Bacterial inhibitors of eukaryotic membrane fusion

真核细胞膜融合的细菌抑制剂

基本信息

批准号：
8600238
负责人：
Vincent Joseph Starai
金额：
$ 33.41万
依托单位：
UNIVERSITY OF GEORGIA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-01-01 至 2017-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8600238
关键词：
Air Conditioning Alveolar Macrophages Anti-Bacterial Agents Antibiotic Therapy Bacterial Proteins Binding Biochemical Biochemical Process Biochemistry Biological Models Cells Contracts Data Development Disease Disease Outbreaks Elderly Endosomes Environment Event Future Glean Goals Health Human In Vitro Individual Infection Infective endocarditis Intracellular Membranes Invaded Laboratories Lead Legionella Legionella pneumophila Legionnaires&apos Disease Liposomes Lysosomes Membrane Membrane Fusion Membrane Protein Traffic Methods Microbiology Modeling Modification Molecular Molecular Target Molecular and Cellular Biology Pathogenesis Pathway interactions Patient Care Patients Phagosomes Pneumonia Process Proteins Qualifying Reaction Recombinants Reporting Research SNAP receptor Saccharomyces cerevisiae System Testing United States Vacuole Yeasts biochemical model in vivo inhibitor/antagonist insight microorganism pathogen pathogenic bacteria protein structure public health relevance receptor research study respiratory yeast protein

项目摘要

DESCRIPTION (provided by applicant): Legionella pneumophila (Lpn) causes a severe, sometimes fatal, form of pneumonia known as Legionnaires' disease (LD). It is estimated that up to 50,000 individuals in the United States contract LD every year, with up to 18,000 of these patients being hospitalized. These numbers likely underestimate the total number of infections, however, due to a consistent lack of reporting. While most healthy individuals recover completely from their infections with appropriate antibiotic treatment, elderly and extremely young patients can succumb to this disease, with up to 30% of hospitalized patients succumbing to this respiratory pathogen during various outbreaks. Therefore, a deeper understanding of the mechanisms by which Lpn can invade cells to cause disease is desirable, and could help promote new treatments for Lpn outbreaks and infections. Our goals are to study the mechanisms through which Lpn alters its host cell environment. Lpn produces and secretes a number of bacterial proteins that modulate normal eukaryotic processes, and we propose focusing on those proteins which modulate eukaryotic intracellular membrane fusion. Lpn's ability to inhibit or alter eukaryotic intracellular membrane fusion pathways is a critical component of its pathogenic capacity, thereby enabling this microorganism to escape the host cell's front-line defense of lysosomal degradation. Therefore, identifying and characterizing the mechanisms by which Lpn alters eukaryotic membrane fusion and trafficking pathways will provide new insights into Lpn's ability to survive intracellularly, and into its disease-causing capabilities. Over the past 3 years, my laboratory has employed a powerful biochemical model of eukaryotic membrane fusion, the homotypic fusion of vacuoles from the yeast Saccharomyces cerevisiae (Sce), to begin the characterization of a protein from Lpn, LegC3, that is now shown to directly inhibit eukaryotic membrane fusion. We propose using this in vivo and in vitro Sce vacuole fusion system to continue studying LegC3, as well as 3 other similar proteins from Lpn, and will test the hypothesis that intracellular pathogenic bacteria, such as Lpn, can directly alter membrane fusion events through extremely conserved, eukaryotic core fusion machinery. By using powerful models of membrane fusion, we can begin to dissect the molecular mechanisms of Lpn pathogenesis. The three specific aims of this application are: Aim 1: Confirm and characterize the receptor(s) for the Lpn LegC3 protein. Aim 2: Elucidate the mechanism by which the Lpn LegC3 protein inhibits eukaryotic membrane fusion. Aim 3: Explore the function of the three additional Lpn coiled-coil proteins LegC2, LegC7, and IcmG/DotF from Sce. !

描述（由申请人提供）：嗜肺军团菌 (Lpn) 会导致一种严重的、有时甚至是致命的肺炎，称为军团病 (LD)。据估计，美国每年有多达 50,000 人感染 LD，其中多达 18,000 名患者住院治疗。然而，由于始终缺乏报告，这些数字可能低估了感染总数。虽然大多数健康个体通过适当的抗生素治疗可以完全从感染中恢复，但老年和极年幼的患者可能死于这种疾病，在各种疫情爆发期间，高达 30% 的住院患者死于这种呼吸道病原体。因此，更深入地了解 Lpn 侵入细胞导致疾病的机制是必要的，并且可能有助于促进针对 Lpn 爆发和感染的新治疗方法。我们的目标是研究 Lpn 改变宿主细胞环境的机制。 Lpn 产生并分泌许多调节正常真核过程的细菌蛋白，我们建议重点关注那些调节真核细胞内膜融合的蛋白。 Lpn 抑制或改变真核细胞内膜融合途径的能力是其致病能力的关键组成部分，从而使该微生物能够逃脱宿主细胞溶酶体降解的前线防御。因此，识别和表征 Lpn 改变真核细胞膜融合和运输途径的机制将为 Lpn 在细胞内生存的能力及其致病能力提供新的见解。在过去的 3 年里，我的实验室采用了强大的真核膜融合生化模型，即来自酿酒酵母 (Sce) 的液泡的同型融合，开始表征来自 Lpn、LegC3 的蛋白质，该蛋白质现在被证明可以直接抑制真核细胞膜融合。我们建议使用这种体内和体外 Sce 液泡融合系统继续研究 LegC3 以及来自 Lpn 的其他 3 种类似蛋白，并将检验细胞内致病菌（如 Lpn）可以通过极端的方式直接改变膜融合事件的假设。保守的真核核心融合机制。通过使用强大的膜融合模型，我们可以开始剖析 Lpn 发病机制的分子机制。本申请的三个具体目标是：目标 1：确认并表征 Lpn LegC3 蛋白的受体。目标 2：阐明 Lpn LegC3 蛋白抑制真核细胞膜融合的机制。目标 3：探索来自 Sce 的另外三种 Lpn 卷曲螺旋蛋白 LegC2、LegC7 和 IcmG/DotF 的功能。！