeconomy. Here, we review the current state of the art, some key challenges and possible solutions. We see a critical role of automation, high-throughput technologies, self-driving and cloud labs, and data management to enable Artificial Intelligence/Machine Learning and mechanistic models to overcome the design space challenges and accelerate the development of novel bio-based solutions. Accurate models will expedite the development and scale-up of engineered microbes for a range of final products from many starting materials. Less
Physical activity improves health yet the molecular mechanisms remain partially understood This study presents a high-resolution time-resolved atlas profiling proteins across plasma saliva and urine from healthy adults post-acute exercise Exercise regulated over proteins revealing distinct fluid-specific temporal dynamics By integrating fluid-specific exercise signatures with tissue and disease atlases we delineated the contribution of tissues and associations to various diseases Network analysis across body fluids elucidated coordinated remodeling in the extracellular matrix and immune activation orchestrating exercise-induced networks Many exercise-responsive plasma proteins were robust across age sex and exercise modalities indicating a conserved systemic signature Integration with genetic data established ... More
Physical activity improves health, yet the molecular mechanisms remain partially understood.
This study presents a high-resolution, time-resolved atlas profiling 10,127 proteins across
plasma, saliva, and urine from healthy adults post-acute exercise. Exercise regulated over
3,000 proteins, revealing distinct, fluid-specific temporal dynamics. By integrating fluid-specific
exercise signatures with tissue and disease atlases, we delineated the contribution of tissues
and associations to various diseases. Network analysis across body fluids elucidated
coordinated remodeling in the extracellular matrix and immune activation orchestrating
exercise-induced networks. Many exercise-responsive plasma proteins were robust across
age, sex, and exercise modalities, indicating a conserved systemic signature. Integration with
genetic data established exercise-regulated proteins as modulators of metabolic traits and
identified over 200 targeted by approved drugs, highlighting their impact on disease-relevant
pathways. This comprehensive atlas, available as an open-access resource
https://cbmr.ku.dk/research/research-groups/deshmukh-group/shiny-apps/, advances our
molecular insight into exercise adaptations and enables exerkine discovery, biomarker
development, and pharmacological exercise-mimetic strategies. Less
This study presents a high-resolution, time-resolved atlas profiling 10,127 proteins across
plasma, saliva, and urine from healthy adults post-acute exercise. Exercise regulated over
3,000 proteins, revealing distinct, fluid-specific temporal dynamics. By integrating fluid-specific
exercise signatures with tissue and disease atlases, we delineated the contribution of tissues
and associations to various diseases. Network analysis across body fluids elucidated
coordinated remodeling in the extracellular matrix and immune activation orchestrating
exercise-induced networks. Many exercise-responsive plasma proteins were robust across
age, sex, and exercise modalities, indicating a conserved systemic signature. Integration with
genetic data established exercise-regulated proteins as modulators of metabolic traits and
identified over 200 targeted by approved drugs, highlighting their impact on disease-relevant
pathways. This comprehensive atlas, available as an open-access resource
https://cbmr.ku.dk/research/research-groups/deshmukh-group/shiny-apps/, advances our
molecular insight into exercise adaptations and enables exerkine discovery, biomarker
development, and pharmacological exercise-mimetic strategies. Less
Mobile phones contaminated with pathogenic microorganisms have the potential to act as trojan horses The microbial signatures present on their surfaces most probably vary across different geographical regions As a result mobile phones belonging to international conference attendees may serve as a model for global microbial dissemination posing potential risks to public health and biosecurity This study aimed to profile the microbes present on mobile phones belonging to delegates attending an international scientific conference through use of metagenomic shotgun DNA sequencing Results A total of microbial hits were accumulated across mobile phones inclusive of bacteria viruses fungi and protozoa Of ... More
Mobile phones, contaminated with pathogenic microorganisms, have
the potential to act as “trojan horses”. The microbial signatures present on their surfaces most probably vary across different geographical regions. As a result, mobile phones belonging to
international conference attendees may serve as a model for global microbial dissemination,
posing potential risks to public health and biosecurity. This study aimed to profile the microbes present on mobile phones belonging to delegates
attending an international scientific conference through use of metagenomic shotgun DNA
sequencing. Results: A total of 2204 microbial hits were accumulated across 20 mobile phones inclusive of
882 bacteria, 1229 viruses, 88 fungi and 5 protozoa. Of particular concern was the identification of 65 distinct antibiotic resistance genes and 86 virulence genes. Plant, animal and human
pathogens, including ESKAPE and HACEK bacteria were found on mobile phones Less
the potential to act as “trojan horses”. The microbial signatures present on their surfaces most probably vary across different geographical regions. As a result, mobile phones belonging to
international conference attendees may serve as a model for global microbial dissemination,
posing potential risks to public health and biosecurity. This study aimed to profile the microbes present on mobile phones belonging to delegates
attending an international scientific conference through use of metagenomic shotgun DNA
sequencing. Results: A total of 2204 microbial hits were accumulated across 20 mobile phones inclusive of
882 bacteria, 1229 viruses, 88 fungi and 5 protozoa. Of particular concern was the identification of 65 distinct antibiotic resistance genes and 86 virulence genes. Plant, animal and human
pathogens, including ESKAPE and HACEK bacteria were found on mobile phones Less
Personalised cell therapies utilising T cell receptors TCRs show tremendous clinical promise though TCR synthesis and validation techniques lag far behind current TCR repertoire sequencing capacity To address this gap we developed makeTCR a modular TCR cloning system that enables rapid single-step fidelity assembly of human or murine TCR sequences into diverse expression vectors We provide pre-cloned modules for and TCRs as well as many native and engineered constant regions We show how implementing cell-free manufacturing both facilitates the propagation of precloned modules and allows testable TCR material to be synthesised in hours enabling patient-derived TCRs to be prototyped prior ... More
Personalised cell therapies utilising T cell receptors (TCRs) show tremendous clinical promise, though TCR synthesis and validation techniques lag far behind current TCR repertoire sequencing capacity. To address this gap we developed makeTCR: a modular TCR cloning system that enables rapid, single-step, 100% fidelity assembly of human or murine TCR sequences into diverse expression vectors. We provide pre-cloned modules for αβ and γδ TCRs, as well as many native and engineered constant regions. We show how implementing cell-free manufacturing both facilitates the propagation of precloned modules, and allows testable TCR material to be synthesised in 24 hours, enabling patient-derived TCRs to be prototyped prior to use in personalised cell therapies. makeTCR scales to making thousands of TCRs, at high fidelity and at substantially reduced cost. makeTCR is facilitated by a free, open-source, extensible, graphical platform to simplify, standardise, and accelerate TCR functionality testing for personalised medicine and beyond. Less
High-throughput experimentation HTE is a critical tool in modern pharmaceutical discovery and development The ability to perform multiple parallel experiments in miniaturized plate-based formats has revolutionized how chemical reactions are optimized HTE has been especially enabling for catalytic reactions where the complexity of factors influencing the outcome makes the HTE approach especially suitable We detail AstraZeneca s -year journey with HTE from early beginnings to a global community of HTE specialists that are critical to the delivery of our complex portfolio with reduced environmental impact With an emphasis on catalytic reactions we provide relevant case study examples from across discovery ... More
High-throughput experimentation (HTE) is a critical tool in modern pharmaceutical discovery and development. The ability to perform multiple parallel experiments in miniaturized plate-based formats has revolutionized how chemical reactions are optimized. HTE has been especially enabling for catalytic reactions, where the complexity of factors influencing the outcome makes the HTE approach especially suitable. We detail AstraZeneca’s 20-year journey with HTE, from early beginnings to a global community of HTE specialists that are critical to the delivery of our complex portfolio with reduced environmental impact. With an emphasis on catalytic reactions, we provide relevant case study examples from across discovery and development, discuss current technology, data science and workflows, and provide insights into where we see future advances in HTE. Less
The genus Streptomyces are valuable producers of antibiotics and other pharmaceutically important bioactive compounds Advances in molecular engineering tools such as CRISPR have provided some access to the metabolic potential of Streptomyces but efficient genetic engineering of strains is hindered by laborious and slow manual transformation protocols In this paper we present a semi-automated medium-throughput workflow for the introduction of recombinant DNA into Streptomyces spp using the affordable and open-sourced Opentrons OT- robotics platform To increase the accessibility of the workflow we provide an open-source protocol-creator ActinoMation ActinoMation is a literate programming environment using Python in Jupyter Notebook We validated ... More
The genus Streptomyces are valuable producers of antibiotics and other pharmaceutically important bioactive compounds. Advances in molecular engineering tools, such as CRISPR, have provided some access to the metabolic potential of Streptomyces, but efficient genetic engineering of strains is hindered by laborious and slow manual transformation protocols. In this paper, we present a semi-automated medium-throughput workflow for the introduction of recombinant DNA into Streptomyces spp. using the affordable and open-sourced Opentrons (OT-2) robotics platform. To increase the accessibility of the workflow we provide an open-source protocol-creator, ActinoMation. ActinoMation is a literate programming environment using Python in Jupyter Notebook. We validated the method by transforming Streptomyces coelicolor (M1152 and M1146), S. albidoflavus (J1047), and S. venezuelae (DSM40230) with the plasmids pSETGUS and pIJ12551. We demonstrate conjugation efficiencies of 3.33*10-3/0.33% for M1152 with pSETGUS and pIJ12551; 2.96*10-3/0.29%for M1146 with pSETGUS and pIJ12551; 1.21*10-5/0.0012% for J1047 with pSETGUS and 4.70*10-4/0.047% with pIJ12551, and 4.97*10-2/4.97% for DSM40230 with pSETGUS and 6.13*10-2 /6.13% with pIJ12551 with a false positive rate between 8.33% and 54.54%. Automation of the conjugation workflow facilitates a streamlined workflow on a larger scale without any evident loss of conjugation efficiency. Less
Single-cell transcriptomics is a key tool for unravelling metabolism and tissue diversity in model organisms Its potential for elucidating the ecological roles of microeukaryotes especially non-model ones remains largely unexplored This study employed the Smart-seq protocol on Ochromonas triangulata a microeukaryote lacking a reference genome showcasing how transcriptional states align with two distinct growth phases a fast-growing phase and a slow-growing phase Besides the two expected expression clusters each corresponding to either growth phase a third transcriptional state was identified across both growth phases Metabolic mapping revealed a boost of photosynthetic activity in the fast growth over the slow growth ... More
Single-cell transcriptomics is a key tool for unravelling metabolism and tissue diversity in model organisms. Its potential for elucidating the ecological roles of microeukaryotes, especially non-model ones, remains largely unexplored. This study employed the Smart-seq2 protocol on Ochromonas triangulata, a microeukaryote lacking a reference genome, showcasing how transcriptional states align with two distinct growth phases: a fast-growing phase and a slow-growing phase. Besides the two expected expression clusters, each corresponding to either growth phase, a third transcriptional state was identified across both growth phases. Metabolic mapping revealed a boost of photosynthetic activity in the fast growth over the slow growth stage, as well as down-regulation trend in pathways associated with ribosome functioning, CO2 fixation, and carbohydrate catabolism characteristic of the third transcriptional state. In addition, carry-over rRNA reads recapitulated the taxonomic identity of the target while revealing distinct bacterial communities, in co-culture with the eukaryote, each associated with distinct transcriptional states. This study underscores single-cell transcriptomics as a powerful tool for characterizing metabolic states in microeukaryotes without a reference genome, offering insights into unknown physiological states and individual-level interactions with different bacterial taxa. This approach holds broad applicability to describe the ecological roles of environmental microeukaryotes, culture-free and reference-free, surpassing alternative methods like metagenomics or metatranscriptomics. Less
Non-alcoholic fatty liver disease NAFLD - characterized by excess accumulation of fat in the liver - now affects one third of the world s population As NAFLD progresses extracellular matrix components including collagen accumulate in the liver causing tissue fibrosis a major determinant of disease severity and mortality To identify transcriptional regulators of fibrosis we computationally inferred the activity of transcription factors TFs relevant to fibrosis by profiling the matched transcriptomes and epigenomes of human liver biopsies from a deeply-characterized cohort of patients spanning the full histopathologic spectrum of NAFLD CRISPR-based genetic knockout of the top TFs identified ZNF as ... More
Non-alcoholic fatty liver disease (NAFLD) - characterized by excess accumulation of fat in the liver - now affects one third of the world’s population. As NAFLD progresses, extracellular matrix components including collagen accumulate in the liver causing tissue fibrosis, a major determinant of disease severity and mortality. To identify transcriptional regulators of fibrosis, we computationally inferred the activity of transcription factors (TFs) relevant to fibrosis by profiling the matched transcriptomes and epigenomes of 108 human liver biopsies from a deeply-characterized cohort of patients spanning the full histopathologic spectrum of NAFLD. CRISPR-based genetic knockout of the top 100 TFs identified ZNF469 as a regulator of collagen expression in primary human hepatic stellate cells (HSCs). Gain- and loss-of-function studies established that ZNF469 regulates collagen genes and genes involved in matrix homeostasis through direct binding to gene bodies and regulatory elements. By integrating multiomic large-scale profiling of human biopsies with extensive experimental validation we demonstrate that ZNF469 is a transcriptional regulator of collagen in HSCs. Overall, these data nominate ZNF469 as a previously unrecognized determinant of NAFLD-associated liver fibrosis. Less
ackground The Safety and Immunogenicity of COVID- Vaccines in Systemic Autoimmune-Mediated Inflammatory Diseases SUCCEED study was created to better understand COVID- vaccination in immune-mediated inflammatory disease IMID Knowing the frequency of COVID- breakthrough infections is important particularly in IMID Our objective was to assess these events in IMID Methods We prospectively studied IMID participants who had received three COVID- vaccine doses Individuals provided saliva samples monthly September to August These were evaluated by polymerase chain reaction PCR for SARS-CoV- We also assessed antibodies against SARS-CoV- anti-spike SmT receptor binding domain RBD and nucleocapsid NP based on dried blood spots Multivariable ... More
ackground: The Safety and Immunogenicity of COVID-19 Vaccines in Systemic Autoimmune-Mediated Inflammatory Diseases (SUCCEED) study was created to better understand COVID-19 vaccination in immune-mediated inflammatory disease (IMID). Knowing the frequency of COVID-19 breakthrough infections is important, particularly in IMID. Our objective was to assess these events in IMID. Methods: We prospectively studied IMID participants who had received ≥three COVID-19 vaccine doses. Individuals provided saliva samples monthly (September 2022 to August 2023). These were evaluated by polymerase chain reaction (PCR) for SARS-CoV-2. We also assessed antibodies against SARS-CoV-2 (anti-spike, SmT1, receptor binding domain, RBD, and nucleocapsid, NP) based on dried blood spots. Multivariable general estimating equation regression produced odd ratios (OR) for PCR SARS-CoV-2 positivity, related to demographics, immunosuppressives, and antibody levels. Results: Diagnoses included rheumatoid arthritis RA (N = 161, 44% of the total), systemic lupus, psoriatic arthritis, spondylarthritis, vasculitis, systemic sclerosis, and inflammatory bowel disease. Of the 366 participants, most were taking immunosuppressive medication. Of 1266 saliva samples, 56 (5.1%) were positive for SARS-CoV-2 on PCR. Higher anti-SmT1 antibodies were inversely associated with SARS-CoV-2 detection on PCR (adjusted OR 0.66, 95% confidence interval 0.45–0.97). Antibodies to SmT1, RBD, and NP were correlated and thus could not be included in a single model, but when anti-RBD was used in place of anti-SmT1, the results were similar. No other factor (including prior COVID-19 infection) was clearly associated with SARS-CoV-2 detection. Conclusions: This is the first study of SARS-CoV-2 in a large prospective cohort of triple (or more) vaccinated individuals with IMIDs. Anti-SmT1 antibodies appeared to be protective against later SARS-CoV-2 positivity, although recent past infection was not clearly related. This suggests the importance of maintaining robust vaccine-induced immunity through vaccination in IMID. Less
The rise of drug-resistant fungal pathogens including Candida auris highlights the urgent need for novel antifungal therapies We developed a cost-effective platform combining microbial extract prefractionation with rapid MS MS-bioinformatics-based dereplication to efficiently prioritize new antifungal scaffolds Screening C auris and C albicans revealed novel lipopeptaibiotics coniotins from Coniochaeta hoffmannii WAC which were undetectable in crude extracts Coniotins exhibited potent activity against critical fungal pathogens on the WHO Fungal Priority Pathogens List including C albicans C neoformans multidrug-resistant C auris and Aspergillus fumigatus with high selectivity and low resistance potential Coniotin A targets -glucan compromising fungal cell wall integrity remodelling ... More
The rise of drug-resistant fungal pathogens, including Candida auris, highlights the urgent need for novel antifungal therapies. We developed a cost-effective platform combining microbial extract prefractionation with rapid MS/MS-bioinformatics-based dereplication to efficiently prioritize new antifungal scaffolds. Screening C. auris and C. albicans revealed novel lipopeptaibiotics, coniotins, from Coniochaeta hoffmannii WAC11161, which were undetectable in crude extracts. Coniotins exhibited potent activity against critical fungal pathogens on the WHO Fungal Priority Pathogens List, including C. albicans, C. neoformans, multidrug-resistant C. auris, and Aspergillus fumigatus, with high selectivity and low resistance potential. Coniotin A targets β-glucan, compromising fungal cell wall integrity, remodelling, and sensitizing C. auris to caspofungin. Identification of a PKS-NRPS biosynthetic gene cluster further enables the discovery of related clusters encoding potential novel lipopeptaibiotics. This study demonstrates the power of natural product prefractionation in uncovering bioactive scaffolds and introduces coniotins as promising candidates for combating multidrug-resistant fungal pathogens. Less
Transcription factors of the bHLH-PAS family play vital roles in animal development physiology and disease Two members of the family require binding of low-molecular weight ligands for their activity the vertebrate aryl hydrocarbon receptor AHR and the insect juvenile hormone receptor JHR In the fly Drosophila melanogaster the paralogous proteins GCE and MET constitute the ligand-binding component of JHR complexes Whilst GCE MET and AHR are phylogenetically heterologous their mode of action is similar JHR is targeted by several synthetic agonists that serve as insecticides disrupting the insect endocrine system AHR is an important regulator of human endocrine homeostasis and ... More
Transcription factors of the bHLH-PAS family play vital roles in animal development, physiology, and disease. Two members of the family require binding of low-molecular weight ligands for their activity: the vertebrate aryl hydrocarbon receptor (AHR) and the insect juvenile hormone receptor (JHR). In the fly Drosophila melanogaster, the paralogous proteins GCE and MET constitute the ligand-binding component of JHR complexes. Whilst GCE/MET and AHR are phylogenetically heterologous, their mode of action is similar. JHR is targeted by several synthetic agonists that serve as insecticides disrupting the insect endocrine system. AHR is an important regulator of human endocrine homeostasis and it responds to environmental pollutants and endocrine disruptors. Whether AHR signaling is affected by compounds that can activate JHR has not been reported. To address this question, we screened a chemical library of 50,000 compounds to identify 93 novel JHR agonists in a reporter system based on Drosophila cells. Of these compounds, 26% modulated AHR signaling in an analogous reporter assay in a human cell line, indicating a significant overlap in the agonist repertoires of the two receptors. To explore the structural features of agonist-dependent activation of JHR and AHR, we compared the ligand-binding cavities and their interactions with selective and common ligands of AHR and GCE. Molecular dynamics modeling revealed ligand-specific as well as conserved side chains within the respective cavities. Significance of predicted interactions was supported through site-directed mutagenesis. The results have indicated that synthetic insect juvenile hormone agonists might interfere with AHR signaling in human cells. Less
T cells are key players in adaptive immunity The specificity of T cells is determined by the sequences of the hypervariable T cell receptor TCR and chains Although bulk TCR sequencing offers a cost-effective approach for in-depth TCR repertoire profiling it does not provide chain pairings which are essential for determining T cell specificity In contrast single-cell TCR sequencing technologies produce paired chain data but are limited in throughput to thousands of cells and are cost-prohibitive for cohort-scale studies Here we present TIRTL-seq Throughput-Intensive Rapid TCR Library sequencing a novel approach that generates ready-to-sequence TCR libraries from live cells in ... More
