High-throughput Screening Technologies Research Articles

Abstract 1069: MiR-21 may serve as a predictive biomarker of response in the assessment of efficacy of HSP-90 inhibition in gastrointestinal (GI) cancers

Abstract Background and Aims: MicroRNAs mediate drug resistance and are often deregulated in cancer with miR-21 upregulation being shared across different gastrointestinal (GI) cancers. In this study we aim to identify small drugs for which miR-21 may be considered a biomarker of sensitivity. Methods: High throughput screening technologies (HST) was applied in RKO colorectal cancer (CRC) cells engineered to knock out miR-21 locus (miR-21KO) and parental isogenic wild type (WT) cells, as well as 6 Biliary Tract Cancer (BTC) cell lines that were NGSed for a panel of 64 genes. Library included 484 small molecules that were screened at 3 doses against each cell line in triplicate. Transient miR-21 inhibition was achieved by reverse transfection. Stable doxycycline-activated miR-21 expressing clones of BTC and CRC cells were generated with doxycycline-inducible TRIPZ lentiviral vectors. Results: Twenty four drugs reduced cell viability compared to DMSO at a greater extent in miR-21KO RKO in comparison to WT cells. Enrichment in HSP-90 inhibitors (including 17-DMAG, 17-AAG and AUY-922) was noticed, suggesting that miR-21 may be involved in resistance to HSP-90 inhibition. HST in BTC cells showed enrichment of HSP-90 inhibitors independently on mutational status. However IC50 to AUY-922 was correlated to baseline miR-21 expression in BTC cells. Transient inhibition of miR-21 enhanced sensitivity to AUY-922 in BTC cells. AUY-922 IC50 was 35nM for WT and 17nM for miR-21KO RKO cells. Knock-out of miR-21 in DLD-1 cells did not change sensitivity to AUY-922 in line with the lower baseline levels of miR-21 in DLD-1 wild type cells. However, the reduced levels of baseline miR-21 made them more sensitive to AUY-922 than RKO. Doxycycline-activated overexpression of miR-21 in miR-21KO DLD-1 cells conferred resistance to AUY-922. When co-cultured with non-infected miR-21KO DLD-1 cells, miR-21 overexpressing miR-21KO DLD-1 cells were able to drive cell growth in presence of AUY-922. To similar extent CCLP with enforced expression of miR-21 were more resistant compared to control cells; inactivation of the induction of miR-21 overexpression recovered sensitivity to the drug. HSP Array blot of AUY-922-treated cells with induced expression of miR-21 showed reduction of the co-chaperone HSP-40 protein expression compared to control cells. Conclusions: Our data suggest the development of studies looking at the biomarker potential of miR-21 to guide treatment with HSP-90 inhibitors in GI cancers, as well as pursuing the combination with miR-21 inhibitors that may enhance the effect of the drug and avoid toxicity by enabling dose reduction. Citation Format: Andrea Lampis, Luciano Cascione, Rosemary Burke, Paul Clarke, Michele Simbolo, Aldo Scarpa, Else Bosma, Sijia Yu, Rebecca Cole, Mark Stubbs, Swee Sharp, Rob Van Montfort, Jens C. Hahne, Matteo Fassan, Paul Workman, Nicola Valeri, Chiara Braconi. MiR-21 may serve as a predictive biomarker of response in the assessment of efficacy of HSP-90 inhibition in gastrointestinal (GI) cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1069.

Abstract 2228: Cbl-b inhibitors as novel intra-cellular checkpoint inhibitors for cancer immunotherapy

