Bacterial Modulation of Epithelial Signaling Pathways

上皮信号通路的细菌调节

• 批准号: 6445815
• 负责人: LAUREN S COLLIER-HYAMS
• 金额: $ 3.83万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6445815
• 关键词: I kappa B beta; Salmonella typhimurium; bacterial proteins; biological signal transduction; epithelium; host organism interaction; immunofluorescence technique; nuclear factor kappa beta; phosphorylation; postdoctoral investigator; protein degradation; transfection; ubiquitin; western blottings

DESCRIPTION (provided by applicant): This proposal aims to characterize the effects of the Salmonella typhimurium type III-secreted AvrA effector protein on NF-kB activation and test the general hypothesis that some Salmonella strains have evolved a mechanism to modulate epithelial proinflammatory signaling pathways. S. typhimurium is a common cause of foodborne enterocolitis in this country and the developing world. The inflammation typically associated with S. typhimurium infections results from recruitment of PMNs by the chemotactic cytokine IL-8. IL-8 and other inflammatory mediators can be activated by NF-kB. While it has been demonstrated that some Salmonella strains activate NF-kB, we have identified several nonpathogenic strains which inhibit NF-kB activation. Based on our preliminary data showing that the AvrA effector blocks TNF-induced NF-kB activation, the goals of the work proposed here are to determine if AvrA is responsible for the anti-inflammatory effects of these nonpathogenic Salmonella strains on activation of NF-kB and to define the inhibitory effect of AvrA on NF-kB activation. In cells transfected with AvrA, nuclear translocation of NF-kB will be assessed by immunofluorescence techniques and effects on IkB-a phosphorylation, ubiquitination, and degradation will be determined by Western blot. In addition, AvrA knockout Salmonella strains will be constructed and the ability of these mutants to inhibit NF-kB activation will be tested.

描述（申请人提供）：该提案旨在表征 鼠伤寒沙门氏菌型III型AVRA效应蛋白的影响 关于NF-KB激活并检验一些沙门氏菌的总体假设 菌株已经发展了一种调节上皮促炎性的机制 信号通路。鼠伤寒链球菌是食源性小肠结肠炎的常见原因 在这个国家和发展中国家。炎症通常相关 鼠伤寒链球菌感染是由PMN招募的 趋化性细胞因子IL-8。 IL-8和其他炎症介质可以是 由NF-KB激活。虽然已经证明了一些沙门氏菌菌株 激活NF-KB，我们已经确定了几种抑制的非致病菌株 NF-KB激活。根据我们的初步数据，表明AVRA效应器 阻止TNF诱导的NF-KB激活，此处提出的工作的目标是 确定AVRA是否负责这些 非致病性沙门氏菌菌株激活NF-KB并定义 AVRA对NF-KB激活的抑制作用。在用Avra转染的细胞中， NF-KB的核易位将通过免疫荧光评估 对IKB-A磷酸化，泛素化和影响的技术和影响 退化将由Western印迹确定。此外，Avra淘汰赛 沙门氏菌菌株将被构造，这些突变体的能力 将测试抑制NF-KB激活。