ɑ/β T cells are key players in adaptive immunity. The specificity of T cells is determined by the sequences of the hypervariable T cell receptor (TCR) ɑ and β chains. Although bulk TCR sequencing offers a cost-effective approach for in-depth TCR repertoire profiling, it does not provide chain pairings, which are essential for determining T cell specificity. In contrast, single-cell TCR sequencing technologies produce paired chain data, but are limited in throughput to thousands of cells and are cost-prohibitive for cohort-scale studies. Here, we present TIRTL-seq (Throughput-Intensive Rapid TCR Library sequencing), a novel approach that generates ready-to-sequence TCR libraries from live cells in less than 7 hours. The protocol is optimized for use with non-contact liquid handlers in an automation-friendly 384-well plate format. Reaction volume miniaturization reduces library preparation costs to <$0.50 per well. The core principle of TIRTL-seq is the parallel generation of hundreds of libraries providing multiple biological replicates from a single sample that allows precise inference of both frequencies of individual clones and TCR chain pairings from well-occurrence patterns. We demonstrate scalability of our approach up to 1 million unique paired αβTCR clonotypes corresponding to over 30 million T cells per sample at a cost of less than $2000. For a sample of 10 million cells the cost is ~$200. We benchmarked TIRTL-seq against state-of-the-art 5'RACE bulk TCR-seq and 10x Genomics Chromium technologies on longitudinal samples. We show that TIRTL-seq is able to quantitatively identify expanding and contracting clonotypes between timepoints while providing accurate TCR chain pairings, including distinct temporal dynamics of SARS-CoV-2-specific and EBV-specific CD8+ T cell responses after infection. While clonal expansion was followed by sharp contraction for SARS-CoV-2 specific TCRs, EBV-specific TCRs remained stable once established. The sequences of both ɑ and β TCR chains are essential for determining T cell specificity. As the field moves towards greater applications in diagnostics and immunotherapy that rely on TCR specificity, we anticipate that our scalable paired TCR sequencing methodology will be instrumental for collecting large paired-chain datasets and ultimately extracting therapeutically relevant information from the TCR repertoire. Less
The SARS-CoV- main protease Mpro is essential for viral replication because it is responsible for the processing of most of the non-structural proteins encoded by the virus Inhibition of Mpro prevents viral replication and therefore constitutes an attractive antiviral strategy We set out to develop a high-throughput Mpro enzymatic activity assay using fluorescently labeled peptide substrates A library of fluorogenic substrates of various lengths sequences and dye quencher positions was prepared and tested against full length SARS-CoV- Mpro enzyme for optimal activity The addition of buffers containing strongly hydrated kosmotropic anion salts such as citrate from the Hofmeister series significantly ... More
The SARS-CoV-2 main protease (Mpro) is essential for viral replication because it is responsible for the processing of most of the non-structural proteins encoded by the virus. Inhibition of Mpro prevents viral replication and therefore constitutes an attractive antiviral strategy. We set out to develop a high-throughput Mpro enzymatic activity assay using fluorescently labeled peptide substrates. A library of fluorogenic substrates of various lengths, sequences and dye/quencher positions was prepared and tested against full length SARS-CoV-2 Mpro enzyme for optimal activity. The addition of buffers containing strongly hydrated kosmotropic anion salts, such as citrate, from the Hofmeister series significantly boosted the enzyme activity and enhanced the assay detection limit, enabling the ranking of sub-nanomolar inhibitors without relying on the low-throughput Morrison equation method. By comparing cooperativity in citrate or non-citrate buffer while titrating the Mpro enzyme concentration, we found full positive cooperativity of Mpro with citrate buffer at less than one nanomolar (nM), but at a much higher enzyme concentration (∼320 nM) with non-citrate buffer. In addition, using a tight binding Mpro inhibitor, we confirmed there was only one active catalytical site in each Mpro monomer. Since cooperativity requires at least two binding sites, we hypothesized that citrate facilitates dimerization of Mpro at sub-nanomolar concentration as one of the mechanisms enhances Mpro catalytic efficiency. This assay has been used in high-throughput screening and structure activity relationship (SAR) studies to support medicinal chemistry efforts. IC50 values determined in this assay correlates well with EC50 values generated by a SARS-CoV-2 antiviral assay after adjusted for cell penetration. Less
Menstrual toxic shock syndrome mTSS is a rare but severe disorder associated with the use of menstrual products such as high-absorbency tampons and is caused by Staphylococcus aureus strains that produce the toxic shock syndrome toxin- TSST- superantigen Herein we screened a library of small bioactive molecules for the ability to inhibit transcription of the TSST- gene without inhibiting the growth of S aureus The dominant positive regulator of TSST- is the SaeRS two-component system TCS and we identified phenazopyridine hydrochloride PP-HCl that repressed the production of TSST- by inhibiting the kinase function of SaeS PP-HCl competed with ATP for ... More
Menstrual toxic shock syndrome (mTSS) is a rare but severe disorder associated with the use of menstrual products such as high-absorbency tampons and is caused by Staphylococcus aureus strains that produce the toxic shock syndrome toxin-1 (TSST-1) superantigen. Herein, we screened a library of 3920 small bioactive molecules for the ability to inhibit transcription of the TSST-1 gene without inhibiting the growth of S. aureus. The dominant positive regulator of TSST-1 is the SaeRS two-component system (TCS), and we identified phenazopyridine hydrochloride (PP-HCl) that repressed the production of TSST-1 by inhibiting the kinase function of SaeS. PP-HCl competed with ATP for binding of the kinase SaeS leading to decreased phosphorylation of SaeR and reduced expression of TSST-1 as well as several other secreted virulence factors known to be regulated by SaeRS. PP-HCl targets the virulence of S. aureus, and it also decreases the impact of TSST-1 on human lymphocytes without affecting the healthy vaginal microbiota. Our findings demonstrate the promising potential of PP-HCl as a therapeutic strategy against mTSS. Less
Background Neutrophils the most abundant white blood cells in humans play pivotal roles in innate immunity rapidly migrating to sites of infection and inflammation to phagocytose neutralize and eliminate invading pathogens Neutrophil extracellular trap NET formation is increasingly recognized as an essential rapid innate immune response but when dysregulated it contributes to pathogenesis of sepsis and immunothrombotic disease Objectives Current NETosis models are limited routinely employing nonphysiological triggers that can bypass natural NET regulatory pathways Models utilizing isolated neutrophils and immortalized cell lines do not reflect the complex biology underlying neutrophil activation and NETosis that occurs in whole blood To ... More
Background
Neutrophils, the most abundant white blood cells in humans, play pivotal roles in innate immunity, rapidly migrating to sites of infection and inflammation to phagocytose, neutralize, and eliminate invading pathogens. Neutrophil extracellular trap (NET) formation is increasingly recognized as an essential rapid innate immune response, but when dysregulated, it contributes to pathogenesis of sepsis and immunothrombotic disease.
Objectives
Current NETosis models are limited, routinely employing nonphysiological triggers that can bypass natural NET regulatory pathways. Models utilizing isolated neutrophils and immortalized cell lines do not reflect the complex biology underlying neutrophil activation and NETosis that occurs in whole blood. To our knowledge, we report the first human ex vivo model utilizing naturally occurring molecules to induce NETosis in whole blood. This approach could be used for drug screening and, importantly, inadvertent activators of NETosis.
Methods
Here we describe a novel, high-throughput ex vivo whole blood–induced NETosis model using combinatorial pooling of native NETosis-inducing factors in a more biologically relevant Synthetic-Sepsis model.
Results
We found different combinations of factors evoked distinct neutrophil responses in the rate of NET generation and/or magnitude of NETosis. Despite interdonor variability, similar sets of proinflammatory molecules induced consistent responses across donors. We found that at least 3 biological triggers were necessary to induce NETosis in our system including either tumor necrosis factor-α or lymphotoxin-α.
Conclusion
These findings emphasize the importance of investigating neutrophil physiology in a biologically relevant context to enable a better understanding of disease pathology, risk factors, and therapeutic targets, potentially providing novel strategies for disease intervention and treatment. Less
Neutrophils, the most abundant white blood cells in humans, play pivotal roles in innate immunity, rapidly migrating to sites of infection and inflammation to phagocytose, neutralize, and eliminate invading pathogens. Neutrophil extracellular trap (NET) formation is increasingly recognized as an essential rapid innate immune response, but when dysregulated, it contributes to pathogenesis of sepsis and immunothrombotic disease.
Objectives
Current NETosis models are limited, routinely employing nonphysiological triggers that can bypass natural NET regulatory pathways. Models utilizing isolated neutrophils and immortalized cell lines do not reflect the complex biology underlying neutrophil activation and NETosis that occurs in whole blood. To our knowledge, we report the first human ex vivo model utilizing naturally occurring molecules to induce NETosis in whole blood. This approach could be used for drug screening and, importantly, inadvertent activators of NETosis.
Methods
Here we describe a novel, high-throughput ex vivo whole blood–induced NETosis model using combinatorial pooling of native NETosis-inducing factors in a more biologically relevant Synthetic-Sepsis model.
Results
We found different combinations of factors evoked distinct neutrophil responses in the rate of NET generation and/or magnitude of NETosis. Despite interdonor variability, similar sets of proinflammatory molecules induced consistent responses across donors. We found that at least 3 biological triggers were necessary to induce NETosis in our system including either tumor necrosis factor-α or lymphotoxin-α.
Conclusion
These findings emphasize the importance of investigating neutrophil physiology in a biologically relevant context to enable a better understanding of disease pathology, risk factors, and therapeutic targets, potentially providing novel strategies for disease intervention and treatment. Less
Drug sensitivity testing of patient-derived tumor organoids PDTOs is a promising tool for personalizing cancer treatment Here we present a protocol for generation of and high-throughput drug testing with PDTOs We describe detailed steps for PDTO establishment from colorectal cancer tissues preparation of PDTOs for high-throughput drug testing and quantification of drug testing results using image analysis This protocol provides a standardized workflow for PDTO testing of standard-of-care therapies along with exploring the activity of new agents for translational research
Methods of studying eukaryotic cell responses to a perturbation or of stratifying eukaryotic cells or cell lines into one or more subgroups are described The methods involve perturbing a library of cells or cell lines in the same manner and observing how the cells respond to the same perturbation The observation may be via a high throughput screening method for example cell painting and the perturbation may be for example exposure to a therapeutic agent The methods may be used for grouping cells or cell lines that respond similarly to a given therapeutic agent which may be useful for identifying ... More
Methods of studying eukaryotic cell responses to a perturbation, or of stratifying eukaryotic cells or cell lines into one or more subgroups are described. The methods involve perturbing a library of cells or cell lines in the same manner, and observing how the cells respond to the same perturbation. The observation may be via a high throughput screening method, for example, cell painting; and the perturbation may be, for example, exposure to a therapeutic agent.The methods may be used for grouping cells or cell lines that respond similarly to a given therapeutic agent, which may be useful for identifying patient groups and selecting appropriate treatments. Less
Nowadays an efficient and robust virtual screening procedure is crucial in the drug discovery process especially when performed on large and chemically diverse databases Virtual screening methods like molecular docking and classic QSAR models are limited in their ability to handle vast numbers of compounds and to learn from scarce data respectively In this study we introduce a universal methodology that uses a machine learning-based approach to predict docking scores without the need for time-consuming molecular docking procedures The developed protocol yielded times faster binding energy predictions than classical docking-based screening The proposed predictive model learns from docking results allowing ... More
Nowadays, an efficient and robust virtual screening procedure is crucial in the drug discovery process, especially when performed on large and chemically diverse databases. Virtual screening methods, like molecular docking and classic QSAR models, are limited in their ability to handle vast numbers of compounds and to learn from scarce data, respectively. In this study, we introduce a universal methodology that uses a machine learning-based approach to predict docking scores without the need for time-consuming molecular docking procedures. The developed protocol yielded 1000 times faster binding energy predictions than classical docking-based screening. The proposed predictive model learns from docking results, allowing users to choose their preferred docking software without relying on insufficient and incoherent experimental activity data. The methodology described employs multiple types of molecular fingerprints and descriptors to construct an ensemble model that further reduces prediction errors and is capable of delivering highly precise docking score values for monoamine oxidase ligands, enabling faster identification of promising compounds. An extensive pharmacophore-constrained screening of the ZINC database resulted in a selection of 24 compounds that were synthesized and evaluated for their biological activity. A preliminary screen discovered weak inhibitors of MAO-A with a percentage efficiency index close to a known drug at the lowest tested concentration. The approach presented here can be successfully applied to other biological targets as target-specific knowledge is not incorporated at the screening phase. Less
The activities of the phospholipase C gamma PLC and enzymes are essential for numerous cellular processes Unsurprisingly dysregulation of PLC or PLC activity is associated with multiple maladies including immune disorders cancers and neurodegenerative diseases Therefore the modulation of either of these two enzymes has been suggested as a therapeutic strategy to combat these diseases To aid in the discovery of PLC family enzyme modulators that could be developed into therapeutic agents we have synthesized a high-throughput screening-amenable micellular fluorogenic substrate called C CF -coumarin Herein the ability of PLC and PLC to enzymatically process C CF -coumarin was confirmed ... More
The activities of the phospholipase C gamma (PLCγ) 1 and 2 enzymes are essential for numerous cellular processes. Unsurprisingly, dysregulation of PLCγ1 or PLCγ2 activity is associated with multiple maladies including immune disorders, cancers, and neurodegenerative diseases. Therefore, the modulation of either of these two enzymes has been suggested as a therapeutic strategy to combat these diseases. To aid in the discovery of PLCγ family enzyme modulators that could be developed into therapeutic agents, we have synthesized a high-throughput screening-amenable micellular fluorogenic substrate called C16CF3-coumarin. Herein, the ability of PLCγ1 and PLCγ2 to enzymatically process C16CF3-coumarin was confirmed, the micellular assay conditions were optimized, and the kinetics of the reaction were determined. A proof-of-principle pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) was performed. This new substrate allows for an additional screening methodology to identify modulators of the PLCγ family of enzymes. Less
ADP-ribosyltransferases PARP and PARP play a major role in DNA repair mechanism by detecting the DNA damage and inducing poly-ADP-ribosylation dependent chromatin relaxation and recruitment of repair proteins Catalytic PARP inhibitors are used as anticancer drugs especially in the case of tumors arising from sensitizing mutations Recently a study showed that Histone PARylation Factor HPF forms a joint active site with PARP The interaction of HPF with PARP alters the modification site from Aspartate Glutamate to Serine which has been shown to be a key ADP-ribosylation event in the context of DNA damage Therefore disruption of PARP -HPF interaction could ... More
ADP-ribosyltransferases PARP1 and PARP2 play a major role in DNA repair mechanism by detecting the DNA damage and inducing poly-ADP-ribosylation dependent chromatin relaxation and recruitment of repair proteins. Catalytic PARP inhibitors are used as anticancer drugs especially in the case of tumors arising from sensitizing mutations. Recently, a study showed that Histone PARylation Factor (HPF1) forms a joint active site with PARP1/2. The interaction of HPF1 with PARP1/2 alters the modification site from Aspartate/Glutamate to Serine, which has been shown to be a key ADP-ribosylation event in the context of DNA damage. Therefore, disruption of PARP1/2-HPF1 interaction could be an alternative strategy for drug development to block the PARP1/2 activity. In this study, we describe a FRET based high-throughput screening assay to screen inhibitor libraries against PARP-HPF1 interaction. We optimized the conditions for FRET signal and verified the interaction by competing the FRET pair in multiple ways. The assay is robust and easy to automate. Validatory screening showed the robust performance of the assay, and we discovered two compounds Dimethylacrylshikonin and Alkannin, with µM inhibition potency against PARP1/2-HPF1 interaction. The assay will facilitate the discovery of inhibitors against HPF1-PARP1/2 complex and to develop potentially new effective anticancer agents. Less
Exposure to environmental pollutants is linked to numerous toxic outcomes warranting concern about the effect of pollutants on human health To assess the threat of pollutant exposure it is essential to understand their biological activity Unfortunately gaps remain for many pollutants specific biological activity and molecular targets A superfamily of signaling proteins G-protein-coupled receptors GPCRs has been shown as potential targets for pollutant activity However research investigating the pollutant activity at the GPCRome is scarce This work explores pollutant activity across a library of human GPCRs by leveraging modern high-throughput screening techniques devised for drug discovery and pharmacology We designed ... More
Exposure to environmental pollutants is linked to numerous toxic outcomes, warranting concern about the effect of pollutants on human health. To assess the threat of pollutant exposure, it is essential to understand their biological activity. Unfortunately, gaps remain for many pollutants’ specific biological activity and molecular targets. A superfamily of signaling proteins, G-protein-coupled receptors (GPCRs), has been shown as potential targets for pollutant activity. However, research investigating the pollutant activity at the GPCRome is scarce. This work explores pollutant activity across a library of human GPCRs by leveraging modern high-throughput screening techniques devised for drug discovery and pharmacology. We designed and implemented a pilot screen of eight pollutants at 314 human GPCRs and discovered specific polychlorinated biphenyl (PCB) activity at sphingosine-1-phosphate and melatonin receptors. The method utilizes open-source resources available to academic and governmental institutions to enable future campaigns that screen large numbers of pollutants. Thus, we present a novel high-throughput approach to assess the biological activity and specific targets of pollutants. Less
We herein describe the development and application of a modular technology platform which incorporates recent advances in plate-based microscale chemistry automated purification in situ quantification and robotic liquid handling to enable rapid access to high-quality chemical matter already formatted for assays In using microscale chemistry and thus consuming minimal chemical matter the platform is not only efficient but also follows green chemistry principles By reorienting existing high-throughput assay technology the platform can generate a full package of relevant data on each set of compounds in every learning cycle The multiparameter exploration of chemical and property space is hereby driven by ... More
We herein describe the development and application of a modular technology platform which incorporates recent advances in plate-based microscale chemistry, automated purification, in situ quantification, and robotic liquid handling to enable rapid access to high-quality chemical matter already formatted for assays. In using microscale chemistry and thus consuming minimal chemical matter, the platform is not only efficient but also follows green chemistry principles. By reorienting existing high-throughput assay technology, the platform can generate a full package of relevant data on each set of compounds in every learning cycle. The multiparameter exploration of chemical and property space is hereby driven by active learning models. The enhanced compound optimization process is generating knowledge for drug discovery projects in a time frame never before possible. Less
Predictive drug testing of patient-derived tumor organoids PDTOs holds promise for personalizing treatment of metastatic colorectal cancer mCRC but prospective data are limited to chemotherapy regimens with conflicting results We describe a unified framework for PDTO-based predictive testing across standard-of-care chemotherapy and biologic and targeted therapy options In an Australian community cohort PDTO predictions based on treatment-naive patients n and response rates from first-line mCRC clinical trials achieve accuracy for forecasting responses in patients receiving palliative treatments patients treatments Similar assay accuracy is achieved in a prospective study of third-line or later mCRC treatment AGITG FORECAST- n patients Resistant predictions ... More
