ENTEROTOXIN FACTORS ELABORATED BY SHIGELLA FLEXNERI

由福氏志贺氏菌阐述的肠毒素因子

• 批准号: 2457786
• 负责人: Alessio Fasano
• 金额: $ 11.85万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2457786
• 关键词: Escherichia coli; Shigella; bacterial genetics; brush border membrane; clinical research; diarrhea; enterotoxins; enzyme linked immunosorbent assay; gastrointestinal absorption /transport; gene expression; gene mutation; genetic promoter element; genetic regulation; genetic transcription; genetic translation; human subject; jejunum; laboratory mouse; laboratory rabbit; monoclonal antibody; perfusion; protein purification; receptor; receptor binding; virulence

DESCRIPTION (Adapted from applicant's abstract): The long term objective of the proposed project is to characterize new enterotoxic determinants potentially involved in the pathogenesis of Shigella flexneri diarrhea. The attenuated S. flexneri vaccine candidates tested so far have shown various degrees of reactogenicity, particularly watery diarrhea. Studies of the PI have resulted in the discovery of enterotoxins elaborated by S. flexneri that have not previously been described. These toxins may be responsible for the residual diarrhea observed during Shigella vaccine trials. The PI proposes to investigate these findings further in a blend of basic and applied studies which will yield fundamental insights into the pathogenesis of S. flexneri diarrhea. These findings will also provide crucial information that can be applied to engineer improved attenuated vaccines. Specific aims are: AIM 1: To purify a new enterotoxic factor of S. flexneri 2a which induces secretion both in vivo and in vitro in animal models. The PI has already partially purified this toxin, termed ShET1 for Shigella enterotoxin 1, and now intends to purify this moiety further and to raise specific monoclonal antibodies to it. AIM 2. To study the genetic regulation of ShET1 and to construct mutants of the set1 genes. The PI has identified, cloned, and sequenced the chromosomal region encoding this factor. He will now characterize these genes and their mechanisms of regulation. AIM 3.To establish the role of ShET1 in the pathogenesis of shigellosis and to study its mechanism of action. The PI will perform intestinal perfusion studies in human volunteers and, using an animal model, will determine ShET1 interaction with enterocyte receptors, its effects on transepithelial water and electrolyte transport, and the intracellular mediator(s) of its enterotoxic effect. AIM 4. To determine whether ShET1 and enteroinvasive Escherichia coli enterotoxin (EIET/ShET2), a second enterotoxin recently described by this group, share any functional similarities.

描述(改编自申请人的摘要)：长期目标 拟议的项目是确定新的肠道毒性决定因素的特征。 可能参与福氏志贺氏菌腹泻的发病机制。这个 到目前为止，测试过的减毒志贺氏菌候选疫苗显示出各种不同的 反应性程度，尤其是水样腹泻。关于PI的研究 导致了由福氏链球菌详细阐述的肠毒素的发现 以前没有被描述过的。这些毒素可能是 在志贺氏菌疫苗试验期间观察到的残留腹泻。《少年派》 建议对这些发现进行进一步的调查，将基础研究和 将对发病机制产生基本见解的应用研究 福氏志贺氏菌腹泻。这些发现也将提供至关重要的 可用于设计改进的减毒疫苗的信息。 具体目标为：目标1：分离纯化一种新的肠毒素。 在动物体内和体外诱导分泌的福氏2a 模特们。PI已经部分提纯了这种毒素，命名为ShET1 志贺氏菌肠毒素1，现在打算进一步纯化这一部分，并 产生特异性的抗它的单抗。 目的2.研究ShET1的遗传调控，构建ShET1的突变体 Set1基因。PI已经识别、克隆并对 编码该因子的染色体区域。他现在将描述这些 基因及其调控机制。 目的：探讨ShET1在志贺氏菌病发病机制中的作用。 研究其作用机制。PI将进行肠道灌流 在人类志愿者身上进行的研究，并将使用动物模型来确定ShET1 与肠细胞受体的相互作用及其对跨上皮水的影响 和电解质转运，以及其细胞内介质(S) 肠道毒性作用。 目的4.检测ShET1和肠侵袭性大肠杆菌 肠毒素(EIET/ShET2)，最近描述的第二种肠毒素 在功能上有什么相似之处。