Mycoplasma – Structural Characterization of Host Cell Interaction Determinants

支原体 â 宿主细胞相互作用决定因素的结构表征

• 批准号: 274962763
• 负责人: Professor Dr. Achilleas Frangakis
• 金额: --
• 依托单位: Institut für Biophysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/274962763?language=en
• 关键词: Mycoplasma; Structural; Characterization; Host; Cell

Mycoplasmas are among the smallest and simplest prokaryotes capable of self-replication, with a genome which may be as small as 600 kbases. They are significant pathogens that may induce clinically relevant manifestations. In the previous funding period we used cryo- electron microscopy to solve the structure of the main adhesion complex of Mycoplasma pneumoniae and Mycoplasma genitalium, the Nap, that is responsible for the adhesion of the pathogens to host cells and indispensable for manifesting the infection. In addition, we studied numerous mutants of M. genitalium by cryo-electron tomography, which allowed for explaining the mechanism of adhesion and motility. Here we apply for funding to continue this study using two avenues: (i) Using single-particle cryo-electron microscopy to solve the structure of the intracellular part of the Nap (Napic), for which we have evidence that it is responsible for triggering the adhesion release mechanism, and of further immunodominant and/or abundant Mycoplasma surface proteins (specifically P116/MG075 and MPN474/MG328). The structures will complement our previous structures of the main adhesin and should provide us with a complete mechanistic understanding of the adhesion. Mechanistic understanding of the adhesion has the potential for facilitating development of new therapeutics against these pathogens that are notoriously difficult to control with current antibiotics. (ii) Using cryo- electron tomography and a focused-ion-beam approach, we would like to investigate the direct interaction of the Mycoplasmas with host cells to understand how the infection manifests. In particular, we would also like to visualize the adhesion of Mycoplasmas to epithelial cilia, which apparently causes ciliary dysfunction during the infection. For both of the above avenues we have already done significant prior work, both independently and as members of a vibrant collaborative community. Finally, the motivation for our work is reinforced by recent studies that have reported a critical role of Mycoplasma pneumoniae for the clinical outcome of viral infections of the respiratory tract.

分枝杆菌是能够自我复制的最小，最简单的原核生物之一，其基因组可能小于600 kbase。它们是可能引起临床相关表现的重要病原体。在上一个资金期间，我们使用冷冻电子显微镜解决了支原体肺炎和支原体生殖器的主要粘附复合物的结构，即NAP，这是导致病原体对宿主细胞粘附的粘附，并具有表现出感染的必不可少的。此外，我们通过冷冻电子断层扫描研究了许多生殖器分枝杆菌的突变体，从而解释了粘附和运动的机制。在这里，我们申请资助以使用两个途径继续进行这项研究：（i）使用单粒子冷冻电子显微镜解决NAP（NAPIC）的结构（NAPIC），为此，我们有证据表明它负责触发粘合机制，以及进一步的免疫和/或更多的Mycoplas蛋白（均为/或多余的mycoplas precyp116）（ MPN474/MG328）。这些结构将补充我们先前的主要粘附素结构，并应为我们提供对粘附的完全机械理解。对粘附的机械理解有可能促进针对这些病原体的新疗法的发展，而这些病原体众所周知，这些病原体很难用当前的抗生素来控制。 （ii）使用冷冻电子断层扫描和聚焦的离子梁方法，我们想研究分枝杆菌与宿主细胞的直接相互作用，以了解感染的表现。特别是，我们还想可视化支原体对上皮纤毛的粘附，这显然在感染过程中会引起睫状功能障碍。对于上述这两种途径，我们已经独立和作为充满活力的协作社区的成员进行了重要的先前工作。最后，最近的研究增强了我们工作的动机，这些研究报道了支原体肺炎在呼吸道病毒感染的临床结果中的关键作用。