Predictive drug testing of patient-derived tumor organoids (PDTOs) holds promise for personalizing treatment of metastatic colorectal cancer (mCRC), but prospective data are limited to chemotherapy regimens with conflicting results. We describe a unified framework for PDTO-based predictive testing across standard-of-care chemotherapy and biologic and targeted therapy options. In an Australian community cohort, PDTO predictions based on treatment-naive patients (n = 56) and response rates from first-line mCRC clinical trials achieve 83% accuracy for forecasting responses in patients receiving palliative treatments (18 patients, 29 treatments). Similar assay accuracy is achieved in a prospective study of third-line or later mCRC treatment, AGITG FORECAST-1 (n = 30 patients). “Resistant” predictions are associated with inferior progression-free survival; misclassification rates are similar by regimen. Liver metastases are the optimal site for sampling, with testing achievable within 7 weeks for 68.8% cases. Our findings indicate that PDTO drug panel testing can provide predictive information for multifarious standard-of-care therapies for mCRC. Less
Microbial natural products are specialized metabolites that are sources of many bioactive compounds including antibiotics antifungals antiparasitics anticancer agents and probes of biology The assembly of libraries of producers of natural products has traditionally been the province of the pharmaceutical industry This sector has gathered significant historical collections of bacteria and fungi to identify new drug leads with outstanding outcomes - upwards of of drug scaffolds originate from such libraries Despite this success the repeated rediscovery of known compounds and the resultant diminishing chemical novelty contributed to a pivot from this source of bioactive compounds toward more tractable synthetic compounds ... More
Microbial natural products are specialized metabolites that are sources of many bioactive
compounds including antibiotics, antifungals, antiparasitics, anticancer agents, and probes of
biology. The assembly of libraries of producers of natural products has traditionally been the
province of the pharmaceutical industry. This sector has gathered significant historical
collections of bacteria and fungi to identify new drug leads with outstanding outcomes - upwards of 60% of drug scaffolds originate from such libraries. Despite this success, the repeated rediscovery of known compounds and the resultant diminishing chemical novelty contributed to a pivot from this source of bioactive compounds toward more tractable synthetic compounds in the drug industry. The advent of advanced mass spectrometry tools, along with rapid whole genome sequencing and in silico identification of biosynthetic gene clusters that encode the machinery necessary for the synthesis of specialized metabolites, offers the opportunity to revisit microbial natural product libraries with renewed vigor. Assembling a suitable library of microbes and extracts for screening requires the investment of resources and the development of methods that have customarily been the proprietary purview of large pharmaceutical companies. Here, we
report a perspective on our efforts to assemble a library of natural product-producing microbes
and the establishment of methods to extract and fractionate bioactive compounds using resources available to most academic labs. We validate the library and approach through a series of screens for antimicrobial and cytotoxic agents. This work serves as a blueprint for establishing libraries of microbial natural product producers and bioactive extract fractions suitable for screens of bioactive compounds. Less
compounds including antibiotics, antifungals, antiparasitics, anticancer agents, and probes of
biology. The assembly of libraries of producers of natural products has traditionally been the
province of the pharmaceutical industry. This sector has gathered significant historical
collections of bacteria and fungi to identify new drug leads with outstanding outcomes - upwards of 60% of drug scaffolds originate from such libraries. Despite this success, the repeated rediscovery of known compounds and the resultant diminishing chemical novelty contributed to a pivot from this source of bioactive compounds toward more tractable synthetic compounds in the drug industry. The advent of advanced mass spectrometry tools, along with rapid whole genome sequencing and in silico identification of biosynthetic gene clusters that encode the machinery necessary for the synthesis of specialized metabolites, offers the opportunity to revisit microbial natural product libraries with renewed vigor. Assembling a suitable library of microbes and extracts for screening requires the investment of resources and the development of methods that have customarily been the proprietary purview of large pharmaceutical companies. Here, we
report a perspective on our efforts to assemble a library of natural product-producing microbes
and the establishment of methods to extract and fractionate bioactive compounds using resources available to most academic labs. We validate the library and approach through a series of screens for antimicrobial and cytotoxic agents. This work serves as a blueprint for establishing libraries of microbial natural product producers and bioactive extract fractions suitable for screens of bioactive compounds. Less
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection It is responsible for US deaths annually Neutrophils are an integral part of the innate immune response and rapidly clear pathogens from circulation using neutrophil extracellular traps NETs which are released through a process called NETosis NETs prevent dissemination of pathogens by entrapment in externalized chromatin containing deactivating enzymes While we have learned much about the mechanisms underlying NETosis we are yet to translate it to improved therapies or patient outcomes This gap may be attributable to the models used to study NETosis Current models used ... More
Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection (1). It is responsible for ~370,000 US deaths annually (2). Neutrophils are an integral part of the innate immune response and rapidly clear pathogens from circulation using neutrophil extracellular traps (NETs), which are released through a process called NETosis (3). NETs prevent dissemination of pathogens by entrapment in externalized chromatin containing deactivating enzymes. While we have learned much about the mechanisms underlying NETosis, we are yet to translate it to improved therapies or patient outcomes. This gap may be attributable to the models used to study NETosis. Current models used to investigate NETosis are limited and routinely employ unnatural triggers such as phorbol 12-myristate 13-acetate (PMA). PMA is not a physiological trigger present in the immune system and may bypass the natural pathways that regulate NETs production. Mouse models that use isolated neutrophils and neutrophil-like cells induced from immortalized cell lines do not completely reflect the complex cellular and molecular biology underlying neutrophil activation and NETosis, especially in a whole-blood environment. Therefore, it is crucial to study how specific factors, known to be upregulated in disease, interact and potentially induce NETosis. Here we use high-throughput screening and natural NETosis triggers to develop a more biologically relevant ex vivo NETosis (Synthetic-Sepsis™) model.
Whole blood was collected from healthy donors and aliquoted into a 384 well plate using a Formulatrix Mantis liquid handler. This plate contained small molecules associated with neutrophils or NETosis activation, such as interleukins: Il-1b, IL-5, IL-6, IL-8, IL-15, IL-17, IL-18 and other molecules TNF- α, LT-α, IFN-γ, G-CSF, GM-CSF, E-selectin, PAF-16, CXCL1, CXCL2, LTB4, CXCL5, CCL2, CCL3, fMLP, Ferritin, HMGB1, C5a and LPS. We used a combinatorial pooling strategy designed using JMP software to identify which combinations of small molecules could stimulate NET formation. NETosis was assessed using Sytox green intercalation at 5 minute intervals for up to 24 hours using a Molecular Devices plate reader. PMA was utilized as a positive control for NETosis induction at varying concentrations.
Using our combinatorial pooling approach of the various factors, we successfully induced NETosis in an ex vivo whole blood system using naturally occurring cytokines and chemokines at physiologically relevant concentrations. We found that different combinations of factors evoke distinct neutrophil responses both in the time of NET generation and/or magnitude of NET-associated intercalation signal. We observed inter-donor variability in response time and amplitude however, similar small molecule pools induced consistent responses across donors. Furthermore, our findings suggest that at least four naturally occurring factors are necessary to induce NETosis in our system. Although some factors activate similar pathways, they are unable to induce a signal alone and as the number of factors increased beyond four, there was an enhanced NET response. Interestingly, we found either TNF-α or LT-α was required to cause a NETosis response, underlining the potentially significant roles these factors play in inflammatory disease. These results suggest an underlying master regulatory mechanism, such that certain factors are essential but not individually sufficient to trigger NETosis.
To our knowledge, we report the first ex-vivo model using naturally occurring cytokines and chemokines to induce NETosis in whole blood. These findings emphasize the importance of expanding our understanding of neutrophil physiology in a biologically relevant context with physiological triggers to induce NETosis. This approach could reveal new dimensions in our understanding of disease pathology and risk factors and might unearth potential therapeutic targets providing novel strategies for disease intervention and treatment. Further investigation of these factors is underway to further understand the release of NETs in natural and pathological states. Less
Whole blood was collected from healthy donors and aliquoted into a 384 well plate using a Formulatrix Mantis liquid handler. This plate contained small molecules associated with neutrophils or NETosis activation, such as interleukins: Il-1b, IL-5, IL-6, IL-8, IL-15, IL-17, IL-18 and other molecules TNF- α, LT-α, IFN-γ, G-CSF, GM-CSF, E-selectin, PAF-16, CXCL1, CXCL2, LTB4, CXCL5, CCL2, CCL3, fMLP, Ferritin, HMGB1, C5a and LPS. We used a combinatorial pooling strategy designed using JMP software to identify which combinations of small molecules could stimulate NET formation. NETosis was assessed using Sytox green intercalation at 5 minute intervals for up to 24 hours using a Molecular Devices plate reader. PMA was utilized as a positive control for NETosis induction at varying concentrations.
Using our combinatorial pooling approach of the various factors, we successfully induced NETosis in an ex vivo whole blood system using naturally occurring cytokines and chemokines at physiologically relevant concentrations. We found that different combinations of factors evoke distinct neutrophil responses both in the time of NET generation and/or magnitude of NET-associated intercalation signal. We observed inter-donor variability in response time and amplitude however, similar small molecule pools induced consistent responses across donors. Furthermore, our findings suggest that at least four naturally occurring factors are necessary to induce NETosis in our system. Although some factors activate similar pathways, they are unable to induce a signal alone and as the number of factors increased beyond four, there was an enhanced NET response. Interestingly, we found either TNF-α or LT-α was required to cause a NETosis response, underlining the potentially significant roles these factors play in inflammatory disease. These results suggest an underlying master regulatory mechanism, such that certain factors are essential but not individually sufficient to trigger NETosis.
To our knowledge, we report the first ex-vivo model using naturally occurring cytokines and chemokines to induce NETosis in whole blood. These findings emphasize the importance of expanding our understanding of neutrophil physiology in a biologically relevant context with physiological triggers to induce NETosis. This approach could reveal new dimensions in our understanding of disease pathology and risk factors and might unearth potential therapeutic targets providing novel strategies for disease intervention and treatment. Further investigation of these factors is underway to further understand the release of NETs in natural and pathological states. Less
The efficacy of aminoglycoside antibiotics is waning due to the acquisition of diverse resistance mechanisms by bacteria Among the most prevalent are aminoglycoside acetyltransferases AACs that inactivate the antibiotics through acetyl coenzyme A-mediated modification Most AACs are members of the GCN superfamily of acyltransferases which lack conserved active site residues that participate in catalysis ApmA is the first reported AAC belonging to the left-handed -helix superfamily These enzymes are characterized by an essential active site histidine that acts as an active site base Here we show that ApmA confers broad-spectrum aminoglycoside resistance with a molecular mechanism that diverges from other ... More
The efficacy of aminoglycoside antibiotics is waning due to the acquisition of diverse resistance mechanisms by bacteria. Among the most prevalent are aminoglycoside acetyltransferases (AACs) that inactivate the antibiotics through acetyl coenzyme A-mediated modification. Most AACs are members of the GCN5 superfamily of acyltransferases which lack conserved active site residues that participate in catalysis. ApmA is the first reported AAC belonging to the left-handed β-helix superfamily. These enzymes are characterized by an essential active site histidine that acts as an active site base. Here we show that ApmA confers broad-spectrum aminoglycoside resistance with a molecular mechanism that diverges from other detoxifying left-handed β-helix superfamily enzymes and canonical GCN5 AACs. We find that the active site histidine plays different functions depending on the acetyl-accepting aminoglycoside substrate. This flexibility in the mechanism of a single enzyme underscores the plasticity of antibiotic resistance elements to co-opt protein catalysts in the evolution of drug detoxification. Less
This study aimed to identify inhibitors of the translocated intimin receptor Tir of enteropathogenic Escherichia coli EPEC EPEC is an intestinal pathogen that causes diarrhea and is a major health concern worldwide Because Tir is a key virulence factor involved in EPEC pathogenesis inhibiting its function is a potential strategy for controlling EPEC infections Virtual screening was applied to chemical libraries to search for compounds that inhibit Tir-mediated bacterial adherence to host cells Three sites were targeted using the cocrystal structure published earlier A selection of compounds was then assessed in a cell-based infection model and fluorescence microscopy assay The ... More
This study aimed to identify inhibitors of the translocated intimin receptor (Tir) of enteropathogenic Escherichia coli (EPEC). EPEC is an intestinal pathogen that causes diarrhea and is a major health concern worldwide. Because Tir is a key virulence factor involved in EPEC pathogenesis, inhibiting its function is a potential strategy for controlling EPEC infections. Virtual screening was applied to chemical libraries to search for compounds that inhibit Tir-mediated bacterial adherence to host cells. Three sites were targeted using the cocrystal structure published earlier. A selection of compounds was then assessed in a cell-based infection model and fluorescence microscopy assay. The results of this study provide a basis for further optimization and testing of Tir inhibitors as potential therapeutic agents for EPEC infections. Less
Transglutaminases TGases are a family of calcium-dependent enzymes primarily known for their ability to cross-link proteins Transglutaminase TG is one isozyme in this family whose role is multifaceted TG can act not only as a typical transamidase through its catalytic core but also as a G-protein via its GTP binding site These two discrete activities are tightly regulated by both environmental stimuli and redox reactions Ubiquitously expressed in humans TG has been implicated in numerous disease pathologies that require extensive investigation The catalytic activity of TG can be monitored through various mechanisms including hydrolysis transamidation or cleavage of isopeptide bonds ... More
Transglutaminases (TGases) are a family of calcium-dependent enzymes primarily known for their ability to cross-link proteins. Transglutaminase 2 (TG2) is one isozyme in this family whose role is multifaceted. TG2 can act not only as a typical transamidase through its catalytic core but also as a G-protein via its GTP binding site. These two discrete activities are tightly regulated by both environmental stimuli and redox reactions. Ubiquitously expressed in humans, TG2 has been implicated in numerous disease pathologies that require extensive investigation. The catalytic activity of TG2 can be monitored through various mechanisms, including hydrolysis, transamidation, or cleavage of isopeptide bonds. Activity assays are required to monitor the activity of this isozyme not only for studying its transamidation reaction but also for validation of therapeutics designed to abolish this activity. Herein, we present the design, synthesis, and evaluation of a new TG2 activity substrate based on a previously optimized inhibitor scaffold. The substrate APH7 exhibits excellent affinity, selectivity, and reactivity with TG2 (KM = 3.0 μM). Furthermore, its application also allowed the discovery of unique hysteresis at play within the catalytic activity and inhibition reactivity of TG2. Less
We have adapted the cell painting assay developed by Carpenter and colleagues on cultured U OS cells to human spermatozoa In Sperm Cell Painting SCP we assemble an image-based quantitative fingerprint of the functional state of sperm We use this assay to gain insight into the mechanism of action of compounds that modify sperm function and as a platform for contraceptive discovery
The COVID- pandemic caused by severe acute respiratory syndrome coronavirus SARS-CoV- virus has made it clear that further development of antiviral therapies will be needed to combat additional SARS-CoV- variants or novel CoVs Here we describe small molecule inhibitors for SARS-CoV- Mac which counters ADP-ribosylation mediated innate immune responses The compounds inhibiting Mac were discovered through high-throughput screening HTS using a protein FRET-based competition assay and the best hit compound had an IC of M Three validated HTS hits have the same -amide- -methylester thiophene scaffold and the scaffold was selected for structure-activity relationship SAR studies through commercial and synthesized ... More
The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has made it clear that further development of antiviral therapies will be needed to combat additional SARS-CoV-2 variants or novel CoVs. Here, we describe small molecule inhibitors for SARS-CoV-2 Mac1, which counters ADP-ribosylation mediated innate immune responses. The compounds inhibiting Mac1 were discovered through high-throughput screening (HTS) using a protein FRET-based competition assay and the best hit compound had an IC50 of 14 µM. Three validated HTS hits have the same 2-amide-3-methylester thiophene scaffold and the scaffold was selected for structure-activity relationship (SAR) studies through commercial and synthesized analogs. We studied the compound binding mode in detail using X-ray crystallography and this allowed us to focus on specific features of the compound and design analogs. Compound 27 (MDOLL-0229) had an IC50 of 2.1 µM and was generally selective for CoV Mac1 proteins after profiling for activity against a panel of viral and human ADP-ribose binding proteins. The improved potency allowed testing of its effect on virus replication and indeed, 27 inhibited replication of a mouse hepatitis virus, a prototype CoV. Compound 27 is the first Mac1 targeted small molecule demonstrated to inhibit coronavirus replication in a cell model. This, together with its well-defined binding mode, makes 27 a good candidate for further hit/lead-optimization efforts. Less
Wastewater-based SARS-CoV- epidemiology WBE has proven as an excellent tool to monitor pandemic dynamics supporting individual testing strategies WBE can also be used as an early warning system for monitoring the emergence of novel pathogens or viral variants However for a timely transmission of results sophisticated sample logistics and analytics performed in decentralized laboratories close to the sampling sites are required Since multiple decentralized laboratories commonly use custom in-house workflows for sample purification and PCR-analysis comparative quality control of the analytical procedures is essential to report reliable and comparable results In this study we performed an interlaboratory comparison at laboratories ... More
Wastewater-based SARS-CoV-2 epidemiology (WBE) has proven as an excellent tool to monitor pandemic dynamics supporting individual testing strategies. WBE can also be used as an early warning system for monitoring the emergence of novel pathogens or viral variants. However, for a timely transmission of results, sophisticated sample logistics and analytics performed in decentralized laboratories close to the sampling sites are required. Since multiple decentralized laboratories commonly use custom in-house workflows for sample purification and PCR-analysis, comparative quality control of the analytical procedures is essential to report reliable and comparable results.In this study, we performed an interlaboratory comparison at laboratories specialized for PCR and high-throughput-sequencing (HTS)-based WBE analysis. Frozen reserve samples from low COVID-19 incidence periods were spiked with different inactivated authentic SARS-CoV-2 variants in graduated concentrations and ratios. Samples were sent to the participating laboratories for analysis using laboratory specific methods and the reported viral genome copy numbers and the detection of viral variants were compared with the expected values.Despite the different procedures, a high concordance regarding the SARS-CoV-2 PCR quantification could be achieved with low variation between the workflows. PCR-based genotyping was, in dependence of the underlying PCR-assay performance, able to predict the relative amount of variant specific substitutions even in samples with low spike-in amount. The identification of variants by HTS, however, required >100 copies/mL wastewater and had limited predictive value when analyzing at a genome coverage below 60%.This interlaboratory test demonstrates that despite different extraction and analysis methods, a high agreement of the SARS-CoV-2 genome copy equivalents could be achieved. Hence, decentralized SARS-CoV-2 wastewater monitoring is feasible to generate comparable analysis results. However, since not all assays detected the correct variant, prior evaluation of PCR and sequencing workflows as well as sustained quality control such as interlaboratory comparisons are mandatory for correct variant detection. Less
Single-cell analysis has clearly established itself in biology and biomedical fields as an invaluable tool that allows one to comprehensively understand the relationship between cells including their types states transitions trajectories and spatial position Scientific methods such as fluorescence labeling nanoscale super-resolution microscopy advances in single cell RNAseq and proteomics technologies provide more detailed information about biological processes which were not evident with the analysis of bulk material This new era of single-cell biology provides a better understanding of such complex biological systems as cancer inflammation immunity mechanism and aging processes and opens the door into the field of drug ... More
