Mycobacterium tuberculosis Survival Regulatory Genes

结核分枝杆菌生存调节基因

• 批准号: 7337636
• 负责人: WILLIAM Ramses BISHAI
• 金额: $ 38.02万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7337636
• 关键词: Address; Asia; Attenuated Live Virus Vaccine; Bacteriophages; Binding; Biochemical; Cluster Analysis; Communicable Diseases; Complement; Condition; Consensus; Count; DNA-Directed RNA Polymerase; Data; Defect; Dependence; Diagnostic; Disease; Disease Progression; Distal; Environment; Funding; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Genus Mycobacterium; Immune response; Infection; Interferon Type II; Kinetics; Knock-out; Lung; Lung diseases; Mediating; Mediator of activation protein; Microarray Analysis; Molecular Genetics; Molecular Profiling; Monitor; Mus; Mycobacterium tuberculosis; Nitric Oxide; Organism; Oxidases; Pathogenesis; Pathologic; Patients; Phagocytes; Pharmaceutical Preparations; Phenotype; Pre-study; Regulator Genes; Regulon; Resistance; Role; Sigma Factor; Specificity; Staging; Stress; Time; Tuberculosis; Tumor Necrosis Factor-alpha; Vaccination; Vaccines; Virulence; acetamidase; attenuation; human TNF protein; immunopathology; mortality; mouse model; mutant; mycobacterial; novel; promoter; response

DESCRIPTION (provided by applicant): Mycobacterium tuberculosis is a leading AIDS-related infectious disease killer worldwide. Tuberculosis is a disease of multiple pathologic stages, and hence M. tb. must possess multiple adaptive genetic strategies to survive in these differing environments. Understanding the organism's pathogenesis mechanisms during these disease stages is the surest way to develop better diagnostics, vaccines, and drugs which are critically needed for patients with TB and TB/HIV. We have genetically interrupted 5 M. tb. sigma factor genes, identified the genes which they regulate by using microarray technology and assessed their virulence in mice. Among these alternative sigma factors there is functional redundancy in that upon infection of mice 4 of the 5 mutants show the immunopathology phenotype of attenuation in which mycobacterial counts are maintained at high level but there is a significant delay in mortality and in disease progression in the lungs. In the first aim, we will explore the immunopathology defect demonstrated by several of the sigma factor knockout mutants. The roles of known mediators of TB control such as nitric oxide, TNF-alpha, interferon-gamma and phagocyte oxidase will be examined using the M. tb. deltasigH and other knockout mutants which display the immunopathology phenotype. Second, we will refine our understanding of these sigma factor regulons by studying expression profiles under stress conditions, by biochemical analysis of transcription, by constructing double knockout mutants, and through conditional expression of sigma factors. We will address whether there is sufficient ECF promoter consensus degeneracy to permit redundant sigma factor control of dependent genes or whether there are distal mediators which remain to be discovered. Finally, in the 3rd aim we will explore the modulation of sigma factor activity by studying anti-sigma factors. We will study the effect of AsiA, a phage-encoded anti-sigma factor which binds to RNA polymerase, remodels it, and alters its promoter specificity. We will seek to determine whether AsiA or portions of it have a transcription-specificity modifying effect in mycobacteria. We will also study the role of a novel sigma factor-regulator in M. tb, Rv1364c, which our data show is required for resistance to SDS stress. Advancing our understanding ofM. tb sigma factors and their related regulators will help establish key adaptive mechanisms in the pathogenesis of TB.

描述（由申请人提供）：结核分枝杆菌是世界范围内与艾滋病相关的传染病的主要杀手。结核病是一种具有多个病理阶段的疾病，因此结核分枝杆菌。必须拥有多种适应性遗传策略才能在这些不同的环境中生存。了解这些疾病阶段的生物体发病机制是开发结核病和结核病/艾滋病毒患者急需的更好诊断方法、疫苗和药物的最可靠方法。我们已经从基因上中断了 5 M. tb。西格玛因子基因，通过使用微阵列技术鉴定了它们调节的基因，并评估了它们在小鼠中的毒力。 Among these alternative sigma factors there is functional redundancy in that upon infection of mice 4 of the 5 mutants show the immunopathology phenotype of attenuation in which mycobacterial counts are maintained at high level but there is a significant delay in mortality and in disease progression in the lungs.在第一个目标中，我们将探索几种西格玛因子敲除突变体所表现出的免疫病理学缺陷。 The roles of known mediators of TB control such as nitric oxide, TNF-alpha, interferon-gamma and phagocyte oxidase will be examined using the M. tb. deltasigH 和其他显示免疫病理学表型的敲除突变体。其次，我们将通过研究应激条件下的表达谱、转录的生化分析、构建双敲除突变体以及西格玛因子的条件表达来完善对这些西格玛因子调节子的理解。我们将解决是否存在足够的 ECF 启动子共有简并性以允许依赖基因的冗余西格玛因子控制，或者是否存在有待发现的远端介质。最后，在第三个目标中，我们将通过研究反西格玛因子来探索西格玛因子活性的调节。我们将研究 AsiA 的作用，AsiA 是一种噬菌体编码的抗 Sigma 因子，它与 RNA 聚合酶结合、重塑它并改变其启动子特异性。我们将寻求确定 AsiA 或其部分是否对分枝杆菌具有转录特异性修饰作用。我们还将研究 M. tb Rv1364c 中新型 sigma 因子调节剂的作用，我们的数据显示它是抵抗 SDS 应激所必需的。增进我们对M的理解。结核病西格玛因子及其相关调节因子将有助于建立结核病发病机制的关键适应性机制。