Cell Biology of Mycobacterium tuberculosis Infection

结核分枝杆菌感染的细胞生物学

• 批准号: 7154156
• 负责人: DAVID G RUSSELL
• 金额: $ 48.11万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7154156
• 关键词: ATP-Binding Cassette Transporters; Address; Africa South of the Sahara; Bacillus (bacterium); Bacteria; Biogenesis; Biological Assay; Cathepsins B; Cells; Cellular biology; Ceramides; Cessation of life; Chronic; Consensus; Diagnostic; Documentation; Drug Delivery Systems; Environment; Genes; Genetic Screening; Genus Mycobacterium; HIV Infections; Hypersensitivity skin testing; Immune; Immunoglobulin G; Infection; Integration Host Factors; Lead; Lipids; Literature; Lysosomes; Maps; Membrane; Membrane Fusion; Membrane Lipids; Mutation; Mycobacterium tuberculosis; Nutrient; Outcome; Phagosomes; Phosphatidylinositols; Phosphorylation; Physiology; Planets; Population; Procedures; Process; Protein Kinase; Proteins; Recruitment Activity; Recycling; Regulation; Series; Sorting - Cell Movement; Source; Specificity; Sphingosine; System; Time; Tuberculosis; Vacuole; World Health Organization; bactericide; design; killings; macrophage; mutant; pathogen; prevent; research study; success; tool

DESCRIPTION (provided by applicant): The success of Mycobacterium tuberculosis, and other pathogenic mycobacteria species, lies in their ability to modulate their phagosome and prevent it from differentiating into an acidic, hydrolytically-competent compartment. The consensus in the field is that the bacterium arrests the normal maturation process leading to retention of the vacuole within the cell's recycling/sorting endosomal system. Although many studies detail the presence or absence of host molecules implicated in control of membrane fusion, the mechanism by which the bacterium modulates the phagosome remain to be determined. This proposal describes an integrated series of projects that will address this issue, place it in the context of the normal maturation process for phagosomes, and determine the consquences to the bacterium if it is delivered to the lysosome. The proposal addresses the following three aims: 1. Analysis of the lipid constituents of the phagosome membrane during maturation of IgG-bead and M. tuberculosis-containing phagosomes. The phosphorylation status of several membrane lipids changes during phagosome biogenesis and these alterations drive the association with the membrane fusion machinery in the cell. We intend to map these changes and correlate them with phenotypic differences in the pathogen-containing compartment. 2. Isolation and characterization of M. tuberculosis mutants defective in modulation of the phagosome. We have developed a genetic screen for such mutants and are currently characterizing the genetic defects that prevent modulation of the phagosome. These mutants should provide the tools that we need to determine how the bacterium regulates its phagosome. 3. Identification of lysosomal constituents that are bactericidal to M. tuberculosis. We have found that isolated lysosomes kill M. tuberculosis when added to bacterial cultures. Preliminary characterization of this fraction suggests that the activity co-purifies with cathepsins S and B. We intend to identify the active component and characterize the mechanism that leads to bacterial death.

描述（由申请人提供）：结核分枝杆菌的成功和其他致病性分枝杆菌物种在于它们调节吞噬体并防止其分化为酸性，水解且能兼容的室室的能力。该领域的共识是，细菌阻止了正常的成熟过程，从而导致液泡在细胞的回收/排序内体系统中保留。尽管许多研究详细介绍了与控制膜融合有关的宿主分子的存在或不存在，但细菌调节吞噬体的机制仍有待确定。该提案描述了一系列集成的项目，该项目将解决此问题，将其置于吞噬体正常成熟过程的背景下，并确定细菌对溶酶体的关注。该提案涉及以下三个目的：1。在IgG珠和含结核分枝杆菌的吞噬体成熟过程中对吞噬体膜的脂质成分的分析。吞噬体生物发生过程中几种膜脂质的磷酸化状态发生变化，这些改变促使与细胞中的膜融合机械相关。我们打算映射这些变化，并将它们与含病原体隔室中表型差异相关联。 2。结核分枝杆菌突变体的分离和表征在调节吞噬体时有缺陷。我们已经为这种突变体开发了一个遗传筛选，目前正在表征防止吞噬体调节的遗传缺陷。这些突变体应提供我们需要确定细菌如何调节其吞噬体的工具。 3。鉴定结核分枝杆菌的溶酶体成分。我们发现，当添加到细菌培养物中时，分离的溶酶体杀死结核分枝杆菌。这一部分的初步表征表明活性与组织蛋白酶S和B共同绘制。我们打算识别活性成分并表征导致细菌死亡的机制。