Abstract The approval by the FDA and clinical use of immune checkpoint inhibitors, such as anti-PD1 and anti-CTLA4 antibodies, that activate cytotoxic T lymphocyte (CTL) mediated anti-tumor immune responses against advanced solid tumors has resulted in a paradigm shift in cancer therapy. Antitumor activity of CTLs and NK cells is tightly regulated by intracellular signaling events orchestrated by the ubiquitin signaling system. In particular, Cbl-b (Casitas B-lineage lymphoma proto-oncogene b), a RING finger E3-ubiquitin ligase primarily expressed in immune cells, acts as an intracellular checkpoint and a master negative regulator of both CTLs and NK cells. Accordingly, Cbl-b-/- mice have been observed to reject a variety of implanted metastatic and non-metastatic tumors and to delay significantly the outgrowth of spontaneous tumors; these observed antitumor effects were seen to be mediated by activated CD8+ T cells and NK cells. Based on the overwhelming evidence supporting the role of Cbl-b in immune suppression, this ubiquitin conjugating enzyme is considered a novel target for developing small molecule cancer immunotherapy agents. Using proprietary high throughput screening technologies, Progenra identified novel, selective Cbl-b inhibitors that were shown to decrease ubiquitination of substrates such as TAM receptor kinases (Tyro3) and to activate T cells (as judged by increased IL-2 production) and NK cells (as judged by increased IFNγ production and degranulation) in ex vivo functional assays. ADME/DMPK evaluation and in vivo efficacy of selected Cbl-b inhibitors will be discussed in relation to the therapeutic utility of this class of small molecule agent, which is expected to potentiate the anticancer effects of approved immunotherapy agents. Citation Format: Saket Agarwal, Jian Wu, Chris Riling, Matthew Kodrasov, Joseph Weinstock, Ivan Sokirniy, Michael Mattern, Taku Kambayashi, Suresh Kumar. Cbl-b inhibitors as novel intra-cellular checkpoint inhibitors for cancer immunotherapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2228.

Using In Vitro High-Throughput Screening Data for Predicting Benzo[k]Fluoranthene Human Health Hazards.

Today there are more than 80,000 chemicals in commerce and the environment. The potential human health risks are unknown for the vast majority of these chemicals as they lack human health risk assessments, toxicity reference values, and risk screening values. We aim to use computational toxicology and quantitative high-throughput screening (qHTS) technologies to fill these data gaps, and begin to prioritize these chemicals for additional assessment. In this pilot, we demonstrate how we were able to identify that benzo[k]fluoranthene may induce DNA damage and steatosis using qHTS data and two separate adverse outcome pathways (AOPs). We also demonstrate how bootstrap natural spline-based meta-regression can be used to integrate data across multiple assay replicates to generate a concentration-response curve. We used this analysis to calculate an in vitro point of departure of 0.751 μM and risk-specific in vitro concentrations of 0.29 μM and 0.28 μM for 1:1,000 and 1:10,000 risk, respectively, for DNA damage. Based on the available evidence, and considering that only a single HSD17B4 assay is available, we have low overall confidence in the steatosis hazard identification. This case study suggests that coupling qHTS assays with AOPs and ontologies will facilitate hazard identification. Combining this with quantitative evidence integration methods, such as bootstrap meta-regression, may allow risk assessors to identify points of departure and risk-specific internal/in vitro concentrations. These results are sufficient to prioritize the chemicals; however, in the longer term we will need to estimate external doses for risk screening purposes, such as through margin of exposure methods.

A Replicative In Vitro Assay for Drug Discovery against Leishmania donovani.

The protozoan parasite Leishmania donovani is the causative agent of visceral leishmaniasis, a disease potentially fatal if not treated. Current available treatments have major limitations, and new and safer drugs are urgently needed. In recent years, advances in high-throughput screening technologies have enabled the screening of millions of compounds to identify new antileishmanial agents. However, most of the compounds identified in vitro did not translate their activities when tested in in vivo models, highlighting the need to develop more predictive in vitro assays. In the present work, we describe the development of a robust replicative, high-content, in vitro intracellular L. donovani assay. Horse serum was included in the assay media to replace standard fetal bovine serum, to completely eliminate the extracellular parasites derived from the infection process. A novel phenotypic in vitro infection model has been developed, complemented with the identification of the proliferation of intracellular amastigotes measured by EdU incorporation. In vitro and in vivo results for miltefosine, amphotericin B, and the selected compound 1 have been included to validate the assay.

High‐throughput cell quantification assays for use in cell purification development – enabling technologies for cell production

High-throughput screening (HTS) technology is gaining increasing importance in downstream process development of cell-based products. The development of such HTS-technologies, however, is highly dependent on the availability of robust, accurate, and sensitive high-throughput cell quantification methods. In this article, we compare state-of-the-art cell quantification methods with focus on their applicability in HTS-platforms for downstream processing of cell-based products. Sensitivity, dynamic range, and precision were evaluated for four methods that differ in their respective mechanism. In addition, we evaluated the performance of these methods over a range of buffer compositions, medium densities, and viscosities, representing conditions found in many downstream processing methods. We found that CellTiter-Glo™ and flow cytometry are excellent tools for high-throughput cell quantification. Both methods have broad working ranges (3-4 log) and performed well over a wide range of buffer compositions. In comparison, CyQuant® Direct and CellTracker™ had smaller working ranges and were more sensitive to changes in buffer composition. For fast and sensitive quantification of a single cell type, CellTiter-Glo™ performed best, while for more complex cell mixtures flow cytometry is the method of choice. Our analysis will facilitate the selection of the most suitable method for a specific application and provides a benchmark for future HTS development in downstream processing of cell-based products.