Single-cell analysis has clearly established itself in biology and biomedical fields as an invaluable tool that allows one to comprehensively understand the relationship between cells, including their types, states, transitions, trajectories, and spatial position. Scientific methods such as fluorescence labeling, nanoscale super-resolution microscopy, advances in single cell RNAseq and proteomics technologies, provide more detailed information about biological processes which were not evident with the analysis of bulk material. This new era of single-cell biology provides a better understanding of such complex biological systems as cancer, inflammation, immunity mechanism and aging processes, and opens the door into the field of drug response heterogeneity. The latest discoveries of cellular heterogeneity gives us an unique understanding of complex biological processes, such as disease mechanism, and will lead to new strategies for better and personalized treatment strategies. Recently, single-cell proteomics techniques that allow quantification of thousands of proteins from single mammalian cells have been introduced. Here we present an improved single-cell mass spectrometry-based proteomics platform called SCREEN (Single Cell pRotEomE aNalysis) for deep and high-throughput single-cell proteome coverage with high efficiency, less turnaround time and with an improved ability for protein quantitation across more cells than previously achieved. We applied this new platform to analyze the single-cell proteomic landscape under different drug treatment over time to uncover heterogeneity in cancer cell response, which for the first time, to our knowledge, has been achieved by mass spectrometry based analytical methods. We discuss challenges in single-cell proteomics, future improvements and general trends with the goal to encourage forthcoming technical developments. Less
We have used a cohort of human induced pluripotent stem cell hiPSC lines to develop a laboratory-based drug screening platform to predict variable drug responses of potential clinical relevance Our approach is based on the findings that hiPSC lines reflect the genetic identity of the donor and that pluripotent hiPSC lines express a broad repertoire of gene transcripts and proteins We demonstrate that a cohort of hiPSC lines from different donors can be screened efficiently in their pluripotent state using high-throughput cell painting assays allowing detection of variable phenotypic responses to a wide range of clinically approved drugs across multiple ... More
We have used a cohort of human induced pluripotent stem cell (hiPSC) lines to develop a laboratory-based drug screening platform to predict variable drug responses of potential clinical relevance. Our approach is based on the findings that hiPSC lines reflect the genetic identity of the donor and that pluripotent hiPSC lines express a broad repertoire of gene transcripts and proteins. We demonstrate that a cohort of hiPSC lines from different donors can be screened efficiently in their pluripotent state using high-throughput cell painting assays, allowing detection of variable phenotypic responses to a wide range of clinically approved drugs, across multiple disease areas. Furthermore, we provide information on mechanisms of drug-cell interactions underlying the observed variable responses by using quantitative proteomic analysis to compare sets of hiPSC lines that had been stratified objectively using cell painting data. We propose that information derived from comparative drug screening using curated libraries of hiPSC lines can help to increase the success rate of drug development pipelines and improve the delivery of safe new drugs suitable for a broader ethnic and gender diversity within human populations. Less
Training artificial intelligence AI systems to perform autonomous experiments would vastly increase the throughput of microbiology however few microbes have large enough datasets for training such a system In the present study we introduce BacterAI an automated science platform that maps microbial metabolism but requires no prior knowledge BacterAI learns by converting scientific questions into simple games that it plays with laboratory robots The agent then distils its findings into logical rules that can be interpreted by human scientists We use BacterAI to learn the amino acid requirements for two oral streptococci Streptococcus gordonii and Streptococcus sanguinis We then show ... More
Training artificial intelligence (AI) systems to perform autonomous experiments would vastly increase the throughput of microbiology; however, few microbes have large enough datasets for training such a system. In the present study, we introduce BacterAI, an automated science platform that maps microbial metabolism but requires no prior knowledge. BacterAI learns by converting scientific questions into simple games that it plays with laboratory robots. The agent then distils its findings into logical rules that can be interpreted by human scientists. We use BacterAI to learn the amino acid requirements for two oral streptococci: Streptococcus gordonii and Streptococcus sanguinis. We then show how transfer learning can accelerate BacterAI when investigating new environments or larger media with up to 39 ingredients. Scientific gameplay and BacterAI enable the unbiased, autonomous study of organisms for which no training data exist. Less
A rare coding variant in PLC P R expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's disease LOAD and therefore activation of wild-type PLC has been suggested as a potential therapeutic target for the prevention and treatment of LOAD Additionally PLC has been associated with other diseases such as cancer and some autoimmune disorders where mutations with much greater increases in PLC activity have been identified Here pharmacological inhibition may provide a therapeutic effect In order to facilitate our ... More
A rare coding variant in PLCγ2 (P522R) expressed in microglia induces a mild activation of enzymatic activity when compared to wild-type. This mutation is reported to be protective against the cognitive decline associated with late-onset Alzheimer's disease (LOAD) and therefore, activation of wild-type PLCγ2 has been suggested as a potential therapeutic target for the prevention and treatment of LOAD. Additionally, PLCγ2 has been associated with other diseases such as cancer and some autoimmune disorders where mutations with much greater increases in PLCγ2 activity have been identified. Here, pharmacological inhibition may provide a therapeutic effect. In order to facilitate our investigation of the activity of PLCγ2, we developed an optimized fluorogenic substrate to monitor enzymatic activity in aqueous solution. This was accomplished by first exploring the spectral properties of various “turn-on” fluorophores. The most promising turn-on fluorophore was incorporated into a water-soluble PLCγ2 reporter substrate, which we named C8CF3-coumarin. The ability of PLCγ2 to enzymatically process C8CF3-coumarin was confirmed, and the kinetics of the reaction were determined. Reaction conditions were optimized to identify small molecule activators, and a pilot screen of the Library of Pharmacologically Active Compounds 1280 (LOPAC1280) was performed with the goal of identifying small molecule activators of PLCγ2. The optimized screening conditions allowed identification of potential PLCγ2 activators and inhibitors, thus demonstrating the feasibility of this approach for high-throughput screening. Less
Ubiquitination is a complex and reversible protein post-translational modification in which the subsequent action of enzymes belonging to three different families broadly referred to as E E and E results in the covalent linking of ubiquitin to a target protein While this linkage is canonically an isopeptide bond between the C-terminus of ubiquitin and the lysine residue of the target protein Ser Thr and Tyr can also be susceptible to ubiquitination through an oxyester bond Once ubiquitinated multiple units of ubiquitin can be attached to the initial ubiquitin thus extending it to a chain of ubiquitins Ubiquitination regulates multiple cellular ... More
Ubiquitination is a complex and reversible protein post-translational modification in which the subsequent action of enzymes belonging to three different families, broadly referred to as E1, E2 and E3, results in the covalent linking of ubiquitin to a target protein. While this linkage is canonically an isopeptide bond between the C-terminus of ubiquitin and the lysine residue of the target protein, Ser, Thr, and Tyr can also be susceptible to ubiquitination through an oxyester bond. Once ubiquitinated, multiple units of ubiquitin can be attached to the initial ubiquitin thus extending it to a chain of ubiquitins. Ubiquitination regulates multiple cellular processes, but it is best known as a modification that targets proteins for proteasomal degradation following the formation poly-ubiquitin chains linked through lysine 48 or 63 of ubiquitin. Dysregulation of ubiquitination has been associated with multiple types of cancer and efforts have been carried out to develop technologies that lead to the identification of inhibitors of the enzymes involved in the ubiquitination cascade. Herein, we present the development of a FRET-based assay that allows us to monitor auto-ubiquitination of DTX3L, a RING-type E3 ubiquitin ligase. Our method shows a robust signal window with a robust average Z’ factor of 0.76. From a validatory screening experiment we have identified the first molecules that inhibit DTX3L with potencies in the low micromolar range. Additionally, we have expanded the system to study deubiquitinases such as USP28 that lead to reduction of FRET due to hydrolysis of fluorescent poly-Ub chains. Less
Analyzing proteins from single cells by tandem mass spectrometry MS has recently become technically feasible While such analysis has the potential to accurately quantify thousands of proteins across thousands of single cells the accuracy and reproducibility of the results may be undermined by numerous factors affecting experimental design sample preparation data acquisition and data analysis We expect that broadly accepted community guidelines and standardized metrics will enhance rigor data quality and alignment between laboratories Here we propose best practices quality controls and data-reporting recommendations to assist in the broad adoption of reliable quantitative workflows for single-cell proteomics
Exonucleases are essential enzymes that remove nucleotides from free DNA ends during DNA replication DNA repair and telomere maintenance Due to their essential role they are potential targets for novel anticancer and antimicrobial drugs but have so far been little exploited Here we present a simple and versatile real-time exonuclease assay based on -aminopurine an intrinsically fluorescent nucleotide that is quenched by neighboring bases when embedded in DNA We show that our assay is applicable to different eukaryotic and bacterial exonucleases acting on both and DNA ends over a wide range of protein activities and suitable for a high-throughput inhibitor ... More
Exonucleases are essential enzymes that remove nucleotides from free DNA ends during DNA replication, DNA repair, and telomere maintenance. Due to their essential role, they are potential targets for novel anticancer and antimicrobial drugs but have so far been little exploited. Here, we present a simple and versatile real-time exonuclease assay based on 2-aminopurine, an intrinsically fluorescent nucleotide that is quenched by neighboring bases when embedded in DNA. We show that our assay is applicable to different eukaryotic and bacterial exonucleases acting on both 3′ and 5′ DNA ends over a wide range of protein activities and suitable for a high-throughput inhibitor screening campaign. Using our assay, we discover a novel inhibitor of the Mycobacterium tuberculosis PHP-exonuclease that is part of the replicative DNA polymerase DnaE1. Hence, our novel assay will be a useful tool for high-throughput screening for novel exonuclease inhibitors that may interfere with DNA replication or DNA maintenance. Less
This high-throughput protocol details the steps to extract protein from Gram-negative bacteria Gram-positive bacteria or non-filamentous fungi in -well plate format for quantitative proteomic workflows This protocol uses a bench-top automated liquid dispenser but the volumes and times also apply to manual and multi-channel pipetter use This protocol is designed for lab-based culture conditions and synthetic community experiments where complex sample matrices are minimized Additional sample preservation and or protein extraction methods may be required for environmental samples e g feces soil to minimize protein degradation and maintain sample integrity
The recent discovery of comammox complete ammonia oxidation Nitrospira has upended the long-held nitrification paradigm Although comammox Nitrospira have been identified in wastewater treatment systems the conditions for their dominance over canonical ammonia oxidizers remain unclear Here we report the dominance of comammox Nitrospira in a moving bed biofilm reactor MBBR fed with synthetic mainstream wastewater Integrated S rRNA gene amplicon sequencing fluorescence in situ hybridization FISH and metagenomic sequencing methods demonstrated the selective enrichment of comammox bacteria when the MBBR was operated at a dissolved oxygen DO concentration above mg O L The dominance of comammox Nitrospira over canonical ... More
The recent discovery of comammox (complete ammonia oxidation) Nitrospira has upended the long-held nitrification paradigm. Although comammox Nitrospira have been identified in wastewater treatment systems, the conditions for their dominance over canonical ammonia oxidizers remain unclear. Here, we report the dominance of comammox Nitrospira in a moving bed biofilm reactor (MBBR) fed with synthetic mainstream wastewater. Integrated 16S rRNA gene amplicon sequencing, fluorescence in situ hybridization (FISH), and metagenomic sequencing methods demonstrated the selective enrichment of comammox bacteria when the MBBR was operated at a dissolved oxygen (DO) concentration above 6 mg O2/L. The dominance of comammox Nitrospira over canonical ammonia oxidizers (i.e., Nitrosomonas) was attributed to the low residual ammonium concentration (0.02–0.52 mg N/L) formed in the high-DO MBBR. Two clade A comammox Nitrospira were identified, which are phylogenetically close to Candidatus Nitrospira nitrosa. Interestingly, cryosectioning-FISH showed these two comammox species spatially distributed on the surface of the biofilm. Moreover, the ammonia-oxidizing activity of comammox Nitrospira-dominated biofilms was susceptible to the oxygen supply, which dropped by half with the DO concentration decrease from 6 to 2 mg O2/L. These features collectively suggest a low apparent oxygen affinity for the comammox Nitrospira-dominated biofilms in the high-DO nitrifying MBBR. Less
Polyurethane-based hydrogels are relatively inexpensive and mechanically robust biomaterials with ideal properties for various applications including drug delivery prosthetics implant coatings soft robotics and tissue engineering In this report we present a simple method for synthesizing and casting biocompatible polyurethane-poly ethylene glycol PU-PEG hydrogels with tunable mechanical properties non-fouling characteristics and sustained tolerability as an implantable material or coating The hydrogels are synthesized via a simple one-pot method using commercially available precursors and low toxicity solvents and reagents yielding a consistent and biocompatible gel platform primed for long-term biomaterial applications The mechanical and physical properties of the gels are easily ... More
Polyurethane-based hydrogels are relatively inexpensive and mechanically robust biomaterials with ideal properties for various applications, including drug delivery, prosthetics, implant coatings, soft robotics, and tissue engineering. In this report, we present a simple method for synthesizing and casting biocompatible polyurethane-poly(ethylene glycol) (PU-PEG) hydrogels with tunable mechanical properties, non-fouling characteristics, and sustained tolerability as an implantable material or coating. The hydrogels are synthesized via a simple one-pot method using commercially available precursors and low toxicity solvents and reagents, yielding a consistent and biocompatible gel platform primed for long-term biomaterial applications. The mechanical and physical properties of the gels are easily controlled by varying the curing concentration, producing networks with complex shear moduli of 0.82 kPa – 190 kPa, similar to a range of human soft tissues. When evaluated against a mechanically-matched PDMS formulation the PU-PEG hydrogels demonstrated favorable non-fouling characteristics including comparable adsorption of plasma proteins (albumin and fibrinogen) and significantly reduced cellular adhesion. Moreover, preliminary murine implant studies reveal a mild foreign body response after 41 days. Due to the tunable mechanical properties, excellent biocompatibility, and sustained in vivo tolerability of these hydrogels, we propose that this method offers a simplified platform for fabricating soft PU-based biomaterials for a variety of applications. Less
Clonogenic assays evaluate the ability of single cells to proliferate and form colonies This process approximates the regrowth and recurrence of tumors after treatment with radiation or chemotherapy and thereby provides a drug discovery platform for compounds that block this process However because of their labor-intensive and cumbersome nature adapting canonical clonogenic assays for high throughput screening HTS has been challenging We overcame these barriers by developing an integrated system that automates cell- and liquid-handling irradiation dosimetry drug administration and incubation Further we developed a fluorescent live-cell based automated colony scoring methodology that identifies and counts colonies precisely based upon ... More
Clonogenic assays evaluate the ability of single cells to proliferate and form colonies. This process approximates the regrowth and recurrence of tumors after treatment with radiation or chemotherapy, and thereby provides a drug discovery platform for compounds that block this process. However, because of their labor-intensive and cumbersome nature, adapting canonical clonogenic assays for high throughput screening (HTS) has been challenging. We overcame these barriers by developing an integrated system that automates cell- and liquid-handling, irradiation, dosimetry, drug administration, and incubation. Further, we developed a fluorescent live-cell based automated colony scoring methodology that identifies and counts colonies precisely based upon actual nuclei number rather than colony area, thereby eliminating errors in colony counts caused by radiation induced changes in colony morphology. We identified 13 cell lines from 7 cancer types, where radiation is a standard treatment module, that exhibit identical radiation and chemoradiation response regardless of well format and are amenable to miniaturization into small-well HTS formats. We performed pilot screens through a 1584 compound NCI Diversity Set library using two cell lines representing different cancer indications. Radiation modulators identified in the pilot screens were validated in traditional clonogenic assays, providing proof-of-concept for the screen. The integrated methodology, hereafter ‘clonogenic HTS’, exhibits excellent robustness (Z’ values >0.5) and shows high reproducibility (>95%). We propose that clonogenic HTS we developed can function as a drug discovery platform to identify compounds that inhibit tumor regrowth following radiation therapy, to identify new efficacious pair-wise combinations of known oncologic therapies, or to identify novel modulators of approved therapies. Less
Advancements in technology and communication have revolutionised the twenty-first century with the introduction of mobile phones and smartphones These phones are known to be platforms harbouring microbes with recent research shedding light on the abundance and broad spectrum of organisms they harbour Mobile phone use in the community and in professional sectors including health care settings is a potential source of microbial dissemination To identify the diversity of microbial genetic signature present on mobile phones owned by hospital medical staff Twenty-six mobile phones of health care staff were swabbed DNA extraction for downstream next generation sequencing shotgun metagenomic microbial profiling ... More
Advancements in technology and communication have revolutionised the twenty-first century with the introduction of mobile phones and smartphones. These phones are known to be platforms harbouring microbes with recent research shedding light on the abundance and broad spectrum of organisms they harbour. Mobile phone use in the community and in professional sectors including health care settings is a potential source of microbial dissemination. To identify the diversity of microbial genetic signature present on mobile phones owned by hospital medical staff. Twenty-six mobile phones of health care staff were swabbed. DNA extraction for downstream next generation sequencing shotgun metagenomic microbial profiling was performed. Survey questionnaires were handed to the staff to collect information on mobile phone usage and users’ behaviours. Each of the 26 mobile phones of this study was contaminated with microbes with the detection of antibiotic resistance and virulent factors. Taken together the sum of microbes and genes added together across all 26 mobile phones totalised 11,163 organisms (5714 bacteria, 675 fungi, 93 protists, 228 viruses, 4453 bacteriophages) and 2096 genes coding for antibiotic resistance and virulent factors. The survey of medical staff showed that 46% (12/26) of the participants used their mobile phones in the bathroom. Mobile phones are vectors of microbes and can contribute to microbial dissemination and nosocomial diseases worldwide. As fomites, mobile phones that are not decontaminated may pose serious risks for public health and biosecurity. Less
The CRISPR-Cas type V-I is a family of Cas i-containing programmable nuclease systems guided by a short crRNA without requirement for a tracrRNA Here we present an engineered Type V-I CRISPR system Cas i ABR- which utilizes a tracr-less guide RNA The compact Cas i effector is capable of self-processing pre-crRNA and cleaving dsDNA targets which facilitates versatile delivery options and multiplexing respectively We apply an unbiased mutational scanning approach to enhance initially low editing activity of Cas i The engineered variant ABR- exhibits broad genome editing capability in human cell lines primary T cells and CD hematopoietic stem and ... More
The CRISPR-Cas type V-I is a family of Cas12i-containing programmable nuclease systems guided by a short crRNA without requirement for a tracrRNA. Here we present an engineered Type V-I CRISPR system (Cas12i), ABR-001, which utilizes a tracr-less guide RNA. The compact Cas12i effector is capable of self-processing pre-crRNA and cleaving dsDNA targets, which facilitates versatile delivery options and multiplexing, respectively. We apply an unbiased mutational scanning approach to enhance initially low editing activity of Cas12i2. The engineered variant, ABR-001, exhibits broad genome editing capability in human cell lines, primary T cells, and CD34+ hematopoietic stem and progenitor cells, with both robust efficiency and high specificity. In addition, ABR-001 achieves a high level of genome editing when delivered via AAV vector to HEK293T cells. This work establishes ABR-001 as a versatile, specific, and high-performance platform for ex vivo and in vivo gene therapy. Less
