Replisome dynamics in M tuberculosis_linking persistence to genetic resistance

 描述（由申请人提供）：结核病（TB）药物发现计划的一个主要目标是开发将缩短治疗持续时间的化合物，同时限制病原体结核分枝杆菌（Mtb）耐药菌株的出现。目前的六个月方案被认为是由于现有的抗结核药无法消除一个亚群的结核杆菌是顽固的杀死，尽管保留了完整的遗传易感性的应用药物。结核分枝杆菌“持久性”的存在，以及耐药临床分离株的日益出现，反过来又提出了一个关键问题：（非遗传）持久性和遗传耐药性的发展之间是否存在功能性联系？在这里，我们将测试的假设，即通过控制功能参与DNA修复和损伤耐受性，分枝杆菌SOS反应中起着关键作用的固有异质性的结核分枝杆菌种群，因此，有助于结核分枝杆菌的能力，坚持面对致命的压力，包括药物治疗。我们还将评估这样的概念，即SOS调节的imuA '-imuB/dnaE 2“突变体”，这是以前在体内的Mtb生存和耐药性，驱动诱变暴露于杀虫剂的持久性群体，因此链接持久性和遗传抗性。最后，我们将利用生物化学和基于靶点的全细胞（TB-WCS）筛选，以确定新的化学抑制剂，使结核分枝杆菌对遗传毒性应激敏感，并消除体外药物选择性压力下出现的耐药性。这一完全合作的提案将利用生物化学、遗传学和微生物学技术，需要双方合作伙伴共同开发和应用。此外，它是基于科学见解和技术专长的公开转让，作为新合作的一部分，旨在围绕分枝杆菌DNA复制和修复的基本方面的调查建立长期伙伴关系，作为新型抗结核药物的未充分探索的目标。

 DESCRIPTION (provided by applicant): A major goal of tuberculosis (TB) drug discovery programs is the development of compounds that will reduce the duration of therapy, simultaneously limiting the emergence of drug-resistant strains of the causative agent, Mycobacterium tuberculosis (Mtb). The current six-month regimen is thought to result from the inability of existing anti-tuberculars to eliminate a sub-population of Mtb bacilli that are refracory to killing despite retaining full genetic susceptibility to the applied drugs. The existence of thee Mtb "persisters", together with the increasing emergence of drug-resistant clinical isolates, in turn raises a critical question: is there a functional link between (non-genetic) persistence and the development of genetic drug resistance? Here, we will test the hypothesis that, by controlling functions involved in DNA repair and damage tolerance, the mycobacterial SOS response plays a key role in the inherent heterogeneity of Mtb populations and, therefore, contributes to the ability of Mtb to persist in the face of lethal stresses including drug treatmen. We will also evaluate the notion that the SOS-regulated imuA'-imuB/dnaE2 "mutasome", which was previously implicated in Mtb survival and drug-resistance in vivo, drives mutagenesis in antibiotic-exposed persister populations and so links persistence and genetic resistance. Finally, we will utilize biochemical and target-based whole-cell (TB-WCS) screens to identify novel chemical inhibitors which sensitize Mtb to genotoxic stress and eliminate the emergence of resistance under drug-selective pressure in vitro. This fully collaborative proposal will utilize biochemical, genetic, and microbiological techniques that will require both partners to develop and apply. Moreover, it is predicated on the open transfer of scientific insight and technical expertise as part of a new collaboration designed to create a long-term partnership around the investigation of fundamental aspects of mycobacterial DNA replication and repair as an underexplored target for novel anti-TB agents.