The molecular mechanisms of bacterial outer membrane vesicle formation

描述(申请人提供)：大量的革兰氏阴性细菌自然产生细胞外膜泡(MVS)。这些小泡来源于外膜，含有外膜和周质蛋白。MVS是细菌毒力的重要组成部分，因为它们是将细菌毒素运送到真核细胞的载体。除了转运毒素外，我们实验室最近还发现，条件致病菌铜绿假单胞菌利用MVS在铜绿假单胞菌细胞之间运输细胞-细胞信号分子PQS。由于PQS信号是致病所必需的，MVS是铜绿假单胞菌致病的关键成分。虽然MVS在发病机制中的作用是明确的，但目前对MV形成的分子机制尚不清楚。本研究的目的是确定铜绿假单胞菌中MV形成的分子机制。为此，建立了MV形成的分子模型，并提出了检验该模型的三个具体目标。这些特异性目标提出了遗传、生化和生理技术来确定PQS(特异性目标1)、脂多糖(特异性目标2)和PG相关OM蛋白(特异性目标3)在MV形成中的作用，最终目的是准确地确定MV的形成机制。由于它们在毒素和信号转运中的作用，了解MVS是如何产生的将为了解铜绿假单胞菌的信号转导和疾病提供新的见解。最终，了解MV形成的分子机制可能会通过开发控制MV产生的技术为抗菌药物的开发提供新的靶点。种群内的细菌交流对许多细菌的致病性至关重要，包括铜绿假单胞菌。这个项目的目标是提供对铜绿假单胞菌如何沟通的基本了解，最终目标是设计出扰乱这种沟通的方法。

DESCRIPTION (provided by applicant): A large number of Gram-negative bacteria naturally produce extracellular membrane vesicles (MVs). These vesicles are derived from the outer membrane (OM) and contain OM and periplasmic proteins. MVs are an important component of bacterial virulence as they serve as trafficking vehicles for bacterial toxins to eukaryotic cells. In addition to trafficking toxins, our laboratory recently discovered that the opportunistic pathogen Pseudomonas aeruginosa utilizes MVs to traffic the cell-cell signaling molecule PQS between P. aeruginosa cells. Since PQS signaling is required for virulence, MVs are a critical component of P. aeruginosa pathogenicity. Although the roles of MVs in pathogenesis are clear, the molecular mechanism of MV formation is not currently understood. The goal of this proposal is to determine the molecular mechanism of MV formation in P. aeruginosa. To this end, a molecular model for MV formation has been developed, and three specific aims are proposed to test this model. These specific aims propose genetic, biochemical, and physiological techniques to exact a role for PQS (specific aim 1), lipopolysaccharide (specific aim 2), and pg-associated OM proteins (specific aim 3) in MV formation, with the ultimate goal of precisely defining the mechanism of MV formation. Due to their role in toxin and signal trafficking, understanding how MVs are produced will provide new insight into P. aeruginosa signaling and disease. Ultimately, understanding the molecular mechanism of MV formation may provide a novel target for antimicrobial development through development of technology to control MV production. Bacterial communication within a population is critical for pathogenicity of many bacteria, including the bacterium Pseudomonas aeruginosa. The goal of this project is to provide a fundamental understanding of how P. aeruginosa communicates, with the ultimate goal of devising ways to disrupt this communication.