M.tuberculosis Genes Regulating Persistent Infection

描述(由申请人提供) 结核病是世界上最主要的死亡原因之一。 这种病毒是一种传染性物质，每年造成300多万人死亡。 分枝杆菌感染者的高死亡率 肺结核的部分原因是它能够寄生巨噬细胞和 在宿主中建立长期、持续的感染，尽管是细胞介导的 豁免权。尽管目前的抗结核药物库在 治疗活动性疾病的患者，这些药物是 在治疗目前患有潜伏性肺炎的20亿人方面无效 结核病，或感染多重耐药的M。 肺结核。一组转录调控决定因素可能 在与结核分枝杆菌相关的过程中发挥关键作用 双组分信号转导系统。这些系统调解 适应过程，并已被证明有助于毒力和 在其他生物体中引发疾病。这项研究的目标是 进一步描述结核分枝杆菌二组分系统(MprA-MPRB) 这是建立和维护持久的 感染。在这项提案中，我们计划：(I)确定和描述 受MprA转录因子调控的基因。受MprA调控的基因 将通过生化方法从结核分枝杆菌染色体中鉴定出 丰富和遗传选择技术，并将以基因为特征 模型系统中的失活、启动子表达分析和评估 用来治疗感染。(Ii)分析MprA的体内表达谱 反应调节因子，以及MprA调控的基因。这将是 通过使用GFP报告对这些基因的表达进行分析 技术、引物延伸分析、分子信标技术和DNA 在生理相关条件下的基于微阵列的分析。(Iii) 描述MprA去调控对宿主-病原体相互作用的影响。 这将通过检查MprA缺失或过度表达的影响来实现 关于结核分枝杆菌毒力的研究。毒力研究将包括细菌 体外组织存活和细胞因子表达分析 感染的培养系统和动物模型系统。这些研究将 同时也阐述了MprA去调节对牛分枝杆菌卡介苗的影响。 衰减。这里概述的建议预计将改善我们的 了解结核分枝杆菌致病所需的基因，并帮助 更好地界定M遇到的条件和利用的应对措施。 感染潜伏期的结核病。我们希望这一分析 双组分系统的研究将有助于基因的鉴定 可以为其开发新型抗结核药物的决定因素。

DESCRIPTION (provided by applicant) Tuberculosis is the leading cause of death in the world from a single infectious agent, and is responsible for more than 3 million deaths annually. The high mortality rate in individuals infected with Mycobacterium tuberculosis is due in part to its ability to parasitize macrophages and establish long-term, persistent infection in the host despite cell-mediated immunity. Although the current anti-tubercular drug arsenal is effective in treating individuals suffering from active disease, these drugs are ineffective in treating the 2 billion people that currently suffer from latent tuberculosis, or that are infected with multi-drug resistant strains of M. tuberculosis. One group of transcriptional regulatory determinants that may play a critical role in processes associated with M. tuberculosis latency is the two-component signal transduction systems. These systems mediate adaptation processes and have been shown to contribute to virulence and disease elicitation in other organisms. The goals of this study are to characterize further a two-component system of M. tuberculosis (MprA-MprB) that is required for the establishment and maintenance of persistent infection. In this proposal, we plan to: (i) Identify and characterize the genes regulated by the MprA transcription factor. The genes regulated by MprA will be identified from the M. tuberculosis chromosome using biochemical enrichment and genetic selection techniques, and will be characterized by gene inactivation, promoter expression analysis, and evaluation in model systems for infection. (ii) Analyze the in vivo expression profile of the MprA response regulator, and the genes regulated by MprA. This will be accomplished by expression analysis of these genes using GFP reporter technology, primer extension analysis, molecular beacon technology, and DNA microarray based analysis under physiologically relevant conditions. (iii) Delineate the effects of MprA de-regulation on host-pathogen interactions. This will be accomplished by examining effects of MprA loss or overexpression on M. tuberculosis virulence. Virulence studies will include bacterial survival and cytokine expression analysis as assayed in in vitro tissue culture systems and animal model systems of infection. These studies will also address the effects of MprA de-regulation on Mycobacterium bovis BCG attenuation. The proposal outlined here is expected to improve our understanding of genes required by M. tuberculosis for pathogenesis, and help better define the conditions encountered and responses utilized by M. tuberculosis during the latent stage of infection. We hope that the analysis of two-component systems will aid in the identification of genetic determinants for which novel anti-tubercular drugs can be developed.