Structure of Chlamydia-Specific Host Cell Vacuoles

描述（由申请人提供）：衣原体是一种专性细胞内细菌病原体，是广泛的人类疾病的原因，包括性传播疾病，致盲沙眼和可能的冠状动脉疾病。感染的唯一宿主细胞标志是含有衣原体的液泡，称为包涵体。衣原体感染哺乳动物细胞，只在包涵体内分化和生长。包涵体是一种独特的细胞隔室，可将衣原体从宿主细胞质中隔离出来。这个隔室被衣原体蛋白和宿主脂质修饰。与宿主的相互作用和所需宿主营养物质的获取必须通过包涵膜进行翻译。这个宿主细胞隔室是衣原体细胞内生物学和寄生的基石，尽管对其组成、结构或功能知之甚少。我们的假设是，包涵体定义了衣原体生物学的要素，这些要素对衣原体的生长和分化以及与其他宿主细胞区室的相互作用至关重要。本申请的具体目的是开发用于内含物纯化的实验方法，以确定其组成和生物功能。这项研究将促进衣原体基础和应用研究的跨学科方法的进步。长期目标是了解衣原体生长和分化的要求，并确定与其他宿主细胞区室相互作用的分子基础和作用。这将为制定新的干预办法提供重要的基础资料。这些研究的意义在于扩大研究能力，促进对衣原体发病机制和毒力作为衣原体与宿主之间积极相互作用的基本机制的理解。具体目的是：1)分离纯化衣原体包涵体。2)表征包合膜组成。3)评价孤立包裹体的功能能力。公共卫生相关性：衣原体生物引起具有重大公共卫生和医学意义的细菌感染。像病毒一样，衣原体必须感染人体细胞才能生长并引起疾病；然而，这个过程还没有被理解。本研究将为衣原体感染的预防和控制提供微生物在细胞中的生存机制。

DESCRIPTION (provided by applicant): Chlamydia is an obligate intracellular bacterial pathogen that is the cause of a wide spectrum of human diseases, including sexually transmitted diseases, blinding trachoma and possibly coronary artery disease. The singular host cell hallmark of infection is the vacuole that contains chlamydiae, called the inclusion. Chlamydiae infect mammalian cells and differentiate and grow only within the inclusion. The inclusion is a unique cellular compartment that physically sequesters chlamydiae from the host cytosol. This compartment is modified by chlamydial proteins and host lipids. Interactions with the host and acquisition of required host nutrients must be translated across the inclusion membrane. This host cell compartment represents the keystone to chlamydial intracellular biology and parasitism, although little is known about its composition, structure or function. Our hypothesis is that the inclusion defines elements of chlamydial biology that are essential for chlamydial growth and differentiation, and interactions with other host cell compartments. The specific aims of this application target the development of experimental methods for the purification of inclusions that enable defining their composition and biological functions. This research will promote advancement of methodologies across disciplines of basic and applied chlamydial research. The long-term objectives are to understand the requirements for chlamydial growth and differentiation, and determine the molecular bases and roles for interaction with other host cell compartments. This will yield important fundamental information for the development of new approaches for intervention. The significance of these studies is to expand the capacity for research and to advance the understanding of fundamental mechanisms of chlamydial pathogenesis and virulence as an active interplay between chlamydiae and their hosts. The specific aims are: 1) Isolate and purify chlamydial inclusions. 2) Characterize inclusion membrane composition. 3) Evaluate functional capacity of isolated inclusions. PUBLIC HEALTH RELEVANCE: Chlamydia organisms cause bacterial infections with major public health and medical significance. Like a virus, Chlamydia must infect human cells to grow and cause disease; yet, this process is not understood. This research will establish the mechanism of microbial survival in cells that will serve as targets for prevention and control of chlamydial infection.