海洋弧菌T3SS的分子多样性及其与毒力的关联分析

项目名称： 海洋弧菌T3SS的分子多样性及其与毒力的关联分析

项目编号： No.41276163

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 赵哲

作者单位： 中国科学院南海海洋研究所

项目金额： 76万元

中文摘要： 海洋弧菌是海洋环境中最常见的细菌类群之一，但部分种类是人和海洋动物的重要病原菌，故其毒力差异的机制备受关注。三型分泌系统(T3SS)是许多病原细菌中保守存在的毒力装置，通过分泌效应蛋白直接参与病原菌的致病过程，但不同病原菌之间的效应蛋白存在较大差异。本项目旨在研究不同海洋弧菌之间在T3SS效应蛋白编码上的多样性及其与毒力的关系。拟首先通过PCR技术系统调查T3SS在不同海洋弧菌中的存在情况，然后采用染色体步移技术测定不同海洋弧菌在T3SS效应蛋白编码区的序列，查明海洋弧菌T3SS编码效应蛋白的多样性；进一步利用基于pDM4自杀质粒的基因敲除技术，构建不同海洋弧菌T3SS的效应蛋白基因缺失突变株，并用以重点研究效应蛋白的多样性对其致宿主细胞死亡的影响；并借助实验动物感染模型，最终阐明不同海洋弧菌的T3SS效应蛋白多样性与其毒力的关系；研究结果对于揭示不同海洋弧菌在毒力上的差异机制具有重要意义

中文关键词： 弧菌；三型分泌系统；效应蛋白；多样性；毒力

英文摘要： Marine Vibrios are the most common bacteria that are widespread in the coastal and estuarine environments, some species of them, however, are recognized as opportunistic pathogens to both marine animals and humans. So many attentions have been paid on virulence differences of marine Vibrios. Type III secretion system (T3SS) is a highly-conserved apparatus among several gram-negative bacteria, which delivers bacterial virulence proteins, called effectors, into host cells and is directly involved in pathogenesis of bacteria. However, the effectors vary significantly from system to system, even within families of T3SS. In this study, we focus on the molecular diversity of T3SS in marine Vibrios and then explore its relevance to virulence of marine Vibrios. To this end, first, we systematically examine the distribution of T3SS in different marine Vibrios using PCR assay, and then determine the genomic sequence in the hypothetical regions encoding effectors of the T3SS using chromosome walking, and ascertain molecular diversity of the effectors of T3SS in different marine Vibrios. Importantly, we respectively construct the null mutants of structural protein and effector protein genes of T3SS using the suicide plasmid pDM4-based gene knockout systems, and then we use these mutants to study effect of molecular diversit

英文关键词： Vibrio；Type III secretion system；Effector；Diversity；Virulence