Identifying the formate-sensory mechanism in Shigella flexneri

鉴定福氏志贺氏菌的甲酸感觉机制

基本信息

批准号：
10428655
负责人：
Benjamin J. Koestler
金额：
$ 7.55万
依托单位：
WESTERN MICHIGAN UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-14 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10428655
关键词：
Acetyl Coenzyme A Acids Acute Address Antimicrobial Resistance Binding Proteins Biological Assay Blood capillaries Cell Density Cells Cessation of life Colon Critical Pathways Cues Cytoplasm Defect Disease Dysentery Enterobacteriaceae Environment Epithelial Epithelial Cells Escherichia coli Expression Library Fermentation Future Gastrointestinal tract structure Gene Expression Genes Genetic Screening Genetic Transcription Glycolysis Goals Growth Host Defense Human Human body Immune response Immunosuppression Incidence Infection Inflammation Ingestion Invaded Libraries Ligands Liquid substance Lyase Metabolism Modeling Molecular Morbidity - disease rate Multi-Drug Resistance Pathogenesis Pathogenicity Population Prevention Production Promoter Regions Public Health Pyruvate Radial Regulation Reporter Research Role Shigella Shigella Infections Shigella Vaccines Shigella flexneri Signal Transduction System Vaccines Virulence antimicrobial diarrheal disease extracellular human pathogen insight monolayer mortality mutant novel pathogen programs response sensory mechanism spatiotemporal therapeutic development transcriptome sequencing vaccine development

项目摘要

Abstract The enteric bacteria and intracellular human pathogen Shigella causes hundreds of millions of cases of the diarrheal disease shigellosis (dysentery) per year worldwide and as many as one million deaths. Currently, there is no approved vaccine for the prevention of shigellosis, and the incidence of antimicrobial resistance amongst Shigella spp. is on the rise. To cause disease, Shigella flexneri is ingested into a human host, and then migrates through the digestive tract and invades colonic epithelial cells where it replicates and causes acute inflammation; this pathogenesis requires a coordinated program of virulence gene expression for S. flexneri to adapt to different host environments and states. Even within a host epithelial cell, S. flexneri virulence gene expression is dynamic, and one signal that S. flexneri uses to regulate this expression is its own production of formate. As S. flexneri replicates within a host cell, it produces and secretes formate, a byproduct of mixed acid fermentation, and this formate accumulates in the host cell. S. flexneri then senses this formate accumulation to positively regulate the expression of virulence genes associated with intercellular spread and dampening the host immune response; however, the mechanism by which S. flexneri recognizes formate accumulation within a host cell is unknown. The goal of this study is to identify the S. flexneri system used to sense extracellular formate accumulation in the host cell cytoplasm during pathogenesis. The first aim of this proposal is to use the differential radial capillary action of ligand assay (DRaCALA) to identify S. flexneri formate binding proteins, and then characterize their role in promoting S. flexneri plaque formation. The second aim of this proposal is to perform a genetic screen of a S. flexneri transposon mutant library to identify genes associated with the S. flexneri response to formate. Identifying this important virulence regulatory system will enable future studies to characterize the dynamics of formate signaling in infected host cells, and potentially provide novel targets for antimicrobial therapeutics and vaccine development.

抽象的肠细菌和细胞内人类病原体志贺氏菌引起了数亿例腹泻病shigellosis（痢疾）每年在全球范围内，多达100万人死亡。现在，没有批准的疫苗用于预防志核病，抗菌素耐药性的发生率在Shigella spp中。正在上升。为了引起疾病，Shigella Flexneri被摄入到人类宿主中，并且然后通过消化道迁移，并入侵结肠上皮细胞，并在其中复制并引起原因急性炎症；这种发病机理需要一个协调的S.毒力基因表达程序。灵活地适应不同的主机环境和状态。即使在宿主上皮细胞中，S。flexneri 毒力基因表达是动态的，而S. flexneri用来调节该表达的一个信号是它自己的生产甲酸。随着S. flexneri在宿主单元中复制，它会产生和分泌甲酸，副产品混合酸发酵，该构造积聚在宿主细胞中。 S. flexneri然后感觉到这个构造积累以积极调节与细胞间扩散相关的毒力基因的表达和抑制宿主免疫反应；但是，S。Flexneri识别甲酸的机制宿主细胞内的积累尚不清楚。这项研究的目的是确定曾经的S. flexneri系统在发病机理期间，有义宿主细胞细胞质中的细胞外甲酸盐积累。第一个目的建议是使用配体分析（Dracala）的差分径向毛细管作用来识别链球菌构造结合蛋白，然后表征其在促进柔性斑块形成中的作用。第二个该提议的目的是执行S. flexneri转座子突变库的遗传筛选以识别基因与S. flexneri对甲酸盐的响应有关。确定这种重要的毒力调节系统将使未来的研究能够表征受感染宿主细胞中甲酸的动力传导的动力学，并有可能为抗菌治疗和疫苗开发提供新的靶标。