Mycobacterium tuberculosis Survival Regulatory Genes

结核分枝杆菌生存调节基因

• 批准号: 7166837
• 负责人: WILLIAM Ramses BISHAI
• 金额: $ 38.76万
• 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 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7166837
• 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）：结核分枝杆菌是全球主要的艾滋病相关传染病杀手。结核病是一种多病理阶段的疾病，因此M。TB.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。了解这些疾病阶段生物体的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的诊断方法、疫苗和药物的最可靠方法。我们在基因上中断了5 M。TB. sigma因子基因，通过使用微阵列技术鉴定它们调节的基因，并评估它们在小鼠中的毒力。在这些替代的σ因子中，存在功能冗余，因为在感染小鼠后，5种突变体中的4种显示出减毒的免疫病理学表型，其中分枝杆菌计数维持在高水平，但死亡率和肺部疾病进展显著延迟。在第一个目标中，我们将探索由几个sigma因子敲除突变体所证明的免疫病理学缺陷。结核控制的已知介质如一氧化氮、TNF-α、干扰素-γ和吞噬细胞氧化酶的作用将使用M。TB. deltasigH和其它显示免疫病理表型的敲除突变体。其次，我们将通过研究应激条件下的表达谱，通过转录的生化分析，通过构建双敲除突变体，以及通过条件性表达sigma因子来完善我们对这些sigma因子调节子的理解。我们将讨论是否有足够的ECF启动子共识简并允许冗余西格玛因子控制的依赖基因或是否有远端介质仍有待发现。最后，在第三个目标中，我们将通过研究反西格玛因素来探索西格玛因素活动的调节。我们将研究AsiA的作用，AsiA是一种噬菌体编码的抗σ因子，它与RNA聚合酶结合，重塑RNA聚合酶，并改变其启动子特异性。我们将试图确定AsiA或其部分是否在分枝杆菌中具有转录特异性修饰作用。我们还将研究一种新的西格玛因子调节剂在M。tb，Rv 1364 c，我们的数据表明，这是所需的抗SDS胁迫。加深对M的理解。tb sigma因子及其相关调节因子将有助于建立结核病发病机制中的关键适应机制。