Structure of Chlamydia-Specific Host Cell Vacuoles

描述（由申请方提供）：衣原体是一种专性细胞内细菌病原体，是多种人类疾病的原因，包括性传播疾病、致盲性沙眼和可能的冠状动脉疾病。感染的单一宿主细胞标志是含有衣原体的空泡，称为包涵体。衣原体感染哺乳动物细胞并仅在内含物内分化和生长。包涵体是一个独特的细胞区室，物理隔离宿主细胞质中的衣原体。这个区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的宿主营养物质的获取必须通过包涵体膜进行翻译。这种宿主细胞室代表了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，列入定义的衣原体生物学要素，是必不可少的衣原体生长和分化，并与其他宿主细胞室的相互作用。本申请的具体目标是开发用于纯化内含物的实验方法，从而能够定义其组成和生物学功能。这项研究将促进基础和应用衣原体研究跨学科方法的进步。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本信息。这些研究的意义在于扩大研究能力，并促进对衣原体致病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)表征包涵体膜组成。3)评价孤立夹杂物的功能能力。公共卫生相关性：衣原体微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，这一过程尚不清楚。这项研究将建立微生物在细胞中存活的机制，作为预防和控制衣原体感染的目标。

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.