Identification of human host factors involved in Chlamydia development

描述（由申请人提供）：衣原体是革兰氏阴性细菌病原体，可感染广泛的宿主并引起各种疾病，包括发展中国家可预防的失明、性传播疾病和肺炎。衣原体在细胞内复制的膜结合区室，潜在地作为一个保护盾牌对免疫监视，但也作为一个“平台”，以交换因子与宿主细胞。尽管衣原体作为人类病原体的首要重要性，但对感染过程中涉及的细菌和宿主因素知之甚少。知识的缺乏主要是由于衣原体不是一种遗传上易处理的生物体，以及在哺乳动物宿主中进行遗传方法的困难。我们建议进行全基因组siRNA筛选，以确定和表征参与沙眼衣原体感染后侵袭事件的人类宿主因素。我们已经证明了该方法在基因组的一个子集上的可行性，我们建议将该方法扩展到整个人类基因组（Aim#1）。由于RNAi治疗已被证明与与靶基因显示有限序列同源性的基因的意外沉默有关，我们将对候选物进行系统验证程序，以明确建立靶基因敲除与观察到的表型之间的功能关系（Aim#2）。最后，我们将进行二次检测，以确定和表征衣原体特异性候选人参与后入侵事件的C。沙眼衣原体细胞内发育（目标#3）。总的来说，这一发展提案可能为衣原体发病机制提供新的见解，并为未来与衣原体相关的已知和/或新途径的表征相关的资金申请产生所需的初步结果。沙眼感染 公共卫生相关性：衣原体是专性细胞内细菌病原体，导致各种疾病，如沙眼，性传播疾病和肺炎。我们研究衣原体如何劫持细胞成分，成功地复制和传播内的主机。我们专注于解剖的细胞机制（S）invloved在感染过程中，通过识别衣原体发展所需的宿主因子。这些因素的识别可能有助于设计新的治疗方法。

DESCRIPTION (provided by applicant): Chlamydia are Gram-negative bacterial pathogens that infect a wide range of hosts and cause various diseases, including preventable blindness in developing countries, sexually transmitted disease and pneumonia. Chlamydia replicate intracellularly in a membrane-bound compartment that potentially serves as a protector shield against immune surveillance but also acts as a "platform" to exchange factors with the host cell. Despite the primary importance of Chlamydia as a human pathogen, little is known about the bacterial and host factors involved in the infection process. This paucity of knowledge is mainly due to the fact that Chlamydia is not a genetically tractable organism and to the difficulty of conducting genetic approaches in the mammalian host. We propose to conduct a genome-wide siRNA screen in order to identify and characterize human host factors involved in post-invasion events of Chlamydia trachomatis infection. We have demonstrated the feasibility of the approach on a subset of the genome and we propose to extend the approach to the entire human genome (Aim#1). Since RNAi treatment has been shown to be associated with the unintended silencing of genes displaying limited sequence homology with the targeted gene, we will perform a systematic validation procedure of the candidates to unambiguously establish a functional relationship between the knock-down of the targeted gene and the observed phenotype (Aim#2). Finally, we will conduct secondary assays to identify and characterize Chlamydia specific candidates involved in post-invasion events of C. trachomatis intracellular development (Aim#3). Overall, this developmental proposal is likely to provide new insights in Chlamydia pathogenesis and to generate the required preliminary results for future funding application(s) related to the characterization of known and/or novel pathway(s) involved in C. trachomatis infection. PUBLIC HEALTH RELEVANCE: Chlamydia are obligate intracellular bacterial pathogens responsible for various diseases such as trachoma, sexually transmitted disease and pneumoniae. We study how Chlamydia hijack cellular components to successfully replicate and disseminate inside the host. We focus on dissecting the cellular mechanism(s) invloved in the infection process by identifying the host factors required for Chlamydia development. The identification of these factors may help design new therapeutic treatments.