Automated Gravimetric Calibration to Optimize the Accuracy and Precision of TECAN Freedom EVO Liquid Handler.

High-throughput screening technologies are increasingly integrated into the formulation development process of biopharmaceuticals. The performance of liquid handling systems is dependent on the ability to deliver accurate and precise volumes of specific reagents to ensure process quality. We have developed an automated gravimetric calibration procedure to adjust the accuracy and evaluate the precision of the TECAN Freedom EVO liquid handling system. Volumes from 3 to 900 µL using calibrated syringes and fixed tips were evaluated with various solutions, including aluminum hydroxide and phosphate adjuvants, β-casein, sucrose, sodium chloride, and phosphate-buffered saline. The methodology to set up liquid class pipetting parameters for each solution was to split the process in three steps: (1) screening of predefined liquid class, including different pipetting parameters; (2) adjustment of accuracy parameters based on a calibration curve; and (3) confirmation of the adjustment. The run of appropriate pipetting scripts, data acquisition, and reports until the creation of a new liquid class in EVOware was fully automated. The calibration and confirmation of the robotic system was simple, efficient, and precise and could accelerate data acquisition for a wide range of biopharmaceutical applications.

Introducing Discrete Frequency Infrared Technology for High-Throughput Biofluid Screening.

Accurate early diagnosis is critical to patient survival, management and quality of life. Biofluids are key to early diagnosis due to their ease of collection and intimate involvement in human function. Large-scale mid-IR imaging of dried fluid deposits offers a high-throughput molecular analysis paradigm for the biomedical laboratory. The exciting advent of tuneable quantum cascade lasers allows for the collection of discrete frequency infrared data enabling clinically relevant timescales. By scanning targeted frequencies spectral quality, reproducibility and diagnostic potential can be maintained while significantly reducing acquisition time and processing requirements, sampling 16 serum spots with 0.6, 5.1 and 15% relative standard deviation (RSD) for 199, 14 and 9 discrete frequencies respectively. We use this reproducible methodology to show proof of concept rapid diagnostics; 40 unique dried liquid biopsies from brain, breast, lung and skin cancer patients were classified in 2.4 cumulative seconds against 10 non-cancer controls with accuracies of up to 90%.

Fluorescence imaging technology (FI) for high-throughput screening of selenide-modified nano-TiO2 catalysts.

A high-throughput screening (HTS) method based on fluorescence imaging (FI) was implemented to evaluate the catalytic performance of selenide-modified nano-TiO2. Chemical ink-jet printing (IJP) technology was reformed to fabricate a catalyst library comprising 1405 (Ni(a)Cu(b)Cd(c)Ce(d)In(e)Y(f))Se(x)/TiO2 (M6Se/Ti) composite photocatalysts. Nineteen M6Se/Tis were screened out from the 1405 candidates efficiently.

Tuber metabolic profiling of resistant and susceptible potato varieties challenged with Phytophthora infestans

Selection of disease resistant potato varieties for conventional breeders is a time consuming and labor intensive process and most of the times lead to the results that are spatiotemporally inconsistent. Metabolic phenotyping was employed to develop metabolic criteria that can be used to distinguish potato genotypes with disease resistance. Tubers of potato varieties (Caesar and AC Novachip) moderately resistant and susceptible to Phytophthora infestans were inoculated with pathogen or water, and metabolites were analyzed using Gas Chromatography-mass Spectrometry (GS/MS). Disease severity was measured as the volume of diseased tissue calculated based on lesions volume at 2-day intervals after inoculation. Disease severity was 4.17 and 0.61 cm3 for varieties Caesar and AC Novachip respectively. Seventy seven metabolites were tentatively identified using Automated Mass spectral Deconvolution and Identification System (AMDIS) and univariate ANOVA showed that 37 metabolites had significant treatment effects with nine identified as resistance related and five as constitutive metabolites. Four metabolites, constitutive or induced showed significant increase in their abundance in pathogen inoculated tubers. A total of 21 metabolites were considered as pathogenesis related which showed changes in abundance after pathogen challenge. A canonical discriminant analysis of the 37 metabolites identified metabolic phenotypes correlating to disease severity phenotypes. The metabolites were mainly from sugars, fatty acids, and phenolic compounds which of some may have potential antimicrobial activity. Among resistance related metabolites, the abundances of 1H-Indole-3-acetonitrile, trihydroxybutyrate, D-Mannitol, dihydocoumarin, and propanoate were significantly higher in Caesar. The potential application of metabolic profiling technology for high throughput screening of potato breeding lines against potato late blight is discussed.

