Role of Yersinia pestis Ail in Yop delivery and plague

鼠疫耶尔森菌 Ail 在 Yop 传播和鼠疫中的作用

基本信息

批准号：
8231326
负责人：
ERIC S KRUKONIS
金额：
$ 19.44万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-03-01 至 2013-05-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Efficient Type Three Secretion (T3S) by Gram-negative bacteria requires adhesion to the targeted host cell. We have recently determined that the Yersinia pestis adhesin Ail facilitates T3S of Yersinia outer proteins (Yops) via binding to host fibronectin. Yop delivery is required for plague infection and mutants that lack Yops are completely avirulent. A ?ail mutant has poor Yop delivery in vitro and is attenuated in vivo (>3000-fold increase in LD50). Thus, Ail appears to be a prominent adhesin for Yop delivery in vivo. This makes Ail an important potential target for Y. pestis vaccine development and anti-plague therapies. We hypothesize that Ail in conjunction with fibronectin interacts with host cells to allow efficient Yop delivery, possibly by stimulating receptor-initiated cell signaling required for Yop delivery. We further hypothesize that Fn acts as a bridge between Ail-expressing bacteria and 21 integrins on host cells (receptors for Fn). ?1 integrin signaling has recently been shown to be important for invasin-mediated Yop delivery by the closely related pathogen, Y. pseudotuberculosis. In this proposal, we will define the regions of Ail that interact with Fn and address the effects of Ail binding to Fn and subsequent engagement of ?1 integrins. By understanding this critical step in the Yop delivery process by a key adhesin of Y. pestis, we will significantly expand our knowledge of the role of adhesion in Yop delivery in particular and T3S in general. These studies will be broadly applicable to other bacterial pathogens that utilize a T3S mechanism for toxin delivery. Furthermore by defining a crucial interaction mechanism between Y. pestis and host cells, we may identify targets for therapeutics that can be used to treat plague, a rapidly fatal disease and bioterrorism threat. The Aims of this proposal are: Aim 1: Determine the residues of Ail required for host cell binding and Yop delivery Aim 2: Characterize Ail binding to host cell fibronectin and the role of 21 integrins in Ail-mediated Yop delivery PUBLIC HEALTH RELEVANCE: Yersinia pestis causes the rapidly fatal infectious disease plague, making Y. pestis a bioterrorism threat. This project is aimed at furthering our understanding of the interaction of the Y. pestis surface protein Ail with host cells. This critical interaction is required for plague virulence and characterizing this interaction may lead to development of anti-plague therapeutics and/or an effective plague vaccine.

描述（由申请人提供）：革兰氏阴性细菌有效的三型分泌（T3S）需要对靶向宿主细胞的粘附。我们最近确定，耶尔森氏菌粘附素可以通过与宿主纤连蛋白结合来促进Yersinia外蛋白（YOPS）的T3s。鼠疫感染和缺乏yops的突变体是完全无动于衷的。 A？ail突变体的体外YOP递送不良，并且在体内会减弱（LD50增加了3000倍）。因此，AIL似乎是体内YOP递送的突出粘合剂。这使AIL成为PESTIS疫苗发育和抗斑块疗法的重要潜在靶标。我们假设与纤连蛋白结合使用与宿主细胞相互作用，以允许YOP递送，这可能是通过刺激YOP递送所需的受体引起的细胞信号传导。我们进一步假设FN充当表达疾病的细菌与宿主细胞上21个整联蛋白之间的桥梁（FN的受体）。最近已经证明，整联蛋白信号传导对于密切相关的病原体Y. pseudotuberculosis对侵入蛋白介导的YOP递送至关重要。在此提案中，我们将定义与FN相互作用的AIL的区域，并解决AIL与FN结合的影响以及随后的1个整合素的参与。通过通过Y. Pestis的关键粘附素理解YOP传递过程中的这一关键步骤，我们将大大扩展我们对粘附在Yop递送中的作用的了解，尤其是T3s。这些研究将广泛适用于使用T3S机制用于毒素递送的其他细菌病原体。此外，通过定义Y. Pestis和宿主细胞之间的至关重要的相互作用机制，我们可以确定可用于治疗瘟疫的治疗剂，迅速致命的疾病和生物恐怖主义威胁。该提案的目的是： AIM 1：确定宿主细胞结合和YOP递送所需的AIL残基 AIM 2：表征与宿主细胞纤连蛋白的AIL结合以及21个整合素在AIL介导的Yop递送中的作用公共卫生相关性：耶尔森宫柴油引起迅速致命的传染病鼠疫，使耶稣成为生物恐怖主义的威胁。该项目的目的是进一步了解我们对Y. Pestis表面蛋白质与宿主细胞相互作用的理解。这种关键的相互作用是鼠疫毒力和表征这种相互作用所必需的，可能会导致抗斑块疗法和/或有效的瘟疫疫苗的发展。