Remodeling of the M. tuberculosis cell wall by the host microenvironment

宿主微环境对结核分枝杆菌细胞壁的重塑

• 批准号: 7914752
• 负责人: Jordi B Torrelles
• 金额: $ 25.8万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7914752
• 关键词: Acetates; Affect; Alveolar; Alveolar Macrophages; Alveolus; Award; Bacillus (bacterium); Bacteria; Biochemical; Bronchoalveolar Lavage Fluid; Cell Wall; Cells; Cellular biology; Cytolysis; Data Quality; Deposition; Drug Delivery Systems; Ensure; Environment; Epithelial; Epithelial Cells; Genus Mycobacterium; Glucose; Homeostasis; Human; Hydrolase; Immune; Immune response; Infection; Label; Lung; Mass Spectrum Analysis; Metabolism; Methods; Modification; Molecular; Mycobacterium tuberculosis; Myeloid Cells; Pathway interactions; Pulmonary Surfactants; Radiolabeled; Shapes; Source; Staining method; Stains; Surface; Terminal Bronchiole; The Sun; United States National Institutes of Health; Virulent; base; cell envelope; improved; in vitro Model; macrophage; mass spectrometer; monocyte; neutrophil; novel; pathogen; pressure; radiotracer; receptor; research study; response; surfactant; transmission process

When Mycobacterium tuberculosis (M.tb) infection occurs by airiaorne transmission, bacilli are deposited in the alveolar spaces of the lungs. Within the alveolar space and proximal to it exist a number of innate immune mechanisms that are critical in maintaining pulmonary homeostasis. M.tb, a highly host-adapted intracellular pathogen of macrophages, may use these mechanisms to its advantage during infection. Little is known about how M.tb is affected by the immune pressure that it encounters in the alveolar microenvironment outside of the macrophage. In addition to alveolar macrophages, major constituents of lung defense in the alveolar space are type I and II epithelial cells, monocytes, and neutrophils, and their secreted products to the alveolar lumen (I.e., surfactant). Each of these alveolar compartment cells contains its own unique array of hydrolases that are released to the alveolar environment and sequestered in surfactant. When M.tb is initially deposited in the terminal bronchioles and alveoli, as well as following release from lysed macrophages, the bacilli are in close contact with these hydrolases. During the K99/R00 NIH Pathway to Independence Award, Dr. Torrelles will examine the effects of the human alveolar environment on the cell envelope of M.tb and how these effects dictate the fate of M.tb within the host. Using labeled virulent M.tb H37Rv and/or M.tb Erdman, and biochemical, molecular and cell biology approaches, we propose: 1) To characterize specific hydrolases derived from alveolar compartment cells and pulmonary surfactant that affect the cell envelope of virulent M.tb. To ensure that the studies remain focused, we will prioritize candidate hydrolases and restrict our experiments to the study of the 3-5 hydrolases in total; 2) To characterize the effects of our selected human lung hydrolases on the integrity of the virulent M.tb cell envelope; and 3) To determine how hydrolase-derived modifications on the cell envelope of virulent M.tb affect the bacillus sun/ival within alveolar compartment cells.

当结核分枝杆菌(M.tb)通过主动脉传播时，细菌会沉积在肺的肺泡腔中。在肺泡腔及其近端存在着许多先天免疫机制，这些机制对维持肺内环境的稳定至关重要。结核分枝杆菌是一种高度适应宿主的巨噬细胞内病原体，在感染过程中可能会利用这些机制来发挥优势。关于结核分枝杆菌在巨噬细胞外的肺泡微环境中如何受到免疫压力的影响，人们知之甚少。除肺泡巨噬细胞外，肺泡腔内肺防御的主要成分是I型和II型上皮细胞、单核细胞和中性粒细胞，以及它们分泌到肺泡腔的产物(即表面活性物质)。这些肺泡室细胞中的每一个都含有自己独特的水解酶阵列，这些水解酶被释放到肺泡环境中并隔离在表面活性物质中。当结核分枝杆菌最初沉积在终末细支气管和肺泡，以及随后从裂解的巨噬细胞释放出来时，细菌与这些水解酶密切接触。在K99/R00美国国立卫生研究院独立奖期间，Torrelles博士将研究人类肺泡环境对结核分枝杆菌细胞膜的影响，以及这些影响如何决定结核分枝杆菌在宿主内的命运。利用标记的结核分枝杆菌H37Rv和/或结核分枝杆菌Erdman，以及生化、分子和细胞生物学方法，我们建议：1)鉴定来自肺泡室细胞的特定水解酶和肺表面活性物质对毒力结核分枝杆菌细胞膜的影响。为了确保研究的重点，我们将优先考虑候选水解酶，并将我们的实验限制在总共3-5个水解酶的研究上；2)表征我们选择的人肺水解酶对强毒结核分枝杆菌细胞膜完整性的影响；以及3)确定对强毒结核分枝杆菌细胞膜的水解酶修饰如何影响肺泡室细胞内的杆菌SUN/IVAL。