How chlamydia generates cytoskeletal scaffolds and their role during infection

项目总结 细胞内沙眼衣原体是性传播疾病的主要原因， 传染性失明，全世界有超过1.5亿例。一旦进入细胞，衣原体就会在 被包裹在肌动蛋白和微管支架中的寄生室称为包涵体。肌动蛋白支架 提供包裹体的完整性，而微管(MT)控制包涵体周围高尔基体的重新定位；两者 这些事件对于衣原体的生存是必要的。尽管细胞骨架重排对 衣原体的生命周期，关于这种细菌用来控制 细胞骨架。此外，衣原体在感染期间将多个宿主细胞器重定向到它的包涵体。 值得注意的是，控制这种重新定位的是哪种细胞骨架支架，仍有待确定。值得注意的是，这是一个 关键问题是细胞器的重新定位增强了脂类和营养物质向包涵体的转移，从而 有助于包涵膜的生长和细菌的复制。 利用最近建立的转基因衣原体菌株，我们建议研究新的 衣原体蛋白(也称为效应物)在细胞骨架支架的形成中起作用。这些效应器已经被 被证明与转基因细胞中的细胞骨架蛋白相互作用，因此是理想的候选者 在感染过程中操纵细胞骨架。具体地说，我们将检验这样的假设：1)衣原体建立了一种 多种细菌和宿主蛋白组成的分子平台协调肌动蛋白和MT 感染期间的重排，以及2)当细胞骨架围绕包涵体编织时， 然后，各种细胞器转向包涵体，以促进衣原体的生存。 最终，这些信息将产生广泛的科学影响，因为(I)它将建立详细的机制 衣原体用来改变两个主要细胞骨架成分的用途，以实现自身的利益，并将提供更好的 了解疾病进展；(Ii)细胞骨架重排在癌症中起关键作用 发展。由于衣原体感染与癌症风险的增加有关，因此理解 细胞骨架在感染期间如何重组将有助于揭示这一现象；(Iii)理解 控制细胞骨架动力学的机制将提供对基础生物学的重要洞察 途径，以及(Iv)最后，控制细胞骨架动力学的蛋白质的详细特征 衣原体感染将为筛查其他主要疾病中是否存在类似效应物提供基本工具 也操纵宿主细胞骨架的人类病原体，特别是沙门氏菌，从而开辟了新的途径 在分子发病机制方面的研究。

PROJECT SUMMARY The intracellular bacterium Chlamydia trachomatis is a major cause of sexually transmitted disease and infectious blindness with over 150 million cases worldwide. Once inside the cell, Chlamydia replicates in a parasitic compartment called an inclusion, which is encased in actin and microtubules scaffolds. Actin scaffolds provide inclusion integrity, while microtubules (MT) control Golgi repositioning around the inclusion; both of these events are necessary for Chlamydia survival. Despite the importance of cytoskeleton rearrangements for Chlamydia's life cycle, a major gap exists regarding the molecular mechanism used by this bacterium to control the cytoskeleton. Furthermore, Chlamydia redirects multiple host organelles to its inclusion during infection. Remarkably, which cytoskeleton scaffold controls this repositioning remains to be identified. Of note, this is a key question as organelle repositioning enhances lipid and nutrient transfer to the inclusion, which then contribute to the growth of the inclusion membrane and the replication of the bacteria. Using recently established genetically-modified Chlamydia strains, we propose to study the role of novel chlamydial proteins (also called effectors) in the formation of cytoskeleton scaffolds. These effectors have been shown to interact with cytoskeleton proteins in transfected cells and are, therefore, ideal candidates to manipulate cytoskeleton during infection. Specifically, we will test the hypotheses that 1) Chlamydia builds a molecular platform composed of multiple bacterial and host proteins to coordinate actin and MT rearrangements during infection, and 2) as cytoskeletal scaffolds are woven around the inclusion, various organelles are then diverted towards the inclusion to promote Chlamydia's survival. Ultimately, this information will have a broad scientific impact as (i) It will establish the detailed mechanism used by Chlamydia to repurpose two major cytoskeleton elements for its own benefit and will provide a better understanding of disease progression; (ii) Cytoskeleton rearrangement plays a critical role in cancer development. Since Chlamydia infection has been associated with an increased risk of cancer, understanding how the cytoskeleton is reorganized during infection will shed light on this phenomenon; (iii) Understanding the mechanism that controls cytoskeleton dynamics will provide critical insight into fundamental biological pathways, and (iv) Finally, a detailed characterization of the proteins that control cytoskeletal dynamics during Chlamydia infection will provide fundamental tools to screen for the presence of similar effectors in other major human pathogens that also manipulate host cytoskeleton, in particular Salmonella, thus opening new avenues of research in molecular pathogenesis.