High throughput screening technologies for ion channels.

Ion channels are involved in a variety of fundamental physiological processes, and their malfunction causes numerous human diseases. Therefore, ion channels represent a class of attractive drug targets and a class of important off-targets for in vitro pharmacological profiling. In the past decades, the rapid progress in developing functional assays and instrumentation has enabled high throughput screening (HTS) campaigns on an expanding list of channel types. Chronologically, HTS methods for ion channels include the ligand binding assay, flux-based assay, fluorescence-based assay, and automated electrophysiological assay. In this review we summarize the current HTS technologies for different ion channel classes and their applications.

IRDA: a new filter towards predictive, stable, and enriched candidate genes.

BackgroundGene expression profiling using high-throughput screening (HTS) technologies allows clinical researchers to find prognosis gene signatures that could better discriminate between different phenotypes and serve as potential biological markers in disease diagnoses. In recent years, many feature selection methods have been devised for finding such discriminative genes, and more recently information theoretic filters have also been introduced for capturing feature-to-class relevance and feature-to-feature correlations in microarray-based classification.MethodsIn this paper, we present and fully formulate a new multivariate filter, iRDA, for the discovery of HTS gene-expression candidate genes. The filter constitutes a four-step framework and includes feature relevance, feature redundancy, and feature interdependence in the context of feature-pairs. The method is based upon approximate Markov blankets, information theory, several heuristic search strategies with forward, backward and insertion phases, and the method is aiming at higher order gene interactions.ResultsTo show the strengths of iRDA, three performance measures, two evaluation schemes, two stability index sets, and the gene set enrichment analysis (GSEA) are all employed in our experimental studies. Its effectiveness has been validated by using seven well-known cancer gene-expression benchmarks and four other disease experiments, including a comparison to three popular information theoretic filters. In terms of classification performance, candidate genes selected by iRDA perform better than the sets discovered by the other three filters. Two stability measures indicate that iRDA is the most robust with the least variance. GSEA shows that iRDA produces more statistically enriched gene sets on five out of the six benchmark datasets.ConclusionsThrough the classification performance, the stability performance, and the enrichment analysis, iRDA is a promising filter to find predictive, stable, and enriched gene-expression candidate genes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2129-5) contains supplementary material, which is available to authorized users.

Integrated HPTLC-based methodology for the tracing of bioactive compounds in herbal extracts by employing multivariate chemometrics. The case study of anti-tyrosinase agents from Morus alba

The contribution of naturally derived products for drug discovery purposes is undisputed. The implementation of high-throughput screening (HTS) technologies has allowed the rapid and effective investigation of the chemical composition and pharmacological properties of a large number of plant extracts against several biological targets. The scope of this study was the discovery of plant derived tyrosinase inhibitors utilizing a HTS approach and the introduction of an integrated methodology for the rapid identification of bioactive compounds during bioassay-guided procedures.

Flow-Based Single Cell Deposition for High-Throughput Screening of Protein Libraries.

The identification and engineering of proteins having refined or novel characteristics is an important area of research in many scientific fields. Protein modelling has enabled the rational design of unique proteins, but high-throughput screening of large libraries is still required to identify proteins with potentially valuable properties. Here we report on the development and evaluation of a novel fluorescent activated cell sorting based screening platform. Single bacterial cells, expressing a protein library to be screened, are electronically sorted and deposited onto plates containing solid nutrient growth media in a dense matrix format of between 44 and 195 colonies/cm2. We show that this matrix format is readily applicable to machine interrogation (<30 seconds per plate) and subsequent bioinformatic analysis (~60 seconds per plate) thus enabling the high-throughput screening of the protein library. We evaluate this platform and show that bacteria containing a bioluminescent protein can be spectrally analysed using an optical imager, and a rare clone (0.5% population) can successfully be identified, picked and further characterised. To further enhance this screening platform, we have developed a prototype electronic sort stream multiplexer, that when integrated into a commercial flow cytometric sorter, increases the rate of colony deposition by 89.2% to 24 colonies per second. We believe that the screening platform described here is potentially the foundation of a new generation of high-throughput screening technologies for proteins.

