MAPK-mediated defense pathways against pore-forming toxins

描述（由申请人提供）：本申请的主要目的是了解宿主细胞如何防御病原菌产生的成孔毒素。长期目标是利用这些信息开发新的治疗方法，通过增强细胞对成孔毒素的防御来保护人类免受细菌感染。孔形成毒素是细菌毒力因子中最大的单一组，占细菌产生的所有蛋白质毒素的>25%。它们对于人类的许多主要细菌病原体（包括金黄色葡萄球菌和链球菌）的体内毒力是重要的。秀丽隐杆线虫已成为研究动物细胞如何以与哺乳动物相关的方式防御孔形成毒素的重要的遗传学上易处理的体内系统。c-JUN N末端激酶（JNK）丝裂原活化蛋白激酶（MAPK）是C. elegans，调节所有PFT诱导的防御的一半。具体目标我将使用正向和反向遗传学，遗传和生化测试，定量中毒分析，并表达分析，以组装尽可能完整的C。线虫JNK PFT诱导的防御途径，朝向JNK上游朝向初始孔形成和JNK下游进入调节的防御子途径。具体目标II涉及使用与医学相关的成孔毒素处理的哺乳动物细胞，以确定C。线虫的防御在哺乳动物细胞中是保守的。Specific Aim III使用了一套独特而强大的C. elegans研究JNK PFT诱导的防御途径保护细胞免受PFT攻击的实际机制。Specific Aim III的另一个目标是揭示PFT防御的新细胞机制。 公共卫生相关性：在感染过程中，许多致病细菌分泌成孔毒素，在细胞膜上穿孔，作为破坏和破坏我们细胞的一种手段。在这个应用程序中，我们将研究我们的细胞如何反击并保护自己免受这些毒素的侵害。我们的目标是利用这些信息来设计新的药物，增强我们对细菌毒素和疾病的防御。

DESCRIPTION (provided by applicant): The broad objective of this application is to understand how host cells defend themselves against pore-forming toxins made by pathogenic bacteria. The long term objective is to use this information for development of novel therapeutics that protects humans against bacterial infection by boosting cellular defenses against pore-forming toxins. Pore-forming toxins are the largest single group of bacterial virulence factors, comprising >25% of all protein toxins made by bacteria. They are important for the in vivo virulence of many major bacterial pathogens of humans, including Staphylococcus aureus and Streptococci. Caenorhabditis elegans has emerged as an important genetically-tractable in vivo system for studying how animal cells defend against pore-forming toxins in a manner relevant to mammals. c-JUN N-terminal Kinase (JNK) mitogen-activated protein kinase (MAPK) is a central regulator of induced cellular defenses to pore-forming toxins in C. elegans, regulating half of all PFT-induced defenses. Specific Aim I will use forward and reverse genetics, genetic and biochemical tests, quantitative intoxication assays, and expression analyses to assemble as completely as possible the C. elegans JNK PFT-induced defense pathway, heading both upstream of JNK towards initial pore-formation and downstream of JNK into regulated defense subpathways. Specific Aim II involves the use of mammalian cells treated with a medically relevant pore-forming toxin to ascertain how well C. elegans defenses are conserved in mammalian cells. Specific Aim III uses a unique and powerful set of assays developed in C. elegans to study the actual mechanisms by which the JNK PFT-induced defense pathway protects cells against PFT attack. An additional goal of Specific Aim III is to uncover new cellular mechanisms for PFT defenses. PUBLIC HEALTH RELEVANCE: During infection, many disease-causing bacteria secrete pore-forming toxins that punch holes in cell membranes as a means towards damaging and disabling our cells. In this application, we will study how our cells fight back and protect themselves against these toxins. Our goal is to use this information to design new drugs that boost our own defenses against bacterial toxins and disease.