Exploration of quorum sensing in tuberculosis

结核病群体感应的探索

• 批准号: 10628011
• 负责人: Jeffrey D. Cirillo
• 金额: $ 19.28万
• 依托单位: TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10628011
• 关键词: Actinomycetales; Affect; Animals; Antibiotics; Bacteria; Binding; Cells; Characteristics; Communicable Diseases; Critical Pathways; Data; Disease; Environment; Epithelial Cells; Exposure to; Gene Expression; Gene Expression Regulation; Genes; Genome; Genus Mycobacterium; Goals; Growth; Homologous Gene; Human; Infection; Intervention; Length; Leprosy; Light; Link; Macrophage; Metabolism; Microbial Biofilms; Molecular; Muramidase; Mycobacterium avium; Mycobacterium fortuitum; Mycobacterium intracellulare; Mycobacterium kansasii; Mycobacterium leprae; Mycobacterium marinum; Mycobacterium tuberculosis; Mycobacterium ulcerans; Organic Chemistry; Pathogenesis; Pathway interactions; Phenotype; Pigments; Play; Population; Process; Production; Proteins; Regulation; Regulatory Pathway; Resuscitation; Role; Side; Signal Transduction; Signaling Molecule; Skin; Streptomyces; Streptomyces coelicolor; Streptomyces griseus; Structure; System; Toxin; Tuberculosis; Virulence; butyrolactone; density; experience; extracellular; genetic regulatory protein; human disease; insight; latent infection; lung pathogen; member; multidisciplinary; mycobacterial; novel; pathogen; prevent; quorum sensing; reactivation from latency; response; sensor; therapy development

PROJECT SUMMARY Mycobacterium are responsible for many important human diseases, including tuberculosis and leprosy. Bacterial species use inter-bacterial signaling or quorum sensing (QS) to coordinate gene regulation in response to their environment. Despite this fact and the presence of numerous QS molecule responsive regulators (LuxR homologues) in all mycobacterial genomes sequenced, no quorum sensing molecules have been identified in any mycobacterial species. The only potential signaling molecule yet identified is resuscitation promoting factor (Rpf) that is a lysozyme-like protein that can stimulate reactivation of latent tuberculosis. As an exploratory project, we set out in search of the best way to identify QS molecules from mycobacteria. Most likely due to the extremely low concentrations of QS molecules required to signal, nearly all QS molecules have been identified through use of a sensor strain that produces light or pigment upon exposure to QS molecules. Since most bacterial sensor strains are Gram negatives, making it unsurprising that they have not been used successfully to identify mycobacterial QS molecules, we searched for a new sensor system. We reasoned that a sensor based on Streptomyces, an Actinomycetales closely related to Mycobacterium, would be likely to respond to mycobacterial QS molecules. In our preliminary studies, we found that Streptomyces griseus and S. coelicolor can respond to mycobacterial QS molecules. The use of a novel QS sensor strain allowed us to purify two of these molecules, designated MAI-1 and MAI-2, determine partial structure for MAI-1 and demonstrate impacts of MAI-1 and MAI-2 on virulence-related phenotypes. In this application we propose to further analyze the QS pathways in mycobacteria to determine their role in pathogenesis. This will be accomplished through two specific aims: 1) Identification of mycobacterial QS molecules. Our working hypothesis is that mycobacterial QS molecules are structurally related to γ- butyrolactone (GBL) QS molecules in Streptomyces. Our preliminary studies demonstrate that MAI-1 and MAI-2 can trigger QS pathways in S. coelicolor, suggesting that they are related to each other and to GBLs, but we have not yet fully determined their structures. In this aim, we will utilize our novel sensor to determine their structures and confirm their ability to function as signaling molecules. 2) Dissect the mechanisms of QS signaling in mycobacteria. Our working hypothesis is that MAI-1 and MAI-2 are made by mycobacteria to control gene expression in density-dependent fashion. Our preliminary studies developed a screen for production of MAI molecules by mycobacteria and found that MAI molecules enhance biofilm formation, colonization of epithelial cells and macrophages and growth in macrophages. We will analyze the pathways involved in synthesis of these QS molecules in mycobacteria. The overall goal of these studies is to understand how these QS molecules are made and affect the ability of mycobacteria to cause disease.

项目概要 分枝杆菌是许多重要的人类疾病的罪魁祸首，包括结核病和麻风病。 细菌物种利用细菌间信号传导或群体感应（QS）来协调基因调控 对他们的环境的反应。尽管存在这一事实并且存在大量 QS 分子响应 所有已测序的分枝杆菌基因组中都存在调节因子（LuxR 同源物），没有群体感应分子 已在任何分枝杆菌物种中被鉴定。迄今为止唯一确定的潜在信号分子是 复苏促进因子 (Rpf)，是一种溶菌酶样蛋白，可以刺激潜伏细胞的重新激活 结核。作为一个探索性项目，我们开始寻找识别 QS 分子的最佳方法 分枝杆菌。很可能是由于发出信号所需的 QS 分子浓度极低，几乎 所有 QS 分子均已通过使用产生光或色素的传感器菌株进行识别。 暴露于 QS 分子。由于大多数细菌传感器菌株是革兰氏阴性菌，因此这并不奇怪 由于它们尚未成功用于识别分枝杆菌 QS 分子，我们寻找了一种新的 传感器系统。我们推断基于链霉菌的传感器，链霉菌是一种与 分枝杆菌可能会对分枝杆菌 QS 分子产生反应。在我们的初步研究中，我们 发现灰色链霉菌和天蓝色链霉菌可以对分枝杆菌 QS 分子做出反应。使用 一种新型 QS 传感器菌株使我们能够纯化其中两种分子，命名为 MAI-1 和 MAI-2，确定 MAI-1 的部分结构并证明 MAI-1 和 MAI-2 对毒力相关表型的影响。在 在本申请中，我们建议进一步分析分枝杆菌中的 QS 途径，以确定它们在 发病。这将通过两个具体目标来实现：1) 分枝杆菌 QS 的鉴定 分子。我们的工作假设是分枝杆菌 QS 分子在结构上与 γ- 链霉菌中的丁内酯 (GBL) QS 分子。我们的初步研究表明 MAI-1 和 MAI-2 可以触发 S. coelicolor 中的 QS 通路，表明它们彼此相关并与 GBL 相关， 但我们还没有完全确定它们的结构。为此，我们将利用我们的新型传感器来确定 它们的结构并确认它们作为信号分子发挥作用的能力。 2）剖析机制 分枝杆菌中的 QS 信号传导。我们的工作假设是 MAI-1 和 MAI-2 由分枝杆菌产生 以密度依赖性方式控制基因表达。我们的初步研究开发了一个屏幕 分枝杆菌产生 MAI 分子，并发现 MAI 分子增强生物膜形成， 上皮细胞和巨噬细胞的定植以及巨噬细胞的生长。我们将分析路径 参与分枝杆菌中这些 QS 分子的合成。这些研究的总体目标是 了解这些 QS 分子是如何形成的以及如何影响分枝杆菌引起疾病的能力。