Investigating genetic regulators of Mycobacterium tuberculosis cell division and their role in persistent tuberculosis infection

项目总结/摘要 结核分枝杆菌（Mtb）是结核病的病原体，已感染了约四分之一的 全球人口，每年杀死100多万人。结核分枝杆菌是一种非常成功的人类病原体 很大程度上是因为细菌可以适应承受体内几种不同的压力， Mtb可以持续数月至数年的复制静止期。这给治疗带来了重大挑战 正如许多抗结核药物靶向细菌复制和细胞壁合成一样，结核病有一个独特的 细菌不对称生长并产生大小不等的子细胞的分裂机制， 生长速率和细胞壁组成。这与其他研究充分的细胞分裂过程形成对比。 细菌和Mtb具有不同的细胞机制和调节途径来协调它们的细胞分裂。 因此，了解结核分枝杆菌独特的复制机制、如何调控以及如何促进结核分枝杆菌的复制是至关重要的。 细菌致病机理的研究该提案的总体目标是阐明两个新的调控网络， 控制Mtb细胞分裂，并了解这种调节在结核病感染过程中的作用， 减缓或停止其生长。我假设未表征的转录因子WhiA和WhiB 2是 Mtb细胞分裂的重要调节因子，并且这两种蛋白质都是维持细菌活力所必需的 在体内，即使在持续性结核感染期间，当细菌进入缓慢或非复制状态时。这 该提案寻求i）在Mtb中利用新的CRISPR干扰技术来询问两个基因的功能， 必需的和以前未表征的基因，ii）定义了两个调节子，这两个调节子对于调节细胞分裂至关重要 在结核分枝杆菌中，和iii）确定这些调节网络在持续结核感染期间的重要性。 这些目标采用Mtb感染的表型相关模型，包括巨噬细胞和小鼠模型 疾病。该提案的成功完成将通过阐明Mtb如何调节细胞来推进该领域 部门，并提供深入了解这些调控途径如何有助于结核分枝杆菌的持久性和生存， vivo.了解结核分枝杆菌复制和持久性的机制可以帮助改善和发展 用于治疗结核病的治疗剂。

PROJECT SUMMARY/ABSTRACT Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis, has infected about one-quarter of the global population and kills over 1 million people every year. Mtb is an exceptionally successful human pathogen largely because the bacteria can adapt to withstand several different stresses in vivo and can enter a state of replicative quiescence where Mtb can persist for months to years. This presents major challenges to treating tuberculosis as many anti-tubercular drugs target bacterial replication and cell wall synthesis. Mtb have a unique mechanism of division where the bacteria grow asymmetrically and produce daughter cells that vary in size, growth rate, and cell wall composition. This contrasts with cell division processes employed by other well-studied bacteria, and Mtb possess distinct cellular machinery and regulatory pathways to coordinate their cell division. Thus, it is critical to understand Mtb’s unique mechanism of replication, how it is regulated, and how it contributes to bacterial pathogenesis. The overall goal of this proposal is to elucidate two novel regulatory networks that control Mtb cell division, and to understand the role this regulation plays during tuberculosis infection when Mtb slow or halt their growth. I hypothesize that the uncharacterized transcription factors WhiA and WhiB2 are essential regulators of cell division in Mtb, and that both proteins are required for maintaining bacterial viability in vivo, even during persistent tuberculosis infection when the bacteria enter a slow or non-replicative state. This proposal seeks to i) utilize novel CRISPR interference technology in Mtb to interrogate the function of two essential and previously uncharacterized genes, ii) define two regulons that are critical for regulating cell division in Mtb, and iii) determine the importance of these regulatory networks during persistent tuberculosis infection. These aims employ phenotypically relevant models of Mtb infection, including macrophage and mouse models of disease. Successful completion of this proposal will advance the field by elucidating how Mtb regulate cell division and provide insight into how these regulatory pathways contribute to Mtb’s persistence and survival in vivo. Understanding mechanisms of Mtb replication and persistence can aid with improving and developing therapeutics for treating tuberculosis.