Type III exported effectors of Chlamydia trachomatis

描述（由申请人提供）：由于其流行率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空泡内调节宿主细胞功能的能力。衣原体表达一种与毒性相关的III型分泌系统，可能是用来创造和维持一个宽松的生长环境。我们已经确定了多种衣原体III型底物，并建议阐明其抗宿主活性的分子机制，并描绘这些相互作用的后果。此外，我们建议扩大主机相互作用衣原体产品的数量，使用遗传和生化方法。将采用旨在鉴定衣原体蛋白与宿主靶点相互作用的方法组合来建立相关功能。这些阐明的体外相互作用将在衣原体感染中使用一系列交联和共沉淀试验结合质谱法进行确认。将在组织培养感染模型中研究这些相互作用的后果，以评价衣原体发育中各自功能的需求。衣原体III型分泌系统代表了一种有吸引力的，但相对未开发的，实现宿主细胞活动的调节的机制。考虑到与专性细胞内细菌的研究相关的比较困难，研究III型分泌机制特异性靶向的宿主途径代表了阐明新致病机制的有效方法。这些研究将有助于加深对衣原体介导的疾病的理解，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.