The dysregulation of the PRC complex plays a key role in lineage plasticity in prostate cancer and may be required to maintain neuroendocrine phenotype CBX a key component of the canonical PRC complex is an epigenetic reader recognizing trimethylated lysine on histone H K me and is overexpressed in metastatic neuroendocrine prostate cancer We implemented a screening strategy using nucleosome substrates to identify inhibitors of CBX binding to chromatin Construct design and phosphorylation state of CBX were critical for successful implementation and execution of an HTS library screen A rigorous screening funnel including counter and selectivity assays allowed us to ... More
The dysregulation of the PRC1/2 complex plays a key role in lineage plasticity in prostate cancer and may be required to maintain neuroendocrine phenotype. [1] CBX2, a key component of the canonical PRC1 complex, is an epigenetic reader, recognizing trimethylated lysine on histone 3 (H3K27me3) [2] and is overexpressed in metastatic neuroendocrine prostate cancer. [3,4] We implemented a screening strategy using nucleosome substrates to identify inhibitors of CBX2 binding to chromatin. Construct design and phosphorylation state of CBX2 were critical for successful implementation and execution of an HTS library screen. A rigorous screening funnel including counter and selectivity assays allowed us to quickly focus on true positive hit matter. Two distinct non-peptide-like chemotypes were identified and confirmed in orthogonal biochemical and biophysical assays demonstrating disruption of CBX2 binding to nucleosomes and direct binding to purified CBX2, respectively. Less
In the last decade zebrafish have accompanied the mouse as a robust animal model for cancer research The possibility of screening small-molecule inhibitors in a large number of zebrafish embryos makes this model particularly valuable However the dynamic visualization of fluorescently labeled tumor cells needs to be complemented by a more sensitive easy and rapid mode for evaluating tumor growth in vivo to enable high-throughput screening of clinically relevant drugs In this study we proposed and validated a pre-clinical screening model for drug discovery by utilizing bioluminescence as our readout for the determination of transplanted cancer cell growth and inhibition ... More
In the last decade, zebrafish have accompanied the mouse as a robust animal model for cancer research. The possibility of screening small-molecule inhibitors in a large number of zebrafish embryos makes this model particularly valuable. However, the dynamic visualization of fluorescently labeled tumor cells needs to be complemented by a more sensitive, easy, and rapid mode for evaluating tumor growth in vivo to enable high-throughput screening of clinically relevant drugs. In this study we proposed and validated a pre-clinical screening model for drug discovery by utilizing bioluminescence as our readout for the determination of transplanted cancer cell growth and inhibition in zebrafish embryos. For this purpose, we used NanoLuc luciferase, which ensured rapid cancer cell growth quantification in vivo with high sensitivity and low background when compared to conventional fluorescence measurements. This allowed us large-scale evaluation of in vivo drug responses of 180 kinase inhibitors in zebrafish. Our bioluminescent screening platform could facilitate identification of new small-molecules for targeted cancer therapy as well as for drug repurposing. Less
Gut inflammation directly impacts the growth and stability of commensal gut microbes and can lead to long-lasting changes in microbiota composition that can prolong or exacerbate disease states While mouse models are used extensively to investigate the interplay between microbes and the inflamed state the paucity of cultured mouse gut microbes has hindered efforts to determine causal relationships To address this issue we are assembling the Collection of Inflammation-Associated Mouse Intestinal Bacteria CIAMIB The initial release of this collection comprises isolates of unique bacterial species covering phyla and containing previously uncultivated isolates including novel family and novel genera The collection ... More
Gut inflammation directly impacts the growth and stability of commensal gut microbes and can lead to long-lasting changes in microbiota composition that can prolong or exacerbate disease states. While mouse models are used extensively to investigate the interplay between microbes and the inflamed state, the paucity of cultured mouse gut microbes has hindered efforts to determine causal relationships. To address this issue, we are assembling the Collection of Inflammation-Associated Mouse Intestinal Bacteria (CIAMIB). The initial release of this collection comprises 41 isolates of 39 unique bacterial species, covering 4 phyla and containing 10 previously uncultivated isolates, including 1 novel family and 7 novel genera. The collection significantly expands the number of available Muribaculaceae, Lachnospiraceae, and Coriobacteriaceae isolates and includes microbes from genera associated with inflammation, such as Prevotella and Klebsiella. We characterized the growth of CIAMIB isolates across a diverse range of nutritional conditions and predicted their metabolic potential and anaerobic fermentation capacity based on the genomes of these isolates. We also provide the first metabolic analysis of species within the genus Adlercreutzia, revealing these representatives to be nitrate-reducing and severely restricted in their ability to grow on carbohydrates. CIAMIB isolates are fully sequenced and available to the scientific community as a powerful tool to study host-microbiota interactions. Less
The emergence of several zoonotic viruses in the last twenty years especially the pandemic outbreak of SARS-CoV- has exposed a dearth of antiviral drug therapies for viruses with pandemic potential Developing a diverse drug portfolio will be critical for our ability to rapidly respond to novel coronaviruses CoVs and other viruses with pandemic potential Here we focus on the SARS-CoV- conserved macrodomain Mac a small domain of non-structural protein nsp Mac is an ADP-ribosylhydrolase that cleaves mono-ADP-ribose MAR from target proteins protects the virus from the anti-viral effects of host ADP-ribosyltransferases and is critical for the replication and pathogenesis of ... More
The emergence of several zoonotic viruses in the last twenty years, especially the pandemic outbreak of SARS-CoV-2, has exposed a dearth of antiviral drug therapies for viruses with pandemic potential. Developing a diverse drug portfolio will be critical for our ability to rapidly respond to novel coronaviruses (CoVs) and other viruses with pandemic potential. Here we focus on the SARS-CoV-2 conserved macrodomain (Mac1), a small domain of non-structural protein 3 (nsp3). Mac1 is an ADP-ribosylhydrolase that cleaves mono-ADP-ribose (MAR) from target proteins, protects the virus from the anti-viral effects of host ADP-ribosyltransferases, and is critical for the replication and pathogenesis of CoVs. In this study, a luminescent-based high-throughput assay was used to screen ∼38,000 small molecules for those that could inhibit Mac1-ADP-ribose binding. We identified 5 compounds amongst 3 chemotypes that inhibit SARS-CoV-2 Mac1-ADP-ribose binding in multiple assays with IC50 values less than 100µM, inhibit ADP-ribosylhydrolase activity, and have evidence of direct Mac1 binding. These chemotypes are strong candidates for further derivatization into highly effective Mac1 inhibitors. Less
Tousled-like kinases TLKs are nuclear serine-threonine kinases essential for genome maintenance and proper cell division in animals and plants A major function of TLKs is to phosphorylate the histone chaperone proteins ASF a and ASF b to facilitate DNA replication-coupled nucleosome assembly but how TLKs selectively target these critical substrates is unknown Here we show that TLK selectivity towards ASF substrates is achieved in two ways First the TLK catalytic domain recognizes consensus phosphorylation site motifs in the ASF C-terminal tail Second a short sequence at the TLK N-terminus docks onto the ASF a globular N-terminal domain in a manner ... More
Tousled-like kinases (TLKs) are nuclear serine-threonine kinases essential for genome maintenance and proper cell division in animals and plants. A major function of TLKs is to phosphorylate the histone chaperone proteins ASF1a and ASF1b to facilitate DNA replication-coupled nucleosome assembly, but how TLKs selectively target these critical substrates is unknown. Here, we show that TLK2 selectivity towards ASF1 substrates is achieved in two ways. First, the TLK2 catalytic domain recognizes consensus phosphorylation site motifs in the ASF1 C-terminal tail. Second, a short sequence at the TLK2 N-terminus docks onto the ASF1a globular N-terminal domain in a manner that mimics its histone H3 client. Disrupting either catalytic or non-catalytic interactions through mutagenesis hampers ASF1 phosphorylation by TLK2 and cell growth. Our results suggest that the stringent selectivity of TLKs for ASF1 is enforced by an unusual interaction mode involving mutual recognition of a short sequence motifs by both kinase and substrate. Less
Identification of selective deubiquitinase DUB inhibitors is critical for probe development to further understand and explore DUB biological function Here we detail the optimization and deployment of an in vitro fluorogenic ubiquitin-rhodamine assay to conduct high-throughput screening of a small molecule library against a panel of DUBs In screening the compound library against multiple DUBs in parallel we describe an approach for identifying selective DUB inhibitors and provide a roadmap for enabling selective DUB inhibitor discovery
Deubiquitinating enzymes DUBs are a class of isopeptidases that regulate ubiquitin dynamics through catalytic cleavage of ubiquitin from protein substrates and ubiquitin precursors Despite growing interest in DUB biological function and potential as therapeutic targets few selective small-molecule inhibitors and no approved drugs currently exist To identify chemical scaffolds targeting specific DUBs and establish a broader framework for future inhibitor development across the gene family we performed high-throughput screening of a chemically diverse small-molecule library against eight different DUBs spanning three well-characterized DUB families Promising hit compounds were validated in a series of counter-screens and orthogonal assays as well as ... More
Deubiquitinating enzymes (DUBs) are a class of isopeptidases that regulate ubiquitin dynamics through catalytic cleavage of ubiquitin from protein substrates and ubiquitin precursors. Despite growing interest in DUB biological function and potential as therapeutic targets, few selective small-molecule inhibitors and no approved drugs currently exist. To identify chemical scaffolds targeting specific DUBs and establish a broader framework for future inhibitor development across the gene family, we performed high-throughput screening of a chemically diverse small-molecule library against eight different DUBs, spanning three well-characterized DUB families. Promising hit compounds were validated in a series of counter-screens and orthogonal assays, as well as further assessed for selectivity across expanded panels of DUBs. Through these efforts, we have identified multiple highly selective DUB inhibitors and developed a roadmap for rapidly identifying and validating selective inhibitors of related enzymes. Less
The cancer-associated fibroblast CAF marker podoplanin PDPN is generally correlated with poor clinical outcomes in cancer patients and thus represents a promising therapeutic target Despite its biomedical relevance basic aspects of PDPN biology such as its cellular functions and cell surface ligands remain poorly uncharacterized thus challenging drug development Here we utilize a high throughput platform to elucidate the PDPN cell surface interactome and uncover the neutrophil protein CD as a new binding partner Quantitative proteomics analysis of the CAF phosphoproteome reveals a role for PDPN in cell signaling growth and actomyosin contractility among other processes Moreover cellular assays demonstrate ... More
The cancer-associated fibroblast (CAF) marker podoplanin (PDPN) is generally correlated with poor clinical outcomes in cancer patients and thus represents a promising therapeutic target. Despite its biomedical relevance, basic aspects of PDPN biology such as its cellular functions and cell surface ligands remain poorly uncharacterized, thus challenging drug development. Here, we utilize a high throughput platform to elucidate the PDPN cell surface interactome, and uncover the neutrophil protein CD177 as a new binding partner. Quantitative proteomics analysis of the CAF phosphoproteome reveals a role for PDPN in cell signaling, growth and actomyosin contractility, among other processes. Moreover, cellular assays demonstrate that CD177 is a functional antagonist, recapitulating the phenotype observed in PDPN-deficient CAFs. In sum, starting from the unbiased elucidation of the PDPN co-receptome, our work provides insights into PDPN functions and reveals the PDPN/CD177 axis as a possible modulator of fibroblast physiology in the tumor microenvironment. Less
Ongoing antibiotic drug discovery is vital as antimicrobial resistance continues to be a significant issue faced in the clinic Natural products have long been a highly productive source to mine for new antimicrobials While it has been challenging to discover new and unique antimicrobial natural products numerous drugs have been derived from studying how natural products function as secondary metabolites Previous studies suggested that screening natural product extract fraction libraries for antimicrobials can be more productive than screening crude extracts alone These studies from large industrial enterprises are generally not directly portable to an academic setting due to significant infrastructure ... More
Ongoing antibiotic drug discovery is vital as antimicrobial resistance continues to be a significant issue faced in the clinic. Natural products have long been a highly productive source to mine for new antimicrobials. While it has been challenging to discover new and unique antimicrobial natural products, numerous drugs have been derived from studying how natural products function as secondary metabolites. Previous studies suggested that screening natural product extract fraction libraries for antimicrobials can be more productive than screening crude extracts alone. These studies from large industrial enterprises are generally not directly portable to an academic setting due to significant infrastructure costs. We developed a screening platform consisting of low pressure reversed-phase chromatographic separation of methanolic extracts of bacteria and fungi to generate a prefractionated natural product library. This platform is suitable for academic labs to screen for antimicrobial compounds. A large growth inhibitor screen against multiple pathogens and lab strains of microbes was conducted to assess the validity of the advantages of screening fraction libraries versus crude extract libraries and to search for potential new drug-like compounds. Hits were investigated for reproducibility, isolated, and purified. One compound was discovered in an antifungal screen which may be a novel lipopeptide. Less
Many biological systems are composed of diverse single cells This diversity necessitates functional and molecular single-cell analysis Single-cell protein analysis has long relied on affinity reagents but emerging mass-spectrometry methods either label-free or multiplexed have enabled quantifying proteins per cell while simultaneously increasing the specificity of protein quantification Here we describe the Single Cell ProtEomics SCoPE protocol which uses an isobaric carrier to enhance peptide sequence identification Single cells are isolated by FACS or CellenONE into multiwell plates and lysed by Minimal ProteOmic sample Preparation mPOP and their peptides labeled by isobaric mass tags TMT or TMTpro for multiplexed analysis ... More
Many biological systems are composed of diverse single cells. This diversity necessitates functional and molecular single-cell analysis. Single-cell protein analysis has long relied on affinity reagents, but emerging mass-spectrometry methods (either label-free or multiplexed) have enabled quantifying >1,000 proteins per cell while simultaneously increasing the specificity of protein quantification. Here we describe the Single Cell ProtEomics (SCoPE2) protocol, which uses an isobaric carrier to enhance peptide sequence identification. Single cells are isolated by FACS or CellenONE into multiwell plates and lysed by Minimal ProteOmic sample Preparation (mPOP), and their peptides labeled by isobaric mass tags (TMT or TMTpro) for multiplexed analysis. SCoPE2 affords a cost-effective single-cell protein quantification that can be fully automated using widely available equipment and scaled to thousands of single cells. SCoPE2 uses inexpensive reagents and is applicable to any sample that can be processed to a single-cell suspension. The SCoPE2 workflow allows analyzing ~200 single cells per 24 h using only standard commercial equipment. We emphasize experimental steps and benchmarks required for achieving quantitative protein analysis. Less
Determinants of protective immunity against severe acute respiratory syndrome coronavirus SARS-CoV- infection require the development of well-standardized reproducible antibody assays This need has led to the emergence of a variety of neutralization assays Head-to-head evaluation of different SARS-CoV- neutralization platforms could facilitate comparisons across studies and laboratories Five neutralization assays were compared using plasma samples from convalescent individuals with mild to moderate coronavirus disease COVID- four cell-based systems using either live recombinant SARS-CoV- or pseudotyped viral particles created with lentivirus LV or vesicular stomatitis virus VSV packaging and one surrogate enzyme-linked immunosorbent assay ELISA -based test that measures inhibition of ... More
Determinants of protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection require the development of well-standardized, reproducible antibody assays. This need has led to the emergence of a variety of neutralization assays. Head-to-head evaluation of different SARS-CoV-2 neutralization platforms could facilitate comparisons across studies and laboratories. Five neutralization assays were compared using 40 plasma samples from convalescent individuals with mild to moderate coronavirus disease 2019 (COVID-19): four cell-based systems using either live recombinant SARS-CoV-2 or pseudotyped viral particles created with lentivirus (LV) or vesicular stomatitis virus (VSV) packaging and one surrogate enzyme-linked immunosorbent assay (ELISA)-based test that measures inhibition of the spike protein receptor binding domain (RBD) binding its receptor human angiotensin converting enzyme 2 (hACE2). Vero cells, Vero E6 cells, HEK293T cells expressing hACE2, and TZM-bl cells expressing hACE2 and transmembrane serine protease 2 were tested. All cell-based assays showed 50% neutralizing dilution (ND50) geometric mean titers (GMTs) that were highly correlated (Pearson r = 0.81 to 0.89) and ranged within 3.4-fold. The live virus assay and LV pseudovirus assays with HEK293T/hACE2 cells showed very similar mean titers, 141 and 178, respectively. ND50 titers positively correlated with plasma IgG targeting SARS-CoV-2 spike protein and RBD (r = 0.63 to 0.89), but moderately correlated with nucleoprotein IgG (r = 0.46 to 0.73). ND80 GMTs mirrored ND50 data and showed similar correlation between assays and with IgG concentrations. The VSV pseudovirus assay and LV pseudovirus assay with HEK293T/hACE2 cells in low- and high-throughput versions were calibrated against the WHO SARS-CoV-2 IgG standard. High concordance between the outcomes of cell-based assays with live and pseudotyped virions enables valid cross-study comparison using these platforms. Less
Cell embedment into a solid support matrix is considered essential for the culture of intestinal epithelial organoids and tumoroids but this technique presents challenges that impede scalable culture expansion experimental manipulation high-throughput screening and diagnostic applications We have developed a low-viscosity matrix LVM suspension culture method that enables efficient establishment and propagation of organoids and tumoroids from the human large intestine Organoids and tumoroids cultured in LVM suspension recapitulate the morphological development observed in solid matrices with tumoroids reflecting the histological features and genetic heterogeneity of primary colorectal cancers We demonstrate the utility of LVM suspension culture for organoid and ... More
Cell embedment into a solid support matrix is considered essential for the culture of intestinal epithelial organoids and tumoroids, but this technique presents challenges that impede scalable culture expansion, experimental manipulation, high-throughput screening and diagnostic applications. We have developed a low-viscosity matrix (LVM) suspension culture method that enables efficient establishment and propagation of organoids and tumoroids from the human large intestine. Organoids and tumoroids cultured in LVM suspension recapitulate the morphological development observed in solid matrices, with tumoroids reflecting the histological features and genetic heterogeneity of primary colorectal cancers. We demonstrate the utility of LVM suspension culture for organoid and tumoroid bioreactor applications and biobanking, as well as tumoroid high-throughput drug sensitivity testing. These methods provide opportunities for the study and use of patient-derived organoids and tumoroids from the large intestine. Less
In humans epidermal melanocytes are responsible for skin pigmentation defence against ultraviolet radiation and the deadliest common skin cancer melanoma Although there is substantial overlap in melanocyte development pathways between different model organisms species-dependent differences are frequent and the conservation of these processes in human skin remains unresolved Here we used a single-cell enrichment and RNA-sequencing pipeline to study human epidermal melanocytes directly from the skin capturing transcriptomes across different anatomical sites developmental age sexes and multiple skin tones We uncovered subpopulations of melanocytes that exhibit anatomical site-specific enrichment that occurs during gestation and persists through adulthood The transcriptional signature ... More
In humans, epidermal melanocytes are responsible for skin pigmentation, defence against ultraviolet radiation and the deadliest common skin cancer, melanoma. Although there is substantial overlap in melanocyte development pathways between different model organisms, species-dependent differences are frequent and the conservation of these processes in human skin remains unresolved. Here, we used a single-cell enrichment and RNA-sequencing pipeline to study human epidermal melanocytes directly from the skin, capturing transcriptomes across different anatomical sites, developmental age, sexes and multiple skin tones. We uncovered subpopulations of melanocytes that exhibit anatomical site-specific enrichment that occurs during gestation and persists through adulthood. The transcriptional signature of the volar-enriched subpopulation is retained in acral melanomas. Furthermore, we identified human melanocyte differentiation transcriptional programs that are distinct from gene signatures generated from model systems. Finally, we used these programs to define patterns of dedifferentiation that are predictive of melanoma prognosis and response to immune checkpoint inhibitor therapy. Less
