Analysis of an orchestrated cell death mediated by Vibrio parahaemolytics T3SS1

副溶血弧菌 T3SS1 介导的精心策划的细胞死亡分析

• 批准号: 7867642
• 负责人: Kim Orth
• 金额: $ 39.63万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-05 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7867642
• 关键词: Autophagocytosis; Bacteria; Biochemical; Biochemical Genetics; Bioinformatics; Cell Death; Cells; Cessation of life; Consumption; Cytolysis; Cytosol; Disease Outbreaks; Enteral; Environment; Event; Future; Gastroenteritis; Genomics; Global Warming; Goals; Gram-Negative Bacteria; Incidence; Infection; Link; Marines; Mediating; Microarray Analysis; Microbial Genetics; Microbiology; Modeling; Molecular; Molecular Target; Needles; Open Reading Frames; Pathogenesis; Pathogenicity Island; Post-Translational Protein Processing; Prevalence; Proteins; Role; Seafood; Signal Pathway; Signal Transduction; Structure; Techniques; Temperature; Type III Secretion System Pathway; Vibrio; Vibrio parahaemolyticus; Viral Oncogene; Virulence Factors; Water; Yersinia; cellular targeting; cytotoxicity; extracellular; gastrointestinal; infancy; insight; novel; pathogen; public health relevance

DESCRIPTION (provided by applicant): The ultimate goal of this application is to identify the host signaling pathways targeted by the type III secretion system 1 (T3SS1) of the gram-negative bacterium Vibrio parahaemolyticus; a major agent responsible for gastroenteritis outbreaks associated with the consumption of contaminated seafood. The prevalence of V. parahaemolyticus in the environment and incidence of infection have been linked to rising water temperatures caused by global warming. A T3SS is a needle-like structure that efficiently translocates virulence factors from bacteria into the cytosol of a host cell. The virulence factors (also called bacterial effectors) have evolved in a manner similar to many of the viral oncogenes; a eukaryotic activity is usurped and modified by the pathogen for its own advantage. Genomic sequencing of V. parahaemolyticus revealed the existence of two pathogenicity islands that encode both a T3SS and putative effectors. The first pathogenicity island contains T3SS1 and is associated with a cytotoxicity, while the second pathogenicity island contains T3SS2 and is associated with an enterotoxicity. The effectors on the first pathogenicity island have been identified as open reading frames with no obvious homology to any known protein. Recently, we have demonstrated that the V. parahaemolyticus uses T3SS1 to orchestrate a multifaceted host cell infection by induction of autophagy, cell rounding and then cell lysis. We have shown one of the T3SS1 effectors, VopS, utilizes a novel posttranslational modification called AMPylation to disrupt host signaling. Herein, we propose Specific Aims to study the multifaceted death induced by T3SS1 by identifying the activity and host targets of three known effectors, identify other effectors secreted by T3SS1 and characterize the host signaling pathways that are disrupted by V. parahaemolyticus during infection. These studies provide molecular insight into the molecular mechanisms used by this harmful gastrointestinal bacterial pathogen V. parahaemolyticus. PUBLIC HEALTH RELEVANCE: The gram-negative bacterium Vibrio parahaemolyticus is a major agent responsible for gastroenteritis outbreaks associated with the consumption of contaminated seafood. The prevalence of V. parahaemolyticus in the environment and incidence of infection have been linked to rising water temperatures caused by global warming. Genomic sequencing of the marine bacterium V. parahaemolyticus revealed the existence of two pathogenicity islands that encode both a type III secretion system (T3SS) and putative effectors. Herein, we propose Specific Aims to study the multifaceted death induced by T3SS1 by identifying the activity and host targets of three known effectors, identify other effectors secreted by T3SS1 and characterize the host signaling pathways that are disrupted by V. parahaemolyticus during infection.

描述（申请人提供）：本申请的最终目标是鉴定革兰氏阴性菌副溶血弧菌的III型分泌系统1（T3SS1）靶向的宿主信号通路；与食用受污染的海鲜有关的胃肠炎爆发的主要致病因素。环境中副溶血性弧菌的流行和感染发生率与全球变暖导致的水温上升有关。 T3SS 是一种针状结构，可有效地将细菌中的毒力因子转移到宿主细胞的细胞质中。毒力因子（也称为细菌效应子）的进化方式与许多病毒癌基因类似。真核生物的活性被病原体为了自身利益而篡夺和改变。副溶血弧菌的基因组测序揭示了存在两个编码 T3SS 和推定效应子的致病岛。第一个致病性岛包含T3SS1并且与细胞毒性相关，而第二个致病性岛包含T3SS2并且与肠毒性相关。第一个致病岛上的效应子已被鉴定为开放阅读框，与任何已知蛋白质没有明显的同源性。最近，我们证明副溶血弧菌利用 T3SS1 通过诱导自噬、细胞变圆和细胞裂解来协调多方面的宿主细胞感染。我们已经证明 T3SS1 效应器之一 VopS 利用一种称为 AMPylation 的新型翻译后修饰来破坏宿主信号传导。在此，我们提出具体目标，通过识别三个已知效应器的活性和宿主靶标来研究 T3SS1 诱导的多方面死亡，识别 T3SS1 分泌的其他效应器并表征感染期间被副溶血弧菌破坏的宿主信号通路。这些研究提供了对这种有害胃肠道细菌病原体副溶血弧菌使用的分子机制的分子见解。 公共卫生相关性：革兰氏阴性细菌副溶血弧菌是导致与食用受污染海鲜相关的胃肠炎爆发的主要病原体。环境中副溶血性弧菌的流行和感染发生率与全球变暖导致的水温上升有关。对海洋细菌副溶血弧菌的基因组测序揭示了存在两个编码 III 型分泌系统 (T3SS) 和推定效应子的致病岛。在此，我们提出具体目标，通过识别三个已知效应器的活性和宿主靶点来研究 T3SS1 诱导的多方面死亡，识别 T3SS1 分泌的其他效应器并表征感染期间被副溶血弧菌破坏的宿主信号通路。