Legionella pneumophila developmental cycle & virulence

嗜肺军团菌发育周期

• 批准号: 7330345
• 负责人: PAUL Stokes HOFFMAN
• 金额: $ 37.02万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-12-15 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7330345
• 关键词: A/J Mouse; Acute; Acute Pneumonia; Aerosols; Amoeba genus; Animal Model; Antibiotics; Bacteria; Biochemical; Biocide; Biological Assay; Biology; Burkholderia; Cataloging; Catalogs; Cell membrane; Cells; Collaborations; Condition; Coxiella; Cyst; Defect; Detection; Detergents; Development; Disease; Early Endosome; Elderly; Electron Microscopy; Environment; Environmental Risk Factor; Fractionation; Gel; Gene Expression; Gene Fusion; Genes; Genus Mycobacterium; Goals; Green Fluorescent Proteins; Growth; Habitats; Health; Health Hazards; Heating; Hela Cells; Human; Immunocompromised Host; In Vitro; Infection; Invaded; Knowledge; L Forms; Lead; Legionella pneumophila; Legionnaires' Disease; Lethal Dose 50; Letters; Light; Lung; Measures; Membrane; Modeling; Morphogenesis; Mutation; Natural Immunity; Parasites; Pathogenesis; Pathology; Peroxides; Persons; Physiologic pulse; Pneumonia; Polymerase Chain Reaction; Production; Proteins; Proteome; Protocols documentation; Protozoa; Pulse taking; Radiolabeled; Range; Regulator Genes; Reporter; Research; Research Personnel; Resistance; Risk; Role; Simulate; Source; Staging; Staining method; Stains; Suspension substance; Suspensions; Temperature; Testing; Tetrahymena; Virulence; Virulent; Water; base; chlorination; design; disease transmission; genetic analysis; human disease; improved; insight; macrophage; microbial; mouse model; mutant; nutrition; pathogen; periplasm; programs; protein function; protein structure; radiotracer; resilience; trafficking; transmission process

Legionella pneumophila (L. pneumophila) resides in aquatic habitats as an intracellular parasite of protozoa and when transmitted in aerosols to susceptible humans, produces an acute pneumonia known as Legionnaires' disease. Transmission of this disease is always one-way - from the environment to humans, and despite 30 years of research, an explanation for why this disease is not spread from person to person has not been offered. We have documented a developmental cycle in cell based infection models in which vegetative bacteria differentiate into cyst-like metabolically dormant forms that are resilient and highly infectious. These cysts are resistant to the effects of antibiotics, detergents and other toxic agents and can persist in water sources for extended periods where they present a health hazard. To determine if these cysts are responsible for transmission of Legionnaires' disease we propose the following aims: 1) To develop infection models in protozoa and in tap water to identify environmental conditions that promote cyst morphogenesis with sub aims of (i) tracking morphogenesis by light and electron microscopy; (i) by reporter gene fusions; (iii) pulse chase radiolabeling and proteome profiling and (iv)to assess cyst forms for resilience to detergents, biocides, and antibiotics; and infectiousness for amoebae and A/J mouse macrophages. 2) Assessment of virulence of cysts in an A/J mouse aerosol challenge model; and 3) To characterize the cyst like forms arising from protozoa,water and HeLa cells by (i) 2D gel proteome profiling for unique proteins, (ii)cyst fractionation studies to identify proteins of the outer membrane, periplasm and cytoplasmic membrane and (iii) use a mutation based approach to study developmentally regulated genes and regulatory factors. We anticipate that continued study of the planktonic cysts will contribute significant new knowledge to our understanding of the biology, pathogenesis, persistence and transmission of Legionnaires' disease. Relevance to human health. Legionnaires' disease is a rapidly growing health risk world wide, and especially for the elderly and immunocompromised. The knowledge gained from these studies should lead to improved detection and control measures that reduce the risk to humans. These studies should also provide insights relevant to other opportunistic environmental pathogens including oxiella, Burkholderia and species of Mycobacterium.

肺炎军团菌（L. pneumophila）居住在水生栖息地中，作为原生动物的细胞内寄生虫 当在气溶胶中传输到易感人类时，会产生一种急性肺炎 军团病。这种疾病的传播始终是单向的 - 从环境到人类， 尽管进行了30年的研究，但解释了为什么这种疾病不会从人到人传播 尚未提供。我们已经记录了基于细胞的感染模型中的发展周期 营养细菌分化为囊肿的代谢休眠形式，这些形式具有弹性且高度 感染力。这些囊肿对抗生素，洗涤剂和其他有毒剂的影响具有抗性，并且可以 持续存在较长时期的水源，它们会带来健康危害。确定这些是否 囊肿负责传播军团疾病，我们提出以下目的：1）发展 原生动物和自来水中的感染模型，以识别促进囊肿的环境条件 （i）通过光和电子显微镜跟踪形态发生的子形态发生； （i）记者 基因融合； （iii）脉冲追逐放射性标记和蛋白质组分析和（iv）评估囊肿形式的 对洗涤剂，杀菌剂和抗生素的韧性；以及对Amoebae和A/J鼠标的传染性 巨噬细胞。 2）评估A/J小鼠气溶胶挑战模型中囊肿的毒力；和3）到 （i）2D凝胶蛋白质组分析表征原生动物，水和HeLa细胞产生的囊肿形式 对于独特的蛋白质，（ii）囊肿分馏研究以鉴定外膜的蛋白质，周质和 细胞质膜和（iii）使用基于突变的方法来研究发育调控的基因 和监管因素。我们预计继续研究浮游囊肿将有效 新知识以理解生物学，发病机理，持久性和传播 军团病。与人类健康有关。军团疾病是一种快速增长的健康风险 全世界，尤其是对于老年人和免疫功能低下的人。从这些中获得的知识 研究应导致改进的检测和控制措施，以降低对人类的风险。这些 研究还应提供与其他机会主义环境病原体有关的见解 Oxiella，Burkholderia和分枝杆菌的物种。