In bacteria trans-translation is the major quality control system for rescuing stalled ribosomes It is mediated by tmRNA a hybrid RNA with properties of both a tRNA and a mRNA and the small protein SmpB Because trans-translation is absent in eukaryotes but necessary for bacterial fitness or survival it is a promising target for the development of novel antibiotics To facilitate screening of chemical libraries various reliable in vitro and in vivo systems have been created for assessing trans-translational activity However the aim of the current work was to permit the safe and easy in vitro evaluation of trans-translation from ... More
In bacteria, trans-translation is the major quality control system for rescuing stalled ribosomes. It is mediated by tmRNA, a hybrid RNA with properties of both a tRNA and a mRNA, and the small protein SmpB. Because trans-translation is absent in eukaryotes but necessary for bacterial fitness or survival, it is a promising target for the development of novel antibiotics. To facilitate screening of chemical libraries, various reliable in vitro and in vivo systems have been created for assessing trans-translational activity. However, the aim of the current work was to permit the safe and easy in vitro evaluation of trans-translation from pathogenic bacteria, which are obviously the ones we should be targeting. Based on green fluorescent protein (GFP) reassembly during active trans-translation, we have created a cell-free assay adapted to the rapid evaluation of trans-translation in ESKAPE bacteria, with 24 different possible combinations. It can be used for easy high-throughput screening of chemical compounds as well as for exploring the mechanism of trans-translation in these pathogens. Less
To identify approaches to target DNA repair vulnerabilities in cancer we discovered nanomolar potent selective low molecular weight MW allosteric inhibitors of the polymerase function of DNA polymerase Pol including ART ART inhibits the major Pol -mediated DNA repair process Theta-Mediated End Joining without targeting Non-Homologous End Joining In addition ART elicits DNA damage and synthetic lethality in BRCA - or BRCA -mutant tumour cells and enhances the effects of a PARP inhibitor Genetic perturbation screening revealed that defects in the BP Shieldin complex which cause PARP inhibitor resistance result in in vitro and in vivo sensitivity to small molecule ... More
To identify approaches to target DNA repair vulnerabilities in cancer, we discovered nanomolar potent, selective, low molecular weight (MW), allosteric inhibitors of the polymerase function of DNA polymerase Polθ, including ART558. ART558 inhibits the major Polθ-mediated DNA repair process, Theta-Mediated End Joining, without targeting Non-Homologous End Joining. In addition, ART558 elicits DNA damage and synthetic lethality in BRCA1- or BRCA2-mutant tumour cells and enhances the effects of a PARP inhibitor. Genetic perturbation screening revealed that defects in the 53BP1/Shieldin complex, which cause PARP inhibitor resistance, result in in vitro and in vivo sensitivity to small molecule Polθ polymerase inhibitors. Mechanistically, ART558 increases biomarkers of single-stranded DNA and synthetic lethality in 53BP1-defective cells whilst the inhibition of DNA nucleases that promote end-resection reversed these effects, implicating these in the synthetic lethal mechanism-of-action. Taken together, these observations describe a drug class that elicits BRCA-gene synthetic lethality and PARP inhibitor synergy, as well as targeting a biomarker-defined mechanism of PARPi-resistance. Less
Aerogels are ultralight porous materials whose matrix structure can be formed by interlinking nm long M phage particles In theory changing the phage properties would alter the aerogel matrix but attempting this using the current production system leads to heterogeneous lengths A phagemid system that yields a narrow length distribution that can be tuned in nm increments from to nm is designed and independently the persistence length varies from to nm by mutating the coat protein A robotic workflow that automates each step from DNA construction to aerogel synthesis is used to build aerogels This is applied to compare Ni ... More
Aerogels are ultralight porous materials whose matrix structure can be formed by interlinking 880 nm long M13 phage particles. In theory, changing the phage properties would alter the aerogel matrix, but attempting this using the current production system leads to heterogeneous lengths. A phagemid system that yields a narrow length distribution that can be tuned in 0.3 nm increments from 50 to 2500 nm is designed and, independently, the persistence length varies from 14 to 68 nm by mutating the coat protein. A robotic workflow that automates each step from DNA construction to aerogel synthesis is used to build 1200 aerogels. This is applied to compare Ni–MnOx cathodes built using different matrixes, revealing a pareto-optimal relationship between performance metrics. This work demonstrates the application of genetic engineering to create “tuning knobs” to sweep through material parameter space; in this case, toward creating a physically strong and high-capacity battery. Less
Existing protocols for full-length single-cell RNA sequencing produce libraries of high complexity thousands of distinct genes with outstanding sensitivity and specificity of transcript quantification These full-length libraries have the advantage of allowing probing of transcript isoforms are informative regarding single-nucleotide polymorphisms and allow assembly of the VDJ region of the T- and B-cell-receptor sequences Since full-length protocols are mostly plate-based at present they are also suited to profiling cell types where cell numbers are limiting such as rare cell types during development A disadvantage of these methods has been the scalability and cost of the experiments which has limited their ... More
Existing protocols for full-length single-cell RNA sequencing produce libraries of high complexity (thousands of distinct genes) with outstanding sensitivity and specificity of transcript quantification. These full-length libraries have the advantage of allowing probing of transcript isoforms, are informative regarding single-nucleotide polymorphisms and allow assembly of the VDJ region of the T- and B-cell-receptor sequences. Since full-length protocols are mostly plate-based at present, they are also suited to profiling cell types where cell numbers are limiting, such as rare cell types during development. A disadvantage of these methods has been the scalability and cost of the experiments, which has limited their popularity as compared with droplet-based and nanowell approaches. Here, we describe an automated protocol for full-length single-cell RNA sequencing, including both an in-house automated Smart-seq2 protocol and a commercial kit–based workflow. The protocols take 3–5 d to complete, depending on the number of plates processed in a batch. We discuss these two protocols in terms of ease of use, equipment requirements, running time, cost per sample and sequencing quality. By benchmarking the lysis buffers, reverse transcription enzymes and their combinations, we have optimized the in-house automated protocol to dramatically reduce its cost. An automated setup can be adopted easily by a competent researcher with basic laboratory skills and no prior automation experience. These pipelines have been employed successfully for several research projects allied with the Human Cell Atlas initiative (www.humancellatlas.org). Less
Stratified lakes and ponds featuring steep oxygen gradients are significant net sources of greenhouse gases and hotspots in the carbon cycle Despite their significant biogeochemical roles the microbial communities especially in the oxygen depleted compartments are poorly known Here we present a comprehensive dataset including shotgun metagenomes from stratified lakes and ponds mainly located in the boreal and subarctic regions but also including one tropical reservoir and one temperate lake For most lakes and ponds the data includes a vertical sample set spanning from the oxic surface to the anoxic bottom layer The majority of the samples were collected during ... More
Stratified lakes and ponds featuring steep oxygen gradients are significant net sources of greenhouse gases and hotspots in the carbon cycle. Despite their significant biogeochemical roles, the microbial communities, especially in the oxygen depleted compartments, are poorly known. Here, we present a comprehensive dataset including 267 shotgun metagenomes from 41 stratified lakes and ponds mainly located in the boreal and subarctic regions, but also including one tropical reservoir and one temperate lake. For most lakes and ponds, the data includes a vertical sample set spanning from the oxic surface to the anoxic bottom layer. The majority of the samples were collected during the open water period, but also a total of 29 samples were collected from under the ice. In addition to the metagenomic sequences, the dataset includes environmental variables for the samples, such as oxygen, nutrient and organic carbon concentrations. The dataset is ideal for further exploring the microbial taxonomic and functional diversity in freshwater environments and potential climate change impacts on the functioning of these ecosystems. Less
We report the development automation and validation of a D microfluidic liver-on-a-chip for high throughput hepatotoxicity screening the OrganoPlate LiverTox The model is comprised of aggregates of induced pluripotent stem cell iPSC -derived hepatocytes iHep seeded in an extracellular matrix in the organ channel and co-cultured with endothelial cells and THP- monoblasts differentiated to macrophages seeded in the vascular channel of the well Mimetas OrganoPlate -lane A key component of high throughput screening is automation and we report a protocol to seed dose collect and replenish media and add assay reagents in the OrganoPlate -lane using a standard laboratory liquid ... More
We report the development, automation and validation of a 3D, microfluidic liver-on-a-chip for high throughput hepatotoxicity screening, the OrganoPlate LiverTox™. The model is comprised of aggregates of induced pluripotent stem cell (iPSC)-derived hepatocytes (iHep) seeded in an extracellular matrix in the organ channel and co-cultured with endothelial cells and THP-1 monoblasts differentiated to macrophages seeded in the vascular channel of the 96 well Mimetas OrganoPlate 2-lane. A key component of high throughput screening is automation and we report a protocol to seed, dose, collect and replenish media and add assay reagents in the OrganoPlate 2-lane using a standard laboratory liquid handling robot. A combination of secretome measurements and image-based analysis was used to demonstrate stable 15 day cell viability, albumin and urea secretion. Over the same time-period, CYP3A4 activity increased and alpha-fetoprotein secretion decreased suggesting further maturation of the iHeps. Troglitazone, a clinical hepatotoxin, was chosen as a control compound for validation studies. Albumin, urea, hepatocyte nuclear size and viability staining provided Robust Z’factors > 0.2 in plates treated 72 h with 180 μM troglitazone compared with a vehicle control. The viability assay provided the most robust statistic for a Robust Z’ factor = 0.6. A small library of 159 compounds with known liver effects was added to the OrganoPlate LiverTox model for 72 h at 50 μM and the Toxicological Prioritization scores were calculated. A follow up dose-response evaluation of select hits revealed the albumin assay to be the most sensitive in calculating TC50 values. This platform provides a robust, novel model which can be used for high throughput hepatotoxicity screening. Less
Bright yellow BY- tobacco cells combined with the XVE chemically inducible system are one of the most promising plant-based platforms for recombinant protein production This offers a range of benefits including the separation of the cell growth and heterologous gene expression lack of risk of infecting the end product with prions and human viruses or appropriate protein glycosylation and folding However low protein productivity remains a major obstacle that limits the extensive commercialization of bioproduction in plants A number of molecular cell culture and down processing approaches have been made to overcome this problem Media development for the specific nutritional ... More
Bright yellow (BY-2) tobacco cells combined with the XVE chemically inducible system are one of the most promising plant-based platforms for recombinant protein production. This offers a range of benefits, including the separation of the cell growth and heterologous gene expression, lack of risk of infecting the end product with prions and human viruses or appropriate protein glycosylation and folding. However, low protein productivity remains a major obstacle that limits the extensive commercialization of bioproduction in plants. A number of molecular, cell culture and down processing approaches have been made to overcome this problem. Media development for the specific nutritional and hormonal requirements of transgenic plant cells is one of the most efficient cell-culture approaches. We optimized the induction medium towards recombinant protein production in BY-2 and demonstrated the usefulness of evolutionary medium optimization for high-yield protein production in liquid plant cultures. A reliable XVE/GFP model, parallel conducting experiments in a microscale on 96-well plates, and dedicated Gene Game evolutionary optimization software allowed for an effective search of 7611 possible solutions of 11-component media. Within the 4608 formulations tested, the Induct X medium was found with a significant 107.14% increase in protein expression in relation to the standard BY-2 medium. Less
Tankyrases catalyse poly-ADP-ribosylation of their binding partners and the modification serves as a signal for the subsequent proteasomal degradation of these proteins Tankyrases thereby regulate the turnover of many proteins involved in multiple and diverse cellular processes such as mitotic spindle formation telomere homeostasis and Wnt -catenin signalling In recent years tankyrases have become attractive targets for the development of inhibitors as potential therapeutics against cancer and fibrosis Further it has become clear that tankyrases are not only enzymes but also act as scaffolding proteins forming large cellular signalling complexes While many potent and selective tankyrase inhibitors of the poly-ADP-ribosylation ... More
Tankyrases catalyse poly-ADP-ribosylation of their binding partners and the modification serves as a signal for the subsequent proteasomal degradation of these proteins. Tankyrases thereby regulate the turnover of many proteins involved in multiple and diverse cellular processes, such as mitotic spindle formation, telomere homeostasis and Wnt/β-catenin signalling. In recent years, tankyrases have become attractive targets for the development of inhibitors as potential therapeutics against cancer and fibrosis. Further, it has become clear that tankyrases are not only enzymes, but also act as scaffolding proteins forming large cellular signalling complexes. While many potent and selective tankyrase inhibitors of the poly-ADP-ribosylation function exist, the inhibition of tankyrase scaffolding functions remains scarcely explored. In this work we present a robust, simple and cost-effective high-throughput screening platform based on FRET for the discovery of small molecule probes targeting the protein–protein interactions of tankyrases. Validatory screening with the platform led to the identification of two compounds with modest binding affinity to the tankyrase 2 ARC4 domain, demonstrating the applicability of this approach. The platform will facilitate identification of small molecules binding to tankyrase ARC or SAM domains and help to advance a structure-guided development of improved chemical probes targeting tankyrase oligomerization and substrate protein interactions. Less
The pharmaceutical industry is continuing to face high research and development R D costs and low overall success rates of clinical compounds during drug development There is an increasing demand for development and validation of healthy or disease-relevant and physiological human cellular models that can be implemented in early-stage discovery thereby shifting attrition of future therapeutics to a point in discovery at which the costs are significantly lower There needs to be a paradigm shift in the early drug discovery phase which is lengthy and costly away from simplistic cellular models that show an inability to effectively and efficiently reproduce ... More
The pharmaceutical industry is continuing to face high research and development (R&D) costs and low overall success rates of clinical compounds during drug development. There is an increasing demand for development and validation of healthy or disease-relevant and physiological human cellular models that can be implemented in early-stage discovery, thereby shifting attrition of future therapeutics to a point in discovery at which the costs are significantly lower. There needs to be a paradigm shift in the early drug discovery phase (which is lengthy and costly), away from simplistic cellular models that show an inability to effectively and efficiently reproduce healthy or human disease-relevant states to steer target and compound selection for safety, pharmacology, and efficacy questions. This perspective article covers the various stages of early drug discovery from target identification (ID) and validation to the hit/lead discovery phase, lead optimization, and preclinical safety. We outline key aspects that should be considered when developing, qualifying, and implementing complex in vitro models (CIVMs) during these phases, because criteria such as cell types (e.g., cell lines, primary cells, stem cells, and tissue), platform (e.g., spheroids, scaffolds or hydrogels, organoids, microphysiological systems, and bioprinting), throughput, automation, and single and multiplexing endpoints will vary. The article emphasizes the need to adequately qualify these CIVMs such that they are suitable for various applications (e.g., context of use) of drug discovery and translational research. The article ends looking to the future, in which there is an increase in combining computational modeling, artificial intelligence and machine learning (AI/ML), and CIVMs. Less
Interleukin- IL- is a key cytokine implicated in the pathogenesis of autoimmune disorders including psoriasis and ulcerative colitis Although targeted IL- antibody therapeutics are used clinically there are no small-molecule therapeutics that selectively inhibit IL- signaling To address this gap we developed a high-throughput screening strategy employing an IL- -responsive cell-based luciferase reporter gene assay as the primary screen with cellular cytotoxicity and off-target counter screening assays to identify IL- pathway-specific inhibitors The primary screening assay utilized avian DT cells genetically engineered to overexpress IL- R IL- R STAT and firefly luciferase in a -well format Treatment of these cells ... More
Interleukin-23 (IL-23) is a key cytokine implicated in the pathogenesis of autoimmune disorders, including psoriasis and ulcerative colitis. Although targeted IL-23 antibody therapeutics are used clinically, there are no small-molecule therapeutics that selectively inhibit IL-23 signaling. To address this gap, we developed a high-throughput screening strategy employing an IL-23-responsive cell-based luciferase reporter gene assay as the primary screen, with cellular cytotoxicity and off-target counter screening assays to identify IL-23 pathway-specific inhibitors. The primary screening assay utilized avian DT40 cells, genetically engineered to overexpress IL-23R, IL-12Rβ1, STAT5, and firefly luciferase, in a 1536-well format. Treatment of these cells with IL-23 resulted in the phosphorylation and activation of STAT5, which was completely inhibited by the pan-JAK inhibitor tofacitinib. Assay performance was robust, with signal-to-background >7-fold and Z′ > 0.5 over 40 screening plates (approximately 24,000 compounds), with a hit rate of 5% (>66.9% activity cutoff). Of these 1288 hits, 66% were identified as cytotoxic by incubating the IL-23 reporter cells with compound overnight and measuring cell viability. Further assessment of specificity via examination of impact on off-target IFN-γ signaling eliminated an additional 230 compounds, leaving 209 that were evaluated for dose–response activity. Of these compounds, 24 exhibited IC50 values of <7 µM and ≥80% inhibition of IL-23 activity, with >3-fold selectivity over IFN-γ inhibition, thus representing promising starting points for prospective IL-23 pathway small-molecule inhibitors. Less
We present a deep learning-based framework to design and quantify point-of-care sensors As a use-case we demonstrated a low-cost and rapid paper-based vertical flow assay VFA for high sensitivity C-Reactive Protein hsCRP testing commonly used for assessing risk of cardio-vascular disease CVD A machine learning-based framework was developed to determine an optimal configuration of immunoreaction spots and conditions spatially-multiplexed on a sensing membrane and to accurately infer target analyte concentration Using a custom-designed handheld VFA reader a clinical study with human samples showed a competitive coefficient-of-variation of and linearity of R among blindly-tested VFAs in the hsCRP range i e ... More
We present a deep learning-based framework to design and quantify point-of-care sensors. As a use-case, we demonstrated a low-cost and rapid paper-based vertical flow assay (VFA) for high sensitivity C-Reactive Protein (hsCRP) testing, commonly used for assessing risk of cardio-vascular disease (CVD). A machine learning-based framework was developed to (1) determine an optimal configuration of immunoreaction spots and conditions, spatially-multiplexed on a sensing membrane, and (2) to accurately infer target analyte concentration. Using a custom-designed handheld VFA reader, a clinical study with 85 human samples showed a competitive coefficient-of-variation of 11.2% and linearity of R2 = 0.95 among blindly-tested VFAs in the hsCRP range (i.e., 0–10 mg/L). We also demonstrated a mitigation of the hook-effect due to the multiplexed immunoreactions on the sensing membrane. This paper-based computational VFA could expand access to CVD testing, and the presented framework can be broadly used to design cost-effective and mobile point-of-care sensors. Less
Small-molecule drug discovery can be hindered by the formation of aggregates that act as non-selective inhibitors of drug targets Such aggregates appear as false positives in high-throughput screening campaigns and can bedevil structure-activity relationships during compound optimization Protocols are described for resonant waveguide grating RWG and dynamic light scattering DLS as microplate-based high-throughput approaches to identify compound aggregation Resonant waveguide grating and dynamic light scattering give equivalent results for the compound test set as assessed with Bland-Altman analysis
The over-expression and aggregation of -synuclein Syn are linked to the onset and pathology of Parkinson s disease Native monomeric Syn exists in an intrinsically disordered ensemble of interconverting conformations which has made its therapeutic targeting by small molecules highly challenging Nonetheless here we successfully target the monomeric structural ensemble of Syn and thereby identify novel drug-like small molecules that impact multiple pathogenic processes Using a surface plasmon resonance high-throughput screen in which monomeric Syn is incubated with microchips arrayed with tethered compounds we identified novel Syn interacting drug-like compounds Because these small molecules could impact a variety of Syn ... More
