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，人类病原体沙眼衣原体在美国是一个重要的问题。衣原体是专性细胞内病原体，具有从称为包涵体的膜结合液泡内调节宿主细胞功能的能力。衣原体表达一种毒力相关的III型分泌系统，可能用于创造和维持一个宽松的生长环境。我们已经确定了多种III型衣原体底物，并建议阐明其抗宿主活性的分子机制，并描述这些相互作用的后果。此外，我们建议使用遗传和生化方法来扩大已确定的宿主相互作用衣原体产物的数量。设计用于鉴定衣原体蛋白与宿主靶标相互作用的方法组合将用于建立相关功能。这些阐明的体外相互作用将在衣原体感染中得到证实，使用一系列交联和共沉淀试验结合质谱。这些相互作用的结果将在组织培养感染模型中进行研究，以评估衣原体发育中各自功能的要求。衣原体III型分泌系统代表了一个有吸引力的，但相对未被探索的机制，以实现宿主细胞活性的调节。鉴于专性细胞内细菌的研究相对困难，研究III型分泌机制特异性靶向的宿主途径是阐明新的致病机制的有效途径。这些研究将增进对衣原体介导的疾病的了解，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.