INTERACTION BETWEEN X NEMATOPHILUS AND ITS HOSTS

X 嗜线虫与其宿主之间的相互作用

• 批准号: 6636334
• 负责人: HEIDI GOODRICH-BLAIR
• 金额: $ 30.19万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2004-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6636334
• 关键词: Nematoda; bacteria; bacteria characteristic; bacteria infection mechanism; bacterial cytopathogenic effect; eukaryote; gene expression; genetic regulation; host organism interaction; microorganism growth; molecular cloning

DESCRIPTION (Adapted from the Applicant's Abstract): This proposal is aimed at understanding how bacteria interact with their eukaryotic hosts and how the availability of nutrients affects these interactions. The bacterium Xenorhabdus nematophilus provides a valuable model system of host microbe interactions: it is a symbiont that resides in the intestine of the nematode Steinernema carpocapsae and a pathogen that kills larval stage insects. The goals of this research are to identify the molecular mechanisms used by X. nematophilus to mediate host interactions. Nutrient deprivation in many Gram-negative bacteria triggers development of increased resistance to stress and the production of virulence determinants. This response is partially regulated by a specific sigma factor, ss. The first specific aim of this proposal is to analyze the role of ss and ss-dependent gene expression in the symbiosis and pathogenicity of X. nematophilus with its eukaryotic hosts. The results of this work will begin to address the genetic regulation of survival and adaptation in X. nematophilus and will provide insight into how the availability of nutrients affects host-bacterium interactions. X. nematophilus is likely to have evolved multiple regulatory mechanisms, including the starvation response, that mediate host interactions. While specific Aim 1 focuses entirely on the starvation response, the goal of Specific Aim 2 is to perform genetic tests to identify additional bacterial regulatory mechanisms that mediate symbiosis between X. nematophilus and the nematode. The goal is to obtain and characterize X. nematophilus mutants that are no longer retained within the intestinal vesicles of nematodes. This work will provide insight into the genes and gene products that are essential for symbiosis and will aid in the elucidation of the regulation of host interactions in X. nematophilus and other bacteria.

描述（改编自申请人的摘要）：该提案旨在了解细菌如何与其真核宿主相互作用以及营养物质的可用性如何影响这些相互作用。嗜线虫致病杆菌为宿主微生物相互作用提供了一个有价值的模型系统：它是一种存在于线虫斯氏线虫肠道中的共生体，也是一种杀死幼虫阶段昆虫的病原体。本研究的目标是确定嗜线虫 X. nematophilus 介导宿主相互作用的分子机制。许多革兰氏阴性细菌的营养缺乏会引发对应激的抵抗力增强和毒力决定因素的产生。该反应部分受特定西格玛因子 ss 调节。该提案的第一个具体目的是分析 ss 和 ss 依赖性基因表达在嗜线虫 X. nematophilus 与其真核宿主的共生和致病性中的作用。这项工作的结果将开始解决嗜线杆菌生存和适应的遗传调控问题，并将深入了解营养物质的可用性如何影响宿主与细菌的相互作用。嗜线虫 X. nematophilus 可能已经进化出多种调节机制，包括介导宿主相互作用的饥饿反应。虽然具体目标 1 完全关注饥饿反应，但具体目标 2 的目标是进行基因测试，以确定介导嗜线虫 X. nematophilus 和线虫之间共生的其他细菌调节机制。目标是获得并表征不再保留在线虫肠小泡内的嗜线虫 X. nematophilus 突变体。这项工作将深入了解共生所必需的基因和基因产物，并将有助于阐明嗜线虫和其他细菌中宿主相互作用的调节。