The over-expression and aggregation of α-synuclein (αSyn) are linked to the onset and pathology of Parkinson’s disease. Native monomeric αSyn exists in an intrinsically disordered ensemble of interconverting conformations, which has made its therapeutic targeting by small molecules highly challenging. Nonetheless, here we successfully target the monomeric structural ensemble of αSyn and thereby identify novel drug-like small molecules that impact multiple pathogenic processes. Using a surface plasmon resonance high-throughput screen, in which monomeric αSyn is incubated with microchips arrayed with tethered compounds, we identified novel αSyn interacting drug-like compounds. Because these small molecules could impact a variety of αSyn forms present in the ensemble, we tested representative hits for impact on multiple αSyn malfunctions in vitro and in cells including aggregation and perturbation of vesicular dynamics. We thereby identified a compound that inhibits αSyn misfolding and is neuroprotective, multiple compounds that restore phagocytosis impaired by αSyn overexpression, and a compound blocking cellular transmission of αSyn. Our studies demonstrate that drug-like small molecules that interact with native αSyn can impact a variety of its pathological processes. Thus, targeting the intrinsically disordered ensemble of αSyn offers a unique approach to the development of small molecule research tools and therapeutics for Parkinson’s disease. Less
Discovery of novel Mnk inhibitors using mutation-based induced-fit virtual high-throughput screening
Mnk kinases Mnk and are downstream effectors of Map kinase pathways and regulate phosphorylation of eukaryotic initiation factor E Engagement of the Mnk pathway is critical in acute myeloid leukemia AML leukemogenesis and Mnk inhibitors have potent antileukemic properties in vitro and in vivo suggesting that targeting Mnk kinases may provide a novel approach for treating AML Here we report the development and application of a mutation-based induced-fit in silico screen to identify novel Mnk inhibitors The Mnk structure was modeled by temporarily mutating an amino acid that obstructs the ATP-binding site in the Mnk crystal structure while carrying out ... More
Mnk kinases (Mnk1 and 2) are downstream effectors of Map kinase pathways and regulate phosphorylation of eukaryotic initiation factor 4E. Engagement of the Mnk pathway is critical in acute myeloid leukemia (AML) leukemogenesis and Mnk inhibitors have potent antileukemic properties in vitro and in vivo, suggesting that targeting Mnk kinases may provide a novel approach for treating AML. Here, we report the development and application of a mutation-based induced-fit in silico screen to identify novel Mnk inhibitors. The Mnk1 structure was modeled by temporarily mutating an amino acid that obstructs the ATP-binding site in the Mnk1 crystal structure while carrying out docking simulations of known inhibitors. The hit compounds display activity in Mnk biochemical and cellular assays, including acute myeloid leukemia progenitors. This approach will enable further rational structure-based drug design of new Mnk inhibitors and potentially novel ways of therapeutically targeting this kinase. Less
Human NimA-related kinases Neks have multiple mitotic and non-mitotic functions but few substrates are known We systematically determined the phosphorylation-site motifs for the entire Nek kinase family except for Nek While all Nek kinases strongly select for hydrophobic residues in the position the family separates into four distinct groups based on specificity for a serine versus threonine phospho-acceptor and preference for basic or acidic residues in other positions Unlike Nek -Nek Nek is a dual-specificity kinase that efficiently phosphorylates itself and peptide substrates on serine and tyrosine and its activity is enhanced by tyrosine auto-phosphorylation Nek dual-specificity depends on residues ... More
Human NimA-related kinases (Neks) have multiple mitotic and non-mitotic functions, but few substrates are known. We systematically determined the phosphorylation-site motifs for the entire Nek kinase family, except for Nek11. While all Nek kinases strongly select for hydrophobic residues in the −3 position, the family separates into four distinct groups based on specificity for a serine versus threonine phospho-acceptor, and preference for basic or acidic residues in other positions. Unlike Nek1-Nek9, Nek10 is a dual-specificity kinase that efficiently phosphorylates itself and peptide substrates on serine and tyrosine, and its activity is enhanced by tyrosine auto-phosphorylation. Nek10 dual-specificity depends on residues in the HRD+2 and APE-4 positions that are uncommon in either serine/threonine or tyrosine kinases. Finally, we show that the phosphorylation-site motifs for the mitotic kinases Nek6, Nek7 and Nek9 are essentially identical to that of their upstream activator Plk1, suggesting that Nek6/7/9 function as phospho-motif amplifiers of Plk1 signaling. Less
Specificity within protein kinase signaling cascades is determined by direct and indirect interactions between kinases and their substrates While the impact of localization and recruitment on kinase substrate targeting can be readily assessed evaluating the relative importance of direct phosphorylation site interactions remains challenging In this study we examine the STE family of protein serine threonine kinases to investigate basic mechanisms of substrate targeting We used peptide arrays to define the phosphorylation site specificity for the majority of STE kinases and categorized them into four distinct groups Using structure-guided mutagenesis we identified key specificity-determining residues within the kinase catalytic cleft ... More
Specificity within protein kinase signaling cascades is determined by direct and indirect interactions between kinases and their substrates. While the impact of localization and recruitment on kinase–substrate targeting can be readily assessed, evaluating the relative importance of direct phosphorylation site interactions remains challenging. In this study, we examine the STE20 family of protein serine–threonine kinases to investigate basic mechanisms of substrate targeting. We used peptide arrays to define the phosphorylation site specificity for the majority of STE20 kinases and categorized them into four distinct groups. Using structure-guided mutagenesis, we identified key specificity-determining residues within the kinase catalytic cleft, including an unappreciated role for the kinase β3–αC loop region in controlling specificity. Exchanging key residues between the STE20 kinases p21-activated kinase 4 (PAK4) and Mammalian sterile 20 kinase 4 (MST4) largely interconverted their phosphorylation site preferences. In cells, a reprogrammed PAK4 mutant, engineered to recognize MST substrates, failed to phosphorylate PAK4 substrates or to mediate remodeling of the actin cytoskeleton. In contrast, this mutant could rescue signaling through the Hippo pathway in cells lacking multiple MST kinases. These observations formally demonstrate the importance of catalytic site specificity for directing protein kinase signal transduction pathways. Our findings further suggest that phosphorylation site specificity is both necessary and sufficient to mediate distinct signaling outputs of STE20 kinases and imply broad applicability to other kinase signaling systems. Less
Here we present a compendium of single-cell transcriptomic data from the model organism Mus musculus that comprises more than cells from organs and tissues These data represent a new resource for cell biology reveal gene expression in poorly characterized cell populations and enable the direct and controlled comparison of gene expression in cell types that are shared between tissues such as T lymphocytes and endothelial cells from different anatomical locations Two distinct technical approaches were used for most organs one approach microfluidic droplet-based -end counting enabled the survey of thousands of cells at relatively low coverage whereas the other full-length ... More
Here we present a compendium of single-cell transcriptomic data from the model organism Mus musculus that comprises more than 100,000 cells from 20 organs and tissues. These data represent a new resource for cell biology, reveal gene expression in poorly characterized cell populations and enable the direct and controlled comparison of gene expression in cell types that are shared between tissues, such as T lymphocytes and endothelial cells from different anatomical locations. Two distinct technical approaches were used for most organs: one approach, microfluidic droplet-based 3′-end counting, enabled the survey of thousands of cells at relatively low coverage, whereas the other, full-length transcript analysis based on fluorescence-activated cell sorting, enabled the characterization of cell types with high sensitivity and coverage. The cumulative data provide the foundation for an atlas of transcriptomic cell biology. Less
Structure-based drug design SBDD heavily relies on the production of high-resolution three-dimensional D structures of the drug target in the presence or absence of the drug candidate X-ray crystallography is the predominant technique accounting for higher than of the structures in Protein Data Bank PDB considering the complexes involving protein and inhibitors Macromolecular X-ray crystallography provides an important and powerful technique in studying the specific interactions of a particular drug with its protein target at the atomic level that can help improve the drug design process It is the main technique used to obtain D information for binary complexes involving ... More
Structure-based drug design (SBDD) heavily relies on the production of high-resolution (<2Å) three-dimensional (3D) structures of the drug target in the presence or absence of the drug candidate [1]. X-ray crystallography is the predominant technique accounting for higher than 94% of the structures in Protein Data Bank (PDB), considering the complexes involving protein and inhibitors [2–4]. Macromolecular X-ray crystallography provides an important and powerful technique in studying the specific interactions of a particular drug with its protein target at the atomic level that can help improve the drug design process [5]. It is the main technique used to obtain 3D information for binary complexes involving protein and drugs [6]. One of the major ‘bottlenecks’ in X-ray crystallography is the lack of generalized methods for high quality crystal production. Since protein crystallization mechanism details remain unknown, protein crystallization is a complicated and time-consuming process and requires performing a significant number of trial-and-error experiments involving systematic testing of variable chemical and physical parameters [7]. High-throughput (HT) structural biology coincided with the dawn of the genomic era in biology requires the automation, miniaturization, and parallelization of protein crystallization in order to reach the capacity necessary for large-scale structure determination efforts [8]. HT protein crystallization screening (HTPCS) technologies appeared on the protein crystallization scene more than three decades ago and have since allowed accessing hundreds to thousands of protein crystallization conditions, thereby greatly impacting HT structural biology [9]. HTPCS has helped to identify critical components required for HT crystallization efforts [7]. In recent years, the rapid developments of manipulation techniques and devices provide effective and reliable solutions for protein crystallization screening with HT and low consumption. In spite of their advances, HTPCS has suffered from two main handicaps, namely, poor hit rate in protein crystallization screening and lack of predictive power of the scoring functions. To overcome these handicaps, several projects have recently been initiated to construct ‘smart systems’ that are not only capable of rapidly performing a large number of crystallization trials, but also scripting and triggering certain events based on the collected data used in predict the outcome of a protein x-ray crystallization trial [10]. In this contest, we will outline recent efforts in HTPCS that could improve the success rate of the structural pipeline. We will discuss the challenge and some of the possible avenues in that direction. Less
High-throughput single-cell RNA-seq methods assign limited unique molecular identifier UMI counts as gene expression values to single cells from shallow sequence reads and detect limited gene counts We thus developed a high-throughput single-cell RNA-seq method Quartz-Seq to overcome these issues Our improvements in the reaction steps make it possible to effectively convert initial reads to UMI counts at a rate of and detect more genes To demonstrate the power of Quartz-Seq we analyzed approximately transcriptomes from in vitro embryonic stem cells and an in vivo stromal vascular fraction with a limited number of reads
In recent years highly detailed characterization of adult bone marrow BM myeloid progenitors has been achieved and as a result the impact of somatic defects on different hematopoietic lineage fate decisions can be precisely determined Fetal liver FL hematopoietic progenitor cells HPCs are poorly characterized in comparison potentially hindering the study of the impact of genetic alterations on midgestation hematopoiesis Numerous disorders for example infant acute leukemias have in utero origins and their study would therefore benefit from the ability to isolate highly purified progenitor subsets We previously demonstrated that a Runx distal promoter P -GFP proximal promoter P -hCD ... More
In recent years, highly detailed characterization of adult bone marrow (BM) myeloid progenitors has been achieved and, as a result, the impact of somatic defects on different hematopoietic lineage fate decisions can be precisely determined. Fetal liver (FL) hematopoietic progenitor cells (HPCs) are poorly characterized in comparison, potentially hindering the study of the impact of genetic alterations on midgestation hematopoiesis. Numerous disorders, for example infant acute leukemias, have in utero origins and their study would therefore benefit from the ability to isolate highly purified progenitor subsets. We previously demonstrated that a Runx1 distal promoter (P1)-GFP::proximal promoter (P2)-hCD4 dual-reporter mouse (Mus musculus) model can be used to identify adult BM progenitor subsets with distinct lineage preferences. In this study, we undertook the characterization of the expression of Runx1-P1-GFP and P2-hCD4 in FL. Expression of P2-hCD4 in the FL immunophenotypic Megakaryocyte-Erythroid Progenitor (MEP) and Common Myeloid Progenitor (CMP) compartments corresponded to increased granulocytic/monocytic/megakaryocytic and decreased erythroid specification. Moreover, Runx1-P2-hCD4 expression correlated with several endogenous cell surface markers’ expression, including CD31 and CD45, providing a new strategy for prospective identification of highly purified fetal myeloid progenitors in transgenic mouse models. We utilized this methodology to compare the impact of the deletion of either total RUNX1 or RUNX1C alone and to determine the fetal HPCs lineages most substantially affected. This new prospective identification of FL progenitors therefore raises the prospect of identifying the underlying gene networks responsible with greater precision than previously possible. Less
There is a pressing need to improve approaches for drug discovery related to neuropsychiatric disorders NSDs Therapeutic discovery in neuropsychiatric disorders would benefit from screening assays that can measure changes in complex phenotypes linked to disease mechanisms However traditional assays that track complex neuronal phenotypes such as neuronal connectivity exhibit poor scalability and are not compatible with high-throughput screening HTS procedures Therefore we created a neuronal phenotypic assay platform that focused on improving the scalability and affordability of neuron-based assays capable of tracking disease-relevant phenotypes First using inexpensive laboratory-level automation we industrialized primary neuronal culture production which enabled the creation ... More
There is a pressing need to improve approaches for drug discovery related to neuropsychiatric disorders (NSDs). Therapeutic discovery in neuropsychiatric disorders would benefit from screening assays that can measure changes in complex phenotypes linked to disease mechanisms. However, traditional assays that track complex neuronal phenotypes, such as neuronal connectivity, exhibit poor scalability and are not compatible with high-throughput screening (HTS) procedures. Therefore, we created a neuronal phenotypic assay platform that focused on improving the scalability and affordability of neuron-based assays capable of tracking disease-relevant phenotypes. First, using inexpensive laboratory-level automation, we industrialized primary neuronal culture production, which enabled the creation of scalable assays within functioning neural networks. We then developed a panel of phenotypic assays based on culturing of primary neurons from genetically modified mice expressing HTS-compatible reporters that capture disease-relevant phenotypes. We demonstrated that a library of 1,280 compounds was quickly screened against both assays using only a few litters of mice in a typical academic laboratory setting. Finally, we implemented one assay in a fully automated high-throughput academic screening facility, illustrating the scalability of assays designed using this platform. These methodological improvements simplify the creation of highly scalable neuron-based phenotypic assays designed to improve drug discovery in CNS disorders. Less
This review provides an overview of the science of high-throughput screening HTS within the pharmaceutical industry and the greater drug discovery community From its origins in the early s to the current state of the art key aspects of the process are introduced and described in increasing levels of detail Examples of technologies employed in the automation of HTS are provided together with an evaluation of their applicability and limitations The various detection modalities typically encountered and their suitability to high-density screening formats or well are described The increasing importance of informatics in screen design data interpretation quality control and ... More
This review provides an overview of the science of high-throughput screening (HTS) within the pharmaceutical industry and the greater drug discovery community. From its origins in the early 1990s to the current state of the art, key aspects of the process are introduced and described in increasing levels of detail. Examples of technologies employed in the automation of HTS are provided, together with an evaluation of their applicability and limitations. The various detection modalities typically encountered, and their suitability to high-density screening formats (96, 386, 1536, or 3456 well) are described. The increasing importance of informatics in screen design, data interpretation, quality control, and its contribution to the development of future HTS strategies is introduced. Current and future trends of how HTS is employed to meet the changing needs for new drug discovery are explored, including the parallel use of complementary screening modalities to sample diverse chemical matter and identify the best starting points for drug discovery programs. Less
The androgen receptor AR NR C is a nuclear receptor whose main function is acting as a transcription factor regulating gene expression for male sexual development and maintaining accessory sexual organ function It is also a necessary component of female fertility by affecting the functionality of ovarian follicles and ovulation Pathological processes involving AR include Kennedy s disease and Klinefelter s syndrome as well as prostate ovarian and testicular cancer Strict regulation of sex hormone signaling is required for normal reproductive organ development and function Therefore testing small molecules for their ability to modulate AR is a first step in ... More
The androgen receptor (AR, NR3C4) is a nuclear receptor whose main function is acting as a transcription factor regulating gene expression for male sexual development and maintaining accessory sexual organ function. It is also a necessary component of female fertility by affecting the functionality of ovarian follicles and ovulation. Pathological processes involving AR include Kennedy’s disease and Klinefelter’s syndrome, as well as prostate, ovarian, and testicular cancer. Strict regulation of sex hormone signaling is required for normal reproductive organ development and function. Therefore, testing small molecules for their ability to modulate AR is a first step in identifying potential endocrine disruptors. We screened the Tox21 10K compound library in a quantitative high-throughput format to identify activators of AR using two reporter gene cell lines, AR β-lactamase (AR-bla) and AR-luciferase (AR-luc). Seventy-five compounds identified through the primary assay were characterized as potential agonists or inactives through confirmation screens and secondary assays. Biochemical binding and AR nuclear translocation assays were performed to confirm direct binding and activation of AR from these compounds. The top seventeen compounds identified were found to bind to AR, and sixteen of them translocated AR from the cytoplasm into the nucleus. Five potentially novel or not well-characterized AR agonists were discovered through primary and follow-up studies. We have identified multiple AR activators, including known AR agonists such as testosterone, as well as novel/not well-known compounds such as prulifloxacin. The information gained from the current study can be directly used to prioritize compounds for further in-depth toxicological evaluations, as well as their potential to disrupt the endocrine system via AR activation. Less
Antibiotic-resistant bacterial infections are increasingly prevalent worldwide and there is an urgent need for novel classes of antibiotics capable of overcoming existing resistance mechanisms One potential antibiotic target is the bacterial single-stranded DNA binding protein SSB which serves as a hub for DNA repair recombination and replication Eight highly conserved residues at the C-terminus of SSB use direct protein protein interactions PPIs to recruit more than a dozen important genome maintenance proteins to single-stranded DNA Mutations that disrupt PPIs with the C-terminal tail of SSB are lethal suggesting that small-molecule inhibitors of these critical SSB PPIs could be effective antibacterial ... More
Antibiotic-resistant bacterial infections are increasingly prevalent worldwide, and there is an urgent need for novel classes of antibiotics capable of overcoming existing resistance mechanisms. One potential antibiotic target is the bacterial single-stranded DNA binding protein (SSB), which serves as a hub for DNA repair, recombination, and replication. Eight highly conserved residues at the C-terminus of SSB use direct protein–protein interactions (PPIs) to recruit more than a dozen important genome maintenance proteins to single-stranded DNA. Mutations that disrupt PPIs with the C-terminal tail of SSB are lethal, suggesting that small-molecule inhibitors of these critical SSB PPIs could be effective antibacterial agents. As a first step toward implementing this strategy, we have developed orthogonal high-throughput screening assays to identify small-molecule inhibitors of the Klebsiella pneumonia SSB-PriA interaction. Hits were identified from an initial screen of 72,474 compounds using an AlphaScreen (AS) primary screen, and their activity was subsequently confirmed in an orthogonal fluorescence polarization (FP) assay. As an additional control, an FP assay targeted against an unrelated eukaryotic PPI was used to confirm specificity for the SSB-PriA interaction. Nine potent and selective inhibitors produced concentration–response curves with IC50 values of <40 μM, and two compounds were observed to directly bind to PriA, demonstrating the success of this screen strategy. Less
