CELL TO CELL SIGNALING IN MYCOBACTERIA

描述（由申请人提供）：结核分枝杆菌（MTB）是结核病（TB）的病原体，感染全球17亿人。每年有200万至300万人最终死于结核病。随着有效抗结核药物的发现，结核病得以治愈。然而，多重耐药结核病和最近出现的广泛耐药结核病，在许多情况下是无法治愈的，有可能使结核病再次成为不治之症。艾滋病毒/艾滋病加剧了结核病的流行。参与MTB许多表型调节的因素，如毒力、潜伏期、抗生素耐药性和在恶劣条件下生存的能力还不清楚。三十年前发现的细菌细胞密度依赖性信号传导（群体感应）已被证明在控制细菌的毒力、孢子形成、抗生素产生、对恶劣条件的抗性、细胞分裂、生物膜发育和耐药性中发挥重要作用。关于群体感应在MTB表型调节中的作用的数据有限。群体感应相关基因的分离和鉴定为理解和改变细菌生理学提供了新的途径。在拟议的研究中，我们的广泛目标是识别和表征分枝杆菌中参与细胞间信号传导的基因。具体目的包括：（1）利用遗传学技术研究菱形样蛋白在分枝杆菌生理学中的作用。这将通过M中菱形样基因（其他生物中的群体感应基因）的失活来实现。并确定其如何影响分枝杆菌的信号产生、形态、存活和其他表型。（二）、构建分枝杆菌群体感应调控融合基因文库。这一目标将确定分枝杆菌基因的调控是细胞密度依赖性。这将通过在M中构建随机lacZ报告转录基因融合体来解决。耻垢染色体(3)探讨分枝杆菌群体感应调节基因融合体的调控途径。这将通过筛选改变目标2中鉴定的群体感应调节的lacZ基因融合体的表达的其他基因来实现。本研究将提供有关群体感应调控分枝杆菌功能的进一步信息，并描述调控途径。这将丰富我们对分枝杆菌生物学的知识，并可能揭示新的药物和疫苗靶点。

DESCRIPTION (provided by applicant): Mycobacterium tuberculosis (MTB), the causative agent of tuberculosis (TB), infects 1.7 billion people worldwide. Each year, 2-3 million will eventually die of TB. With the discovery of effective anti-tuberculosis drugs, TB became curable. However, Multi Drug Resistant TB and the recent appearance of extensive drug resistant TB, which in many cases is untreatable, has the potential to make TB an incurable disease once again. The TB epidemic has been worsened by HIV/AIDS. Factors involved in the regulation of many phenotypes of MTB such as virulence, latency, antibiotic resistance and ability to survive under harsh conditions are not well understood. Bacterial cell density dependent signaling (quorum sensing), discovered three decades ago, has been shown to play a major role in the control of virulence, sporulation, antibiotic production, resistance to harsh conditions, cell division, biofilm development and drug resistance in bacteria. Data on the role of quorum sensing on the regulation of MTB phenotypes are limited. The isolation and characterization of genes involved in quorum sensing offer a novel approach in understanding and modifying bacterial physiology. In the proposed study, our broad objective is to identify and characterize genes involved in cell-to-cell signaling in mycobacteria. The specific objectives include: (1) To use genetic techniques to study the role of the Rhomboid-like proteins in the physiology of mycobacteria. This will be achieved by inactivation of rhomboid like genes (quorum sensing genes in other organisms) in M. smegmatis and determining how this affects signal production, morphology, survival and other phenotypes of mycobacteria. (2). To construct a library of quorum sensing regulated gene fusions in mycobacteria. This objective will identify the mycobacterial genes whose regulation is cell density dependent. This will be addressed through construction of random lacZ reporter transcriptional gene fusions in M. smegmatis chromosome. (3) To examine the regulatory pathways of the quorum sensing regulated gene fusions in mycobacteria. This will be achieved through screening for other genes that alter the expression of quorum sensing regulated lacZ gene fusions identified in objective 2. This study will provide further information on quorum sensing regulated mycobacterial functions and also describe the regulatory pathways. This will enrich our knowledge on mycobacterial biology and may reveal novel drug and vaccine targets.