BORDETELLA PERTUSSIS TRACHEAL CYTOTOXIN

描述(改编自申请人的摘要)：各种 百日咳杆菌产生的毒素和毒力相关因子， 只有一种已被证明能复制特定的呼吸道 百日咳综合征的肠道细胞病理学。这种分子是 释放的921道尔顿肽聚糖片段--气管细胞毒素(TCT) 在正常生长期间被百日咳杆菌感染。在过去3年中 由美国国立卫生研究院的这笔拨款资助，大多数研究成果 以理解TCT结构-功能关系为中心， 明确TCT靶细胞，阐明TCT的作用机制。 此续订申请侧重于实验，以描述 进一步研究TCT毒性途径、靶细胞特异性和 TCT生产的分子基础。要求在五年内 探索以下具体目标：一、更准确地定义角色 白介素1和一氧化氮在心力衰竭发病机制中的作用 TCT行动。实验将评估IL-1是否真的是一种 TCT毒性途径的关键步骤，并将定义 对TCT有反应的特定呼吸道上皮细胞(和 百日咳杆菌感染)通过合成IL-1和/或NO； 类似的研究将被设计来检查分子基础 对TCT的物种特异性反应性。II.比较TCT的毒性 中性粒细胞对TCT呼吸道已知生物化学和生物学的影响 上皮性效应。TCT对中性粒细胞的有效作用将是 在与我们之前的工作平行的实验中进行了检验 呼吸道上皮细胞：结构-活性关系，证据 对于与表面受体的结合，IL-1和 不，以及与内毒素协同作用的可能性。三、找出 百日咳杆菌释放TCT的遗传学和生物学基础。 这些实验将检验百日咳波尔德氏菌 TCT的释放很大程度上是由于膜有缺陷或缺失 运输蛋白。AMPG，这对肽多聚糖至关重要 回收利用。此外，还将使用一种新的突变筛选来识别 另一个可能参与TCT产生的基因(S)。

DESCRIPTION (Adapted from applicant's abstract): Of the various toxins and virulence-related factors produced by Bordetella pertussis, only one has been demonstrated to reproduce the specific respiratory tract cytopathology of the pertussis syndrome. That molecule is tracheal cytotoxin (TCT),a 921 dalton peptidoglycan fragment released by Bordetella pertussis during normal growth. During the past 3 years of funding by this NIH grant, most of the research effort has centered on understanding TCT structure-function relationships, defining TCT target cells, and elucidating TCT mechanism of action. This renewal application is focused on experiments to describe further the TCT toxicity pathway, target cell specificity, and the molecular basis for TCT production. Five years are requested to explore the following specific aims: I. Define more precisely the role of interleukin-1 (IL-1) and nitric oxide (NO ) in the mechanism of TCT action. Experiments will evaluate whether IL-1 is indeed an essential step in the TCT toxicity pathway and will define the specific respiratory epithelial cells that respond to TCT (and Bordetella pertussis infection) by synthesizing IL-1 and/or NO ; similar studies will be designed to examine the molecular basis for species-specific responsiveness to TCT. II. Compare TCT's toxicity for neutrophils to the known biochemistry and biology of TCT's respiratory epithelial effects. The potent effects of TCT on neutrophils will be examined in experiments that parallel our previous work with respiratory epithelial cells: structure-activity relationships, evidence for binding to a surface receptor, the potential involvement of IL-1 and NO , and the possibility of synergy with endotoxin. III. Identify the genetic and biological basis of TCT release by Bordetella pertussis. These experiments will test the hypothesis that Bordetella pertussis release of TCT is largely due to a defective or missing membrane transport protein. AmpG, that is critical for peptidoglycan recycling. In addition, a novel mutant screen will be used to identify other gene(s) that may be involved in production of TCT.