A Bead-Based Proximity Assay for BRD4 Ligand Discovery.

Bromodomain-containing proteins have emerged as desirable targets for anti-neoplastic and anti-inflammatory drug discovery. Toward the development of selective inhibitors of the BET family of bromodomains, we optimized bead-based assays to detect interactions between bromodomains and poly-acetylated histone peptides. Donor and acceptor beads bound to target and ligand are brought into proximity by this protein-protein interaction. After laser illumination, singlet oxygen evolved from donor beads travels to the spatially close acceptor beads, resulting in chemiluminesence. This AlphaScreen assay has proven amendable to high-throughput screening, secondary validation, and specificity profiling during lead discovery and optimization. Here we report our protocol for assay development to measure inhibition of ligand binding to bromodomain-containing protein 4 (BRD4). We discuss the discovery of an appropriate probe, optimization of bead, probe, and protein concentrations, and the derivation of protein-probe inhibition curves. Finally, we explore the implementation of this technology for high-throughput screening of potential BRD4 inhibitors.

A high-throughput liquid bead array-based screening technology for Bt presence in GMO manipulation.

The number of species and planting areas of genetically modified organisms (GMOs) has been rapidly developed during the past ten years. For the purpose of GMO inspection, quarantine and manipulation, we have now devised a high-throughput Bt-based GMOs screening method based on the liquid bead array. This novel method is based on the direct competitive recognition between biotinylated antibodies and beads-coupled antigens, searching for Bt presence in samples if it contains Bt Cry1 Aa, Bt Cry1 Ab, Bt Cry1 Ac, Bt Cry1 Ah, Bt Cry1 B, Bt Cry1 C, Bt Cry1 F, Bt Cry2 A, Bt Cry3 or Bt Cry9 C. Our method has a wide GMO species coverage so that more than 90% of the whole commercialized GMO species can be identified throughout the world. Under our optimization, specificity, sensitivity, repeatability and availability validation, the method shows a high specificity and 10-50 ng/mL sensitivity of quantification. We then assessed more than 1800 samples in the field and food market to prove capacity of our method in performing a high throughput screening work for GMO manipulation. Our method offers an applicant platform for further inspection and research on GMO plants.

Magnetic Alignment of Microelements Containing Cultured Neuronal Networks for High-Throughput Screening

High-throughput screening (HTS) on neurons presents unique difficulties because they are postmitotic, limited in supply, and challenging to harvest from animals or generate from stem cells. These limitations have hindered neurological drug discovery, leaving an unmet need to develop cost-effective technology for HTS using neurons. Traditional screening methods use up to 20,000 neurons per well in 384-well plates. To increase throughput, we use “microraft” arrays, consisting of 1600 square, releasable, paramagnetic, polystyrene microelements (microrafts), each providing a culture surface for 500–700 neurons. These microrafts can be detached from the array and transferred to 384-well plates for HTS; however, they must be centered within wells for automated imaging. Here, we developed a magnet array plate, compatible with HTS fluid-handling systems, to center microrafts within wells. We used finite element analysis to select an effective size of the magnets and confirmed that adjacent magnetic fields do not interfere. We then experimentally tested the plate’s centering ability and found a centering efficiency of 100%, compared with 4.35% using a flat magnet. We concluded that microrafts could be centered after settling randomly within the well, overcoming friction, and confirmed these results by centering microrafts containing hippocampal neurons cultured for 8 days.

High-Throughput Intracellular Antimicrobial Susceptibility Testing of Legionella pneumophila

Legionella pneumophila is a Gram-negative opportunistic human pathogen that causes a severe pneumonia known as Legionnaires' disease. Notably, in the human host, the organism is believed to replicate solely within an intracellular compartment, predominantly within pulmonary macrophages. Consequently, successful therapy is predicated on antimicrobials penetrating into this intracellular growth niche. However, standard antimicrobial susceptibility testing methods test solely for extracellular growth inhibition. Here, we make use of a high-throughput assay to characterize intracellular growth inhibition activity of known antimicrobials. For select antimicrobials, high-resolution dose-response analysis was then performed to characterize and compare activity levels in both macrophage infection and axenic growth assays. Results support the superiority of several classes of nonpolar antimicrobials in abrogating intracellular growth. Importantly, our assay results show excellent correlations with prior clinical observations of antimicrobial efficacy. Furthermore, we also show the applicability of high-throughput automation to two- and three-dimensional synergy testing. High-resolution isocontour isobolograms provide in vitro support for specific combination antimicrobial therapy. Taken together, findings suggest that high-throughput screening technology may be successfully applied to identify and characterize antimicrobials that target bacterial pathogens that make use of an intracellular growth niche.

