CHLAMYDIAL INVASION OF NON-PHAGOCYTIC CELLS

描述（由申请方提供）：沙眼衣原体是一种革兰氏阴性专性细胞内病原体，是包括沙眼和性传播疾病衣原体在内的多种人类疾病的病原体。衣原体对细胞的成功感染包括附着、侵入、形成保护性空泡（称为包涵体）和抑制溶酶体融合。随着C.随着沙眼衣原体基因组序列和新的细胞生物学和蛋白质组学工具的出现，这些过程中所涉及的机制才刚刚开始被揭示，从而推进了我们对衣原体-宿主细胞相互作用的认识。长期目标是确定衣原体成功建立感染的重要分子和生化机制。这项建议将具体涉及入侵的过程。据推测，衣原体使用多种途径入侵非吞噬细胞。最近鉴定的称为Tarp的分子已被证明从感染的基本体跨宿主质膜易位到胞质溶胶中，在胞质溶胶中其被未知宿主激酶酪氨酸磷酸化，并募集肌动蛋白。作为一种磷蛋白，Tarp可以作为一个信号平台，招募一些衔接子和效应分子，介导肌动蛋白细胞骨架重塑。具体目标1将解决的Rac GT3依赖性途径，并专注于潜在的下游介质的肌动蛋白招聘。具体目标2将集中在Tarp蛋白，酪氨酸激酶（S）负责其磷酸化，结合伙伴，他们在衣原体入侵的作用，和潜在的关系Tarp与Rac GT3。具体目标3将解决肌动蛋白募集的潜在机制，由嗜衣原体Tarp同源物，它不包含多个重复序列存在于C。沙眼衣原体血清型L2和D.这些研究不仅揭示了衣原体生物学的重要见解，而且还揭示了衣原体破坏肌动蛋白细胞骨架以促进其感染的细胞过程。

DESCRIPTION (provided by applicant): Chlamydia trachomatis is a Gram-negative obligate intracellular pathogen that is the causative agent of a wide spectrum of human diseases including trachoma and the sexually transmitted disease chlamydia. Successful infection of cells by chlamydia involves attachment, invasion, establishment of a protective vacuole called an inclusion, and inhibition of lysosomal fusion. With the advent of the C. trachomatis genome sequence and new cell biological and proteomic tools, the mechanisms involved in these processes are just beginning to be revealed, advancing our knowledge of chlamydia-host cell interactions. The long term goal is to define the molecular and biochemical mechanisms important for the successful establishment of infection by chlamydia. This proposal will specifically address the process of invasion. It is hypothesized that chlamydia uses multiple pathways of invading non-phagocytic cells. A recently identified molecule termed Tarp has been demonstrated to be translocated from the infecting elementary body across the host plasma membrane and into the cytosol where it is tyrosine phosphorylated by unknown host kinases, and recruit actin. As a phosphoprotein, Tarp may act as a signaling platform to recruit a number of adapter and effector molecules that mediate actin cytoskeletal remodeling. Specific Aim 1 will address the Rac GTPase dependent pathway and focus on the potential downstream mediators of actin recruitment. Specific Aim 2 will focus on the Tarp protein, the tyrosine kinase(s) responsible for its phosphorylation, the binding partners, their roles in chlamydial invasion, and the potential relationship of Tarp with the Rac GTPase. Specific Aim 3 will address the potential mechanism of actin recruitment by the Chlamydophila caviae Tarp homolog, which does not contain the multiple repeat sequences present in C. trachomatis serovars L2 and D. These studies would not only reveal important insights into the biology of chlamydia, but also the cellular process of signaling to the actin cytoskeleton that chlamydia subverts to facilitate its infection.