SALMONELLA TYPHIMURIUM VIRULENCE PLASMID

鼠伤寒沙门氏菌毒力质粒

• 批准号: 2064453
• 负责人: PAUL A GULIG
• 金额: $ 20.24万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 1999-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2064453
• 关键词: Salmonella infections; Salmonella typhimurium; bacterial cytopathogenic effect; bacterial genetics; bacterial proteins; disease /disorder model; gene deletion mutation; host organism interaction; immunocytochemistry; immunopharmacology; laboratory mouse; model design /development; molecular cloning; molecular pathology; pharmacogenetics; phenotype; plasmids; tissue /cell culture; virulence

DESCRIPTION (Adapted from applicant's abstract): Individuals with AIDS and other compromised states experience increased systemic disease caused by Salmonella spp. other than S. typhi. The non-typhoid serovars of salmonellae that cause systemic disease (S. typhimurium, S. dublin, S. enteritidis) possess related virulence plasmids. Results from the previous funding period showed that the five spv genes of the S. typhimurium virulence plasmid cause systemic disease in a mouse model by increasing the growth rate of salmonellae within host cells. However, the molecular and cellular mechanisms of Spv-mediated virulence of salmonellae remain unsolved, and no existing in vitro model reproduces Spv-mediated increased growth rate. The long term goals of the continuation of this project are to elucidate the Spv virulence function and to determine the mechanisms by which the host suppresses growth of intracellular bacteria. The specific aims are to: 1. Identify the mouse cell(s) and their functions which affect virulence plasmid-mediated intracellular proliferation. They will identify the primary host cells in which the Spv function is manifested and secondary cells which suppress Spv-mediated growth by using immunochemical staining of infected mouse tissues; genetic, immunologic, and pharmacologic alteration of mice during infection with Spv+ and Spv-salmonellae. 2. Identify non-spv salmonella genes and their functions that are involved with the Spv phenotype. They will identify proteins differentially expressed by Spv+ and Spv- salmonellae, and Spv-regulated genes will be isolated using gene fusions. They will isolate salmonella mutants defective for intracellular replication in mice. They will combine these mutations with Spv- salmonellae and look for additive effects on virulence. 3. Develop an in vitro model for Spv-mediated intracellular proliferation and utilize the model to elucidate the spv virulence function at the cellular and molecular levels. They will infect animal cell cultures based on the results of aim 1. Once Spv-dependent intracellular growth is reproduced in vitro, we will examine the ultrastructural location of physiological environment of the intracellular bacteria, as well as the host cell response to intracellular infection. They will attempt to reproduce Spv-mediated growth in a cell-free medium and ultimately elucidate the bacterial physiology of virulence plasmid-mediated growth. These studies will elucidate the pathogenic mechanism of the spv genes, identify associated chromosomal virulence genes, and identify host defenses against intracellular bacterial growth. The dissection of the roles of the host and pathogen in intracellular growth will lead to new information about the mechanism of systemic disease caused by salmonellae, as well as other intracellular bacterial pathogens.

描述（改编自申请人的摘要）：艾滋病患者和 其他受影响的国家经历由以下原因引起的系统性疾病增加： 沙门氏菌 除了S。伤寒。 非伤寒血清型 引起全身性疾病的沙门氏菌（S. 鼠伤寒沙门氏菌（S.都柏林，S. 具有相关的毒力质粒。 从以前的结果 研究结果表明，S.鼠伤寒 在小鼠模型中，毒力质粒通过增加 沙门氏菌在宿主细胞内的生长速率。 然而，分子和 沙门氏菌残余物Spv介导毒性的细胞机制 未解决的，并且没有现有的体外模型再现Spv介导的增加 增速 该项目的长期目标是 阐明Spv的毒力功能，并确定其机制， 宿主抑制细胞内细菌的生长。 具体 目标是： 1. 识别小鼠细胞及其功能， 毒力质粒介导的细胞内增殖。 他们将确定 表现出Spv功能的主要宿主细胞和次要宿主细胞 通过使用免疫化学染色， 感染的小鼠组织;遗传学、免疫学和药理学改变 在用Spv+和Spv-沙门氏菌感染期间的小鼠。 2. 确定非spv salvinase基因及其功能， 与Spv表型有关。 他们会鉴别出不同的蛋白质 由Spv+和Spv-鲑精蛋白表达，并且Spv调节的基因将被 使用基因融合分离。 他们会分离出有缺陷的突变体 用于小鼠的细胞内复制。 它们会将这些变异联合收割机 与Spv-沙门氏菌，并寻找毒力的累加效应。 3. 建立Spv介导的细胞内 利用该模型阐明spv的毒力功能 在细胞和分子水平上。 它们会感染动物细胞培养物 根据目标1的结果。 一旦Spv依赖的细胞内生长 在体外复制，我们将检查超微结构的位置， 细胞内细菌的生理环境，以及宿主 细胞对细胞内感染的反应。 它们会试图繁殖 spv介导的无细胞培养基中的生长，并最终阐明 毒力质粒介导生长的细菌生理学。 这些研究将阐明spv基因的致病机制， 鉴定相关的染色体毒力基因，并鉴定宿主防御 抵抗细胞内细菌生长。 分析了 宿主和病原体在细胞内生长的研究将导致关于 沙门氏菌引起全身性疾病的机制，以及其他 胞内细菌病原体。