Type III exported effectors of Chlamydia trachomatis

描述(由申请人提供)：由于沙眼衣原体的流行以及急性和慢性疾病对健康和社会经济的综合影响，沙眼衣原体在美国是一个令人严重关注的问题。衣原体是专有的细胞内病原体，具有从膜结合的液泡内调节宿主细胞功能的能力，称为包涵体。衣原体表达一种与毒力相关的III型分泌系统，可能用于创造和维持允许的生长环境。我们已经鉴定了多种衣原体III型底物，并建议阐明它们抗宿主活性的分子机制，并描述这些相互作用的后果。此外，我们还建议使用遗传和生化方法来扩大已识别的宿主交互作用衣原体产物的数量。为了确定衣原体蛋白与宿主靶标的相互作用，将采用多种方法相结合的方法来确定相关功能。这些已阐明的体外相互作用将在衣原体感染中通过一系列结合质谱学的交联法和共沉淀法得到证实。这些相互作用的后果将在组织培养感染模型中进行调查，以评估衣原体发育对各自功能的需求。衣原体III型分泌系统代表了一种诱人的，但相对未被探索的实现宿主细胞活动调节的机制。鉴于专性细胞内细菌的研究相对困难，研究III型分泌机制所特有的宿主途径是阐明新的致病机制的有效途径。这些研究将导致对衣原体介导的疾病的更好的理解，并有可能产生新的预防和治疗方法。

DESCRIPTION (provided by applicant): The human pathogen Chlamydia trachomatis is a significant concern in the United States due to its prevalence and the combined health and socioeconomic impact of acute and chronic disease. Chlamydiae are obligate intracellular pathogens and possess the ability to modulate host-cell functions from within a membrane-bound vacuole termed an inclusion. Chlamydiae express a virulence-associated type III secretion system presumably employed to create and maintain a permissive growth environment. We have identified multiple chlamydial type III substrates and propose to elucidate the molecular mechanisms of their anti-host activities and delineate the consequences of those interactions. We, furthermore, propose to extend the number of identified host-interactive chlamydial products using genetic and biochemical approaches. A combination of methods designed to identify interactions of chlamydial proteins with host targets will be employed to establish relevant functions. These elucidated in vitro interactions will be confirmed in chlamydial infections using a series of crosslinking and co-precipitation assays in combination with mass spectroscopy. The consequences of these interactions will be investigated in a tissue culture infection model in order to evaluate the requirement of respective functions in chlamydial development. The chlamydial type III secretion system represents an attractive, yet relatively unexplored, mechanism to achieve modulation of host cell activities. Given the comparative difficulty associated with study of obligate intracellular bacteria, investigation of host pathways specifically targeted by the type III secretion mechanism represents a productive approach to elucidate novel pathogenic mechanisms. These studies will lead to an enhanced understanding of Chlamydia-mediated disease and have the potential to yield novel preventative and treatment therapies.