Biogenesis and Function of Bacterial Outer Membrane Vesicles

描述(申请人提供)：这个项目的长期目标是了解革兰氏阴性细菌产生的外膜囊泡的基本方面：它们是如何产生的，为什么产生？在生长的培养中，外膜小泡占总外膜蛋白的0.1%至1%，由迄今研究的所有非致病细菌和致病细菌产生，其中毒力细菌通常产生有毒小泡，比非致病细菌多。然而，关于它们是如何以及为什么制造的基本过程尚不清楚。此前，我们已经发现外膜小泡对革兰氏阴性细菌的基本应激反应有贡献。我们认为，外膜囊泡的产生是由特定的包膜成分控制的，并使周质和外膜内容物能够重塑以响应环境变化和胁迫。细胞被膜蛋白和脂质的快速替换以及囊泡介导的有毒成分的释放可能是细菌在环境中生存的关键因素，特别是为了适应压力。利用新发现的囊泡突变体和本实验室开发的生化技术，本研究旨在阐明囊泡促进细菌适应的机制。本研究的研究目标如下：1)研究细菌囊泡被膜对应激的响应，2)识别和表征囊泡形成途径中的基因，以及3)小泡在细胞被膜重构中的作用。这些结果将对囊泡形成所需的细菌过程产生期待已久的洞察，并将揭示关于这一新描述的应激反应的细节。通过将我们在细菌研究中的发现与相关的真核细胞外体进行比较，将揭示应激产物管理的一般生物学原理。对人类健康的影响是一种常见细菌过程的特征，这种过程可以有针对性地治疗，以增加细菌对抗生素治疗的敏感性。 与公共健康相关：这个项目通过详细介绍我们对细菌囊泡的理解，使公众健康受益。细菌囊泡是一种常见的分泌过程，太多的致病菌使细菌能够抵抗抗生素，并将有毒因素分散到受感染的组织中。这项拟议的研究侧重于揭示囊泡形成的分子基础，旨在促进这一潜在治疗靶点的开发。

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the fundamental aspects of outer membrane vesicles produced by Gram-negative bacteria: How and why are they made? Outer membrane vesicles represent 0.1 to 1% of total outer membrane protein in a growing culture and are produced by all non-pathogenic and pathogenic bacteria studied to date, with virulent bacteria typically producing toxic vesicles and more than non-pathogenic counterparts. Yet the basic processes regarding how and why they are made are unknown. Previously, we have found that outer membrane vesicles contribute a basic stress response of Gram-negative bacteria. We propose that outer membrane vesicle production is governed by specific envelope components and enables remodeling of the periplasmic and outer membrane content in response to environmental changes and stresses. Rapid replacement of cell envelope protein and lipid and vesicle-mediated release of toxic components could be key elements of bacterial survival in the environment, particularly to accommodate stress. Using newly identified vesiculation mutants and biochemistry techniques developed in this laboratory, this research aims to elucidate the mechanism by which vesicles contribute to bacterial adaptation. The research objectives of this study are the following: 1) Characterize the bacterial vesiculation envelope response to stress, 2) Identify and characterize genes in the vesiculation pathway, and 3) Characterize the role of vesicles in cell envelope remodeling. The results will yield long-awaited insight regarding the bacterial processes required for vesicle formation and will reveal details regarding this newly describe stress response. General biological principles of stress product management will be revealed by comparing our findings in the study of bacteria to the related eukaryotic exosomes. The impact on human health is the characterization of a common bacterial process that can be targeted therapeutically to increase bacterial sensitivity to antibiotic treatment. PUBLIC HEALTH RELEVANCE: This project benefits public health by detailing our understanding of bacterial vesiculation, a secretory process common too many pathogenic bacteria that enables bacteria to resist antibiotics and to disperse toxic factors into infected tissues. The proposed research focuses on exposing the molecular basis for vesiculation and aims to facilitate development of this potential therapeutic target.