Small molecule inhibitors of bacterial secretion system

本申请描述了一个为期两年的研究学者发展计划，以确定和表征 铜绿假单胞菌III型分泌系统小分子抑制剂。长期目标是 在细菌病原体的相互作用方面建立一个高产和资金充足的研究计划， 宿主细胞利用本提案中概述的抑制剂。铜绿假单胞菌是一种机会致病菌， 革兰氏阴性菌医院感染的主要原因。导致这种病毒毒性的一个因素是 细菌是III型分泌系统。III型分泌系统是一种由20多种蛋白质组成的复合体， 允许将称为效应分子的蛋白质直接从细菌细胞质递送到细胞内， 真核宿主的细胞质。铜绿假单胞菌递送两种高度细胞毒性效应分子ExoS和 ExoU。这种毒素递送机制在许多细菌病原体中共享， 沙门氏菌、志贺氏菌、肠致病性E.大肠杆菌、衣原体和许多其他细菌。这种流行病 保守系统表明III型分泌是抑制以防止这些感染的理想靶点。 细菌病原体该提案旨在通过高通量测定来鉴定小分子抑制剂， 保护宿主细胞免受铜绿假单胞菌感染。保护性化合物将按 III型注射途径中的抑制步骤。与原始保护化合物相关的分子 将允许鉴定更有效的抑制剂。抑制剂对III型的生物学特异性 注射途径将在利用III型分泌系统的其他病原体中进行测试。而且有 抑制剂和III型分泌组分之间的直接联系将通过鉴定基因表达来确定。 每一类抑制剂的靶点。在这个提议中产生的工具可以用来剖析生物步骤 它们在许多利用III型分泌物来建立 感染.此外，在该提议中鉴定的小分子抑制剂可用作起始药物。 抑制由革兰氏阴性病原体引起的细菌感染的治疗方法的发展点 利用第三型分泌物。

This application describes a two-year research scholar development program to identify and characterize small molecular inhibitors of Pseudomonas aeruginosa type III secretion system. The long term goal is to establish a highly productive and well funded research program in the interaction of bacterial pathogens and host cells utilizing the inhibitors outlined in this proposal. P. aeruginosa is an opportunistic pathogen that is the leading cause of Gram-negative nosocomial infections. One factor that contributes to the virulence of this bacteria is the type III secretion system. Type III secretion system is a complex of over twenty proteins that allows for delivery of proteins called effector molecules directly from the bacterial cytoplasm into the cytoplasm of the eukaryotic host. P. aeruginosa delivers two highly cytotoxic effector molecules, ExoS and ExoU. This mechanism of toxin delivery is shared among many bacterial pathogens including Yersinia, Salmonella, Shigella, enteropathogenic E. coli, Chlamydia and many others. The prevalence of this conserved system suggests that type III secretion is an ideal target for inhibition to prevent infection by these bacterial pathogens. This proposal aims to identify small molecular inhibitors by a high-throughput assay that measures protection of host cells to infection by P. aeruginosa. Protective compounds will be classified by the inhibitory step in the type III injection pathway. Related molecules to the original protective compounds will allow identification of more potent inhibitors. The biological specificity of the inhibitors on the type III injection pathway will be tested in other pathogens that utilize type III secretion systems. Furthermore, a direct link between the inhibitor and type III secretion component will be made by identification of the genetic target of each class of inhibitors. The tools generated in this proposal can be used to dissect biological steps that are shared or distinct between a number of bacterial pathogens that utilize type III secretion to establish infections. Furthermore, the small molecule inhibitors identified in this proposal may be used as a starting point for the development of theraputics to inhibit bacterial infection caused by Gram-negative pathogens that utilize type III seceretion.