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Mechanisms and consequences of cytoskeletal control of Helicobacter pylori cell shape

细胞骨架控制幽门螺杆菌细胞形状的机制和后果

基本信息

批准号：
10593366
负责人：
Sophie R. Sichel
金额：
$ 0.65万
依托单位：
FRED HUTCHINSON CANCER CENTER
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10593366
关键词：
Mechanisms consequences cytoskeletal control Helicobacter

项目摘要

PROJECT SUMMARY/ABSTRACT Helicobacter pylori is a helical-shaped Gram-negative pathogen for which the only known niche is the human stomach. H. pylori infects 50% of the world’s population and causes chronic gastritis, which can progress to gastric cancers, or ulcers in a subset of patients [1]. How exactly H. pylori causes severe disease is not fully understood, but in general it occurs through eliciting inflammation. The bacterium’s helical cell shape is essential for multiple facets of early infection; helical strains of H. pylori more robustly colonize mice during acute (one week) infections than non-helical mutants that lack cell shape genes (curved or rod cells) [2-5]. Helical cell shape may promote colonization of the viscous mucous layer of the stomach through a corkscrewing mechanism [6] which allows H. pylori to reach the epithelium and colonize the epithelial surface [7]. Furthermore, additional evidence from mouse models suggests that in chronic infections (one or three months), helical H. pylori elicit higher levels of inflammation and hyperplasia than non-helical mutant strains [5]. How helical cell shape is determined and how it promotes colonization and inflammation of the stomach are two questions essential to our understanding of how H. pylori causes disease. Multiple proteins that are required for helical cell shape in H. pylori have been identified and proposed to form a “shapesome” complex that determines helical cell shape [2- 4, 8]. The hypothesis of this project is that the helical shape of H. pylori contributes to H. pylori’s ability to traverse the mucous layer and interact with the gastric mucosa to induce inflammation and is controlled by the “shapesome” which the cytoskeletal protein CcmA stabilizes and localizes to the inner membrane of H. pylori. The following aims will test this hypothesis: Aim 1 will characterize how each domain of CcmA contributes to polymerization and proper localization of CcmA, Aim 2 will determine whether proper intracellular localization of CcmA is modulated by its interaction partners and whether these interactions are impacted by cell shape-altering point mutations in CcmA, and Aim 3 will investigate whether localization to the epithelium through the mucous layer is impacted by alterations of helical parameters of H. pylori cells. This project will leverage advanced microscopy and organoid culture techniques to inform our understanding of how helical cell shape in H. pylori is determined and how helical cell shape impacts interactions with the gastric epithelium. The research fits the mission of the NIAID by providing knowledge that could advance the development of anti-virulence therapies for H. pylori infection considering clinical isolates of H. pylori increasingly show antibiotic resistance [13-15]. Additionally, this work will enhance understanding of how perturbation of helical cell shape impacts pathogenicity of H. pylori and could be applied to other helical rod-shaped gastrointestinal pathogens.

项目摘要/摘要幽门螺杆菌是一种螺旋形的革兰氏阴性病原体，其唯一已知的生态位是人类胃H.幽门螺杆菌感染了世界上50%的人口，并导致慢性胃炎，可发展为胃癌或溃疡的患者子集[1]。到底H。幽门螺杆菌引起的严重疾病是不完全的这是可以理解的，但一般来说，它是通过引发炎症而发生的。这种细菌的螺旋状细胞形状早期感染的多个方面; H.幽门螺杆菌在急性（1 周）感染比缺乏细胞形状基因的非螺旋突变体（弯曲或杆状细胞）[2 - 5]。螺旋细胞形状可能通过螺旋机制促进胃粘性粘液层的定植[6] 这使得H. pylori到达上皮并在上皮表面定植[7]。此外，额外来自小鼠模型的证据表明，在慢性感染（1或3个月）中，螺旋H.幽门诱发炎症和增生水平高于非螺旋突变株[5]。螺旋细胞的形状确定和它如何促进殖民化和炎症的胃是两个重要的问题，我们对H.幽门螺杆菌引起疾病。螺旋细胞形成所需的多种蛋白质。幽门螺杆菌已经被鉴定并被提出形成决定螺旋细胞形状的"shapesome"复合体[2 - 3]。 4、8]。本课题的假设是H. pylori是H.幽门螺杆菌的穿越能力粘膜层，并与胃粘膜相互作用以诱导炎症，并由细胞骨架蛋白CcmA稳定并定位于H.幽门。以下目标将检验这一假设：目标1将描述CcmA的每个域如何有助于 CcmA的聚合和适当定位，Aim 2将决定CcmA的适当细胞内定位是否 CcmA受其相互作用伴侣的调节，以及这些相互作用是否受到细胞形状改变的影响 CcmA和Aim 3中的点突变将研究是否通过粘膜定位到上皮 H.层螺旋参数的变化对H.幽门螺杆菌细胞该项目将利用先进的显微镜和类器官培养技术，以告知我们的理解如何螺旋细胞形状在H。幽门确定以及螺旋细胞形状如何影响与胃上皮的相互作用。这项研究符合 NIAID的使命是提供可以促进抗病毒疗法开发的知识 H. pylori感染考虑临床分离的H.幽门螺杆菌越来越显示抗生素耐药性[13 - 15]。此外，这项工作将提高螺旋细胞形状的扰动如何影响致病性的理解阁下于pylori感染，并可应用于其他螺旋杆状胃肠道病原体。