Structure of Chlamydia-Specific Host Cell Vacuoles

描述(申请人提供)：衣原体是一种专性的细胞内细菌病原体，是一系列人类疾病的原因，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特征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，只在包涵体内分化和生长。包涵体是一种独特的细胞隔间，它物理上将衣原体从宿主胞浆中隔离出来。这个隔室由衣原体蛋白和宿主脂类修饰。与宿主的相互作用和所需宿主营养的获取必须跨包涵体膜进行翻译。这个寄主细胞室是衣原体细胞内生物学和寄生的基石，尽管人们对其组成、结构或功能知之甚少。我们的假设是，这种包涵体定义了衣原体生物学中对衣原体生长和分化以及与其他宿主细胞隔间相互作用必不可少的元素。这项应用的具体目标是开发纯化包裹体的实验方法，以便能够确定其组成和生物功能。这项研究将促进衣原体基础研究和应用研究各学科方法学的进步。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隔间相互作用的分子基础和作用。这将为制定新的干预方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，促进对衣原体致病和毒力作为衣原体与宿主之间主动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)包涵膜成分的表征。3)评估孤立包裹体的功能容量。公共卫生相关性：衣原体生物体引起细菌感染，具有重大的公共卫生和医学意义。就像病毒一样，衣原体必须感染人类细胞才能生长并导致疾病；然而，这一过程尚不清楚。这项研究将建立微生物在细胞中的生存机制，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.