Osteogenic programs during zebrafish fin regeneration.

Recent advances in genomic, screening and imaging technologies have provided new opportunities to examine the molecular and cellular landscape underlying human physiology and disease. In the context of skeletal research, technologies for systems genetics, high-throughput screening and high-content imaging can aid an unbiased approach when searching for new biological, pathological or therapeutic pathways. However, these approaches necessitate the use of specialized model systems that rapidly produce a phenotype, are easy to manipulate, and amenable to optical study, all while representing mammalian bone physiologies at the molecular and cellular levels. The emerging use of zebrafish (Danio rerio) for modeling human disease highlights its potential to accelerate therapeutic and pathway discovery in the mammalian skeleton. In this review, we consider the potential value of zebrafish fin ray regeneration (a rapid, genetically tractable and optically transparent model of intramembranous ossification) as a translational model for such studies.

Computational Analysis and In silico Predictive Modeling for Inhibitors of PhoP Regulon in S. typhi on High-Throughput Screening Bioassay Dataset.

There is emergence of multidrug-resistant Salmonella enterica serotype typhi in pandemic proportions throughout the world, and therefore, there is a necessity to speed up the discovery of novel molecules having different modes of action and also less influenced by the resistance formation that would be used as drug for the treatment of salmonellosis particularly typhoid fever. The PhoP regulon is well studied and has now been shown to be a critical regulator of number of gene expressions which are required for intracellular survival of S. enterica and pathophysiology of disease like typhoid. The evident roles of two-component PhoP-/PhoQ-regulated products in salmonella virulence have motivated attempts to target them therapeutically. Although the discovery process of biologically active compounds for the treatment of typhoid relies on hit-finding procedure, using high-throughput screening technology alone is very expensive, as well as time consuming when performed on large scales. With the recent advancement in combinatorial chemistry and contemporary technique for compounds synthesis, there are more and more compounds available which give ample growth of diverse compound library, but the time and endeavor required to screen these unfocused massive and diverse library have been slightly reduced in the past years. Hence, there is demand to improve the high-quality hits and success rate for high-throughput screening that required focused and biased compound library toward the particular target. Therefore, we still need an advantageous and expedient method to prioritize the molecules that will be utilized for biological screens, which saves time and is also inexpensive. In this concept, in silico methods like machine learning are widely applicable technique used to build computational model for high-throughput virtual screens to prioritize molecules for advance study. Furthermore, in computational analysis, we extended our study to identify the common enriched structural entities among the biologically active compound toward finding out the privileged scaffold.

Developing a high-throughput screening method for threonine overproduction based on an artificial promoter.

Backgroundl-Threonine is an important amino acid for animal feed. Though the industrial fermentation technology of threonine achieved a very high level, there is still significant room to further improve the industrial strains. The biosensor-based high-throughput screening (HTS) technology has demonstrated its powerful applications. Unfortunately, for most of valuable fine chemicals such as threonine, a HTS system has not been established mainly due to the absence of a suitable biosensor. In this study, we developed a HTS method to gain high-yielding threonine-producing strains.ResultsNovel threonine sensing promoters including cysJp and cysHp were discovered by proteomic analyses of Escherichia coli in response to extracellular threonine challenges. The HTS method was constructed using a device composed of the fused cysJp and cysHp as a promoter and a linked enhanced green fluorescent protein gene as a reporter. More than 400 strains were selected with fluorescence activated cell sorting technology from a library of 20 million mutants and tested within 1 week. Thirty-four mutants have higher productivities than the starting industrial producer. One mutant produced 17.95 % more threonine in a 5-L jar fermenter.ConclusionsThis method should play a functional role for continuous improvement of threonine industry. Additionally, the threonine sensor construction using promoters obtained by proteomics analyses is so convenient that it would be easily extended to develop HTS models for other biochemicals.