Evaluating the ligandability of a protein target is a key component when defining hit-finding strategies or when prioritize among drug targets Computational as well as biophysical approaches based on nuclear magnetic resonance NMR fragment screening are powerful approaches but suffer from specific constraints that limit their usage Here we demonstrate the applicability of high-throughput thermal scanning HTTS as a simple and generic biophysical fragment screening method to reproduce assessments from NMR-based screening By applying this method to a large set of proteins we can furthermore show that the assessment is predictive of the success of high-throughput screening HTS The few ... More
Evaluating the ligandability of a protein target is a key component when defining hit-finding strategies or when prioritize among drug targets. Computational as well as biophysical approaches based on nuclear magnetic resonance (NMR) fragment screening are powerful approaches but suffer from specific constraints that limit their usage. Here, we demonstrate the applicability of high-throughput thermal scanning (HTTS) as a simple and generic biophysical fragment screening method to reproduce assessments from NMR-based screening. By applying this method to a large set of proteins we can furthermore show that the assessment is predictive of the success of high-throughput screening (HTS). The few divergences for targets of low ligandability originate from the sensitivity differences of the orthogonal biophysical methods. We thus applied a new strategy making use of modulations in the solvent structure to improve assay sensitivity. This novel approach enables improved ligandability assessments in accordance with NMR-based assessments and more importantly positions the methodology as a valuable option for biophysical fragment screening. Less
Paper microzone plates in combination with a noncontact liquid handling robot were demonstrated as tools for studying the stability of enzymes stored on paper The effect of trehalose and SU- epoxy novolac resin SU- on the stability of horseradish peroxidase HRP was studied in both a short-term experiment where the activity of various concentrations of HRP dried on paper were measured after h and a long-term experiment where the activity of a single concentration of HRP dried and stored on paper was monitored for days SU- was found to stabilize HRP up to times more than trehalose in the short-term ... More
Paper microzone plates in combination with a noncontact liquid handling robot were demonstrated as tools for studying the stability of enzymes stored on paper. The effect of trehalose and SU-8 epoxy novolac resin (SU-8) on the stability of horseradish peroxidase (HRP) was studied in both a short-term experiment, where the activity of various concentrations of HRP dried on paper were measured after 1 h, and a long-term experiment, where the activity of a single concentration of HRP dried and stored on paper was monitored for 61 days. SU-8 was found to stabilize HRP up to 35 times more than trehalose in the short-term experiment for comparable concentrations of the two reagents, and a 1% SU-8 solution was found to stabilize HRP approximately 2 times more than a 34% trehalose solution in both short- and long-term experiments. The results suggest that SU-8 is a promising candidate for use as an enzyme-stabilizing reagent for paper-based diagnostic devices and that the short-term experiment could be used to quickly evaluate the capacity of various reagents for stabilizing enzymes to identify and characterize new enzyme-stabilizing reagents. Less
MEK is an upstream kinase in MAPK signaling pathways where it phosphorylates p MAPK and JNK in response to mitogenic and cellular stress queues MEK is overexpressed and induces metastasis in advanced prostate cancer lesions However the value of MEK as an oncology target has not been pharmacologically validated because selective chemical probes targeting MEK have not been developed Despite a high level of sequence homology in the ATP-binding site most reported MEK inhibitors are selective for MEK and display reduced potency toward other MEKs Here we present the first functional and binding selectivity-profiling platform of the MEK family We ... More
MEK4 is an upstream kinase in MAPK signaling pathways where it phosphorylates p38 MAPK and JNK in response to mitogenic and cellular stress queues. MEK4 is overexpressed and induces metastasis in advanced prostate cancer lesions. However, the value of MEK4 as an oncology target has not been pharmacologically validated because selective chemical probes targeting MEK4 have not been developed. Despite a high level of sequence homology in the ATP-binding site, most reported MEK inhibitors are selective for MEK1/2 and display reduced potency toward other MEKs. Here, we present the first functional and binding selectivity-profiling platform of the MEK family. We applied the platform to profile a set of known kinase inhibitors and used the results to develop an in silico approach for small molecule docking against MEK proteins. The docking studies identified molecular features of the ligands and corresponding amino acids in MEK proteins responsible for high affinity binding versus those driving selectivity. WaterLOGSY and saturation transfer difference (STD) NMR spectroscopy techniques were utilized to understand the binding modes of active compounds. Further minor synthetic manipulations provide a proof of concept by showing how information gained through this platform can be utilized to perturb selectivity across the MEK family. This inhibitor-based approach pinpoints key features governing MEK family selectivity and clarifies empirical selectivity profiles for a set of kinase inhibitors. Going forward, the platform provides a rationale for facilitating the development of MEK-selective inhibitors, particularly MEK4 selective inhibitors, and repurposing of kinase inhibitors for probing the structural selectivity of isoforms. Less
We have developed a microplate reader that records a complete high-quality fluorescence emission spectrum on a well-by-well basis under true high-throughput screening HTS conditions The read time for an entire -well plate is less than min This instrument is particularly well suited for assays based on fluorescence resonance energy transfer FRET Intramolecular protein biosensors with genetically encoded green fluorescent protein GFP donor and red fluorescent protein RFP acceptor tags at positions sensitive to structural changes were stably expressed and studied in living HEK cells Accurate quantitation of FRET was achieved by decomposing each observed spectrum into a linear combination of ... More
We have developed a microplate reader that records a complete high-quality fluorescence emission spectrum on a well-by-well basis under true high-throughput screening (HTS) conditions. The read time for an entire 384-well plate is less than 3 min. This instrument is particularly well suited for assays based on fluorescence resonance energy transfer (FRET). Intramolecular protein biosensors with genetically encoded green fluorescent protein (GFP) donor and red fluorescent protein (RFP) acceptor tags at positions sensitive to structural changes were stably expressed and studied in living HEK cells. Accurate quantitation of FRET was achieved by decomposing each observed spectrum into a linear combination of four component (basis) spectra (GFP emission, RFP emission, water Raman, and cell autofluorescence). Excitation and detection are both conducted from the top, allowing for thermoelectric control of the sample temperature from below. This spectral unmixing plate reader (SUPR) delivers an unprecedented combination of speed, precision, and accuracy for studying ensemble-averaged FRET in living cells. It complements our previously reported fluorescence lifetime plate reader, which offers the feature of resolving multiple FRET populations within the ensemble. The combination of these two direct waveform-recording technologies greatly enhances the precision and information content for HTS in drug discovery. Less
Cancer cell metabolism is a complex dynamic network of regulated pathways Interrogation of this network would benefit from rapid sensitive techniques that are adaptable to high-throughput formats facilitating novel compound screening This requires assays that have minimal sample preparation and are adaptable to lower-volume -well formats and automation Here we describe bioluminescent glucose lactate glutamine and glutamate detection assays that are well suited for high-throughput analysis of two major metabolic pathways in cancer cells glycolysis and glutaminolysis The sensitivity pmol sample broad linear range M and wide dynamic range -fold are advantageous for measuring both extracellular and intracellular metabolites Importantly ... More
Cancer cell metabolism is a complex, dynamic network of regulated pathways. Interrogation of this network would benefit from rapid, sensitive techniques that are adaptable to high-throughput formats, facilitating novel compound screening. This requires assays that have minimal sample preparation and are adaptable to lower-volume 384-well formats and automation. Here we describe bioluminescent glucose, lactate, glutamine, and glutamate detection assays that are well suited for high-throughput analysis of two major metabolic pathways in cancer cells: glycolysis and glutaminolysis. The sensitivity (1–5 pmol/sample), broad linear range (0.1–100 µM), and wide dynamic range (>100-fold) are advantageous for measuring both extracellular and intracellular metabolites. Importantly, the assays incorporate rapid inactivation of endogenous enzymes, eliminating deproteinization steps required by other methods. Using ovarian cancer cell lines as a model system, the assays were used to monitor changes in glucose and glutamine consumption and lactate and glutamate secretion over time. Homogeneous formats of the lactate and glutamate assays were robust (Z′ = 0.6–0.9) and could be multiplexed with a real-time viability assay to generate internally controlled data. Screening a small-compound library with these assays resulted in the identification of both inhibitors and activators of lactate and glutamate production. Less
The farnesoid X receptor FXR is a nuclear receptor responsible for homeostasis of bile acids lipids and glucose Compounds that alter endogenous FXR signaling can be used as therapeutic candidates or identified as potentially hazardous compounds depending on exposure doses and health states Therefore there is an increasing need for high-throughput screening assays of FXR activity to profile large numbers of environmental chemicals and drugs This chapter describes a workflow of FXR modulator identification and characterization To identify compounds that modulate FXR transactivation at the cellular level we first screen compounds from the Tox K compound library in an FXR-driven ... More
The farnesoid X receptor (FXR) is a nuclear receptor responsible for homeostasis of bile acids, lipids, and glucose. Compounds that alter endogenous FXR signaling can be used as therapeutic candidates or identified as potentially hazardous compounds depending on exposure doses and health states. Therefore, there is an increasing need for high-throughput screening assays of FXR activity to profile large numbers of environmental chemicals and drugs. This chapter describes a workflow of FXR modulator identification and characterization. To identify compounds that modulate FXR transactivation at the cellular level, we first screen compounds from the Tox21 10 K compound library in an FXR-driven beta-lactamase reporter gene assay multiplexed with a cell viability assay in the same well of the 1536-well plates. The selected compounds are then tested biochemically for their ability to modulate FXR-coactivator binding interactions using a time-resolved fluorescence resonance energy transfer (TR-FRET) coactivator assay. The assay results from the workflow can be used to prioritize compounds for more extensive investigations. Less
Oral agents targeting Janus-associated kinases JAKs are promising new agents in clinical development To better understand the relationship between JAK inhibition and biological outcome compounds targeting JAKs were evaluated in peripheral human whole blood To date these analyses are low throughput and costly Here we developed a robust -well high-throughput flow-based assay approach to screen small molecules for JAK STAT signaling inhibition in human whole blood This assay platform provides a highly sensitive analysis of signaling events in blood and facilitates measurement of target engagement Further the automation technologies and process optimizations developed here overcame sample integrity handling and multiparametric ... More
Oral agents targeting Janus-associated kinases (JAKs) are promising new agents in clinical development. To better understand the relationship between JAK inhibition and biological outcome, compounds targeting JAKs were evaluated in peripheral human whole blood. To date, these analyses are low throughput and costly. Here, we developed a robust 384-well, high-throughput flow-based assay approach to screen small molecules for JAK/STAT signaling inhibition in human whole blood. This assay platform provides a highly sensitive analysis of signaling events in blood and facilitates measurement of target engagement. Further, the automation technologies and process optimizations developed here overcame sample integrity, handling, and multiparametric data analysis bottlenecks without affecting assay performance. Together these efforts dramatically increased sample throughput compared to conventional manual flow cytometric approaches and enabled development of novel JAK/STAT inhibitors. Less
Cytokines serve as a major mechanism of communication between immune cells and are the functional molecules at the end of immune pathways Abnormalities in cytokines are involved in a wide variety of diseases including chronic inflammation autoimmune diseases and cancer Cytokines are not only direct targets of therapeutics but also important biomarkers for assessing drug efficacy and safety Traditionally enzyme-linked immunosorbent assays ELISA were most popular for identifying and quantifying cytokines However ELISA is expensive labor intensive and low throughput Here we report the development of a miniaturized Luminex Austin TX assay platform to establish a panel of high-throughput multiplexed ... More
Cytokines serve as a major mechanism of communication between immune cells and are the functional molecules at the end of immune pathways. Abnormalities in cytokines are involved in a wide variety of diseases, including chronic inflammation, autoimmune diseases, and cancer. Cytokines are not only direct targets of therapeutics but also important biomarkers for assessing drug efficacy and safety. Traditionally, enzyme-linked immunosorbent assays (ELISA) were most popular for identifying and quantifying cytokines. However, ELISA is expensive, labor intensive, and low throughput. Here, we report the development of a miniaturized Luminex (Austin, TX) assay platform to establish a panel of high-throughput, multiplexed assays for measuring cytokines in human whole blood. The miniaturized 384-well Luminex assay uses <25% of the assay reagents compared with the 96-well assay. The development and validation of the 384-well Luminex cytokine assays enabled high-throughput screening of compounds in primary cells using cytokines as physiologically relevant readouts. Furthermore, this miniaturized multiplexed technology platform allows for high-throughput biomarker profiling of biofluids from animal studies and patient samples for translational research. Less
Live virus vaccines are a critical component of worldwide vaccination strategy for reducing disease burden but often require complex biological production processes that are sensitive to many different factors both known and often unknown Prior application of high throughput process development HTPD approaches to these processes has been hampered by a complex design space low throughput analytics and challenges inherent in biosafety level containment and asepsis in laboratory automation In we initiated a project with HighRes Biosolutions to design and install an integrated high throughput screening platform to enable HTPD for biosafety level upstream process development studies The system incorporates ... More
Live virus vaccines are a critical component of worldwide vaccination strategy for reducing disease burden but often require complex biological production processes that are sensitive to many different factors, both known and often unknown. Prior application of high‐throughput process development (HTPD) approaches to these processes has been hampered by a complex design space, low‐throughput analytics, and challenges inherent in biosafety level 2 containment and asepsis in laboratory automation. In 2013, we initiated a project with HighRes Biosolutions to design and install an integrated high‐throughput screening platform to enable HTPD for biosafety level 2 upstream process development studies. The system incorporates the necessary tools for performing cell and virus culture studies in microplates, as well as advanced analytical capabilities necessary for assessment of cell phenotype, product quality, and antigen yield. To date, we have applied this system to screen optimal media formulations and viral production conditions in support of two viral vaccine programs, with phenotypic assays performed as an integrated part of the workflow. This case study illustrates the power of HTPD in addressing large‐scale biological screening challenges by narrowing a vast design space and identifying parameter interactions in live virus production processes. Less
Catechol-O-methyltransferase COMT plays an important role in the deactivation of catecholamine neurotransmitters and hormones Inhibitors of COMT such as tolcapone and entacapone are used clinically in the treatment of Parkinson s disease Discovery of novel inhibitors has been hampered by a lack of suitable assays for high-throughput screening HTS Although assays using esculetin have been developed these are affected by fluorescence a common property of catechol-type compounds We have therefore evaluated a new homogenous time-resolved fluorescence HTRF based assay from CisBio Codolet France which measures the production of S-adenosyl-L-homocysteine SAH The assay has been run in both HTS and medium-throughput ... More
Catechol-O-methyltransferase (COMT) plays an important role in the deactivation of catecholamine neurotransmitters and hormones. Inhibitors of COMT, such as tolcapone and entacapone, are used clinically in the treatment of Parkinson’s disease. Discovery of novel inhibitors has been hampered by a lack of suitable assays for high-throughput screening (HTS). Although assays using esculetin have been developed, these are affected by fluorescence, a common property of catechol-type compounds. We have therefore evaluated a new homogenous time-resolved fluorescence (HTRF)–based assay from CisBio (Codolet, France), which measures the production of S-adenosyl-L-homocysteine (SAH). The assay has been run in both HTS and medium-throughput screening (MTS) modes. The assay was established using membranes expressing human membrane-bound COMT and was optimized for protein and time to give an acceptable signal window, good potency for tolcapone, and a high degree of translation between data in fluorescence ratio and data in terms of [SAH] produced. pIC50 values for the hits from the HTS mode were determined in the MTS mode. The assay also proved suitable for kinetic studies such as Km,app determination. Less
RNA binding proteins RBPs are involved in many cellular functions To facilitate functional characterization of RBPs we generated an RNA interference RNAi library for Drosophila cell-based screens comprising reagents targeting known or putative RBPs To test the quality of the library and provide a baseline analysis of the effects of the RNAi reagents on viability we screened the library using a total ATP assay and high-throughput imaging in Drosophila S R cultured cells The results are consistent with production of a high-quality library that will be useful for functional genomics studies using other assays Altogether we provide resources in the ... More
RNA binding proteins (RBPs) are involved in many cellular functions. To facilitate functional characterization of RBPs, we generated an RNA interference (RNAi) library for Drosophila cell-based screens comprising reagents targeting known or putative RBPs. To test the quality of the library and provide a baseline analysis of the effects of the RNAi reagents on viability, we screened the library using a total ATP assay and high-throughput imaging in Drosophila S2R+ cultured cells. The results are consistent with production of a high-quality library that will be useful for functional genomics studies using other assays. Altogether, we provide resources in the form of an initial curated list of Drosophila RBPs; an RNAi screening library we expect to be used with additional assays that address more specific biological questions; and total ATP and image data useful for comparison of those additional assay results with fundamental information such as effects of a given reagent in the library on cell viability. Importantly, we make the baseline data, including more than 200,000 images, easily accessible online. Less
The farnesoid X receptor FXR regulates the homeostasis of bile acids lipids and glucose Because endogenous chemicals bind and activate FXR it is important to examine which xenobiotic compounds would disrupt normal receptor function We used a cell-based human FXR -lactamase Bla reporter gene assay to profile the Tox K compound collection of environmental chemicals and drugs Structure-activity relationships of FXR-active compounds revealed by this screening were then compared against the androgen receptor estrogen receptor peroxisome proliferator-activated receptors and and the vitamin D receptor We identified several FXR-active structural classes including anthracyclines benzimidazoles dihydropyridines pyrethroids retinoic acids and vinca alkaloids ... More
The farnesoid X receptor (FXR) regulates the homeostasis of bile acids, lipids and glucose. Because endogenous chemicals bind and activate FXR, it is important to examine which xenobiotic compounds would disrupt normal receptor function. We used a cell-based human FXR β-lactamase (Bla) reporter gene assay to profile the Tox21 10K compound collection of environmental chemicals and drugs. Structure-activity relationships of FXR-active compounds revealed by this screening were then compared against the androgen receptor, estrogen receptor α, peroxisome proliferator-activated receptors δ and γ and the vitamin D receptor. We identified several FXR-active structural classes including anthracyclines, benzimidazoles, dihydropyridines, pyrethroids, retinoic acids and vinca alkaloids. Microtubule inhibitors potently decreased FXR reporter gene activity. Pyrethroids specifically antagonized FXR transactivation. Anthracyclines affected reporter activity in all tested assays, suggesting non-specific activity. These results provide important information to prioritize chemicals for further investigation and suggest possible modes of action of compounds in FXR signaling. Less