Mechanistic study of flagellin-induced inflammation

鞭毛蛋白诱导炎症的机制研究

• 批准号: 6560213
• 负责人: TONYIA D EAVES-PYLES
• 金额: $ 16.2万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6560213
• 关键词: Salmonella; bacteria infection mechanism; bacterial cytopathogenic effect; bacterial proteins; chimeric proteins; confocal scanning microscopy; flagellin; gel electrophoresis; gel mobility shift assay; host organism interaction; inflammation; lipopolysaccharides; protein localization; protein quantitation /detection; protein structure function; protein transport; receptor binding; receptor expression; site directed mutagenesis; tissue /cell culture; toll like receptor; transfection /expression vector; vesicle /vacuole

DESCRIPTION (provided by applicant): The goals of this grant are two-fold: The first is to establish funding for the principle investigator to secure a faculty position and develop an independent research program. The second goal is to further characterize the interaction of bacteria and their products with intestinal epithelial host cells. Specifically, experiments are proposed to identify specific regions of pathogenic bacterial flagellin that induce proinflammatory responses and establish how these regions are translocated across polarized epithelial cells to allow recognition of toll- like receptor 5 (TLR5) localized on the basolateral surface. Gram-negative bacterial shock is mediated by the actions of proinflammatory genes induced in response to microbes and their products. Among the surface components of Gram-negative bacteria, a protein that is released by Salmonella, and other pathogenic bacteria, known as flagellin has been shown to potently induce a variety of proinflammatory responses in a number of mammalian cells. Flagellin, the primary structural component of flagella, from Salmonella species and other flagellated bacteria has highly conserved amino and carboxyl termini and a hypervariable central region. The host response to flagellin is being elucidated but additional work is necessary. The conserved regions of flagellin have been shown to induce a vigorous inflammatory response such as lL-8 secretion and nitric oxide production in intestinal epithelial cells via the IkBa/NF-kB pathway. This inflammatory response to flagellin appears to be mediated by TLR5 located on the basolateral surface of intestinal epithelial cells. The data indicates that flagellin plays a crucial role in upregulating inflammation during bacterial infection of the host and is primary microbial factor recognized by the TLR5. The specific aims of this proposal are: 1) to establish the minimal proinflammatory domain(s) within the conserved termini of Salmonella dublin, as well as other pathogenic bacterial flagellin proteins and determine if these same region(s) mediate TLR5 binding, and 2) to determine the mechanism by which live Salmonella mediate the translocation of flagellin across intestinal epithelial cells inducing inflammatory responses in contrast to nonpathogenic intestinal bacterial flora. These studies will provide insights into bacterial and host cells interactions that are critical for establishing disease and will offer new avenues for the development of treatment.

描述(由申请人提供)：这项资助的目标有两个：第一个是为首席研究员提供资金，以确保一个教员职位并发展一个独立的研究项目。第二个目标是进一步表征细菌及其产物与肠道上皮宿主细胞的相互作用。具体地说，我们提议进行实验，以确定致病细菌鞭毛蛋白诱导促炎反应的特定区域，并确定这些区域如何跨极化上皮细胞移位，以允许识别位于基底外侧表面的Toll样受体5(TLR5)。革兰氏阴性细菌休克是由微生物及其产物诱导的促炎基因的作用所介导的。在革兰氏阴性细菌的表面成分中，沙门氏菌和其他病原菌释放的一种蛋白质，即鞭毛蛋白，已被证明能在许多哺乳动物细胞中有效地诱导各种促炎反应。鞭毛蛋白是沙门氏菌和其他鞭毛细菌鞭毛的主要结构成分，具有高度保守的氨基和羧基末端以及一个高度可变的中心区。宿主对鞭毛蛋白的反应正在被阐明，但还需要进一步的工作。鞭毛蛋白的保守区通过IkBA/NF-kB途径在肠上皮细胞中诱导强烈的炎症反应，如IL-8分泌和一氧化氮的产生。这种对鞭毛的炎症反应似乎是由位于肠上皮细胞基底外侧表面的TLR5介导的。这些数据表明，鞭毛蛋白在宿主细菌感染过程中起着上调炎症的关键作用，是TLR5识别的主要微生物因子。这一建议的具体目的是：1)在都柏林沙门氏菌的保守末端建立最小的促炎结构域(S)以及其他致病细菌鞭毛蛋白，并确定这些区域(S)是否介导TLR5结合；2)确定活的沙门氏菌介导鞭毛蛋白跨肠上皮细胞移位诱导炎症反应的机制。这些研究将提供对细菌和宿主细胞相互作用的洞察，这些相互作用对确定疾病至关重要，并将为治疗的发展提供新的途径。