A "radical" approach to tuberculosis infection

Abstact.结核病仍然是一种发病率和死亡率很高的疾病。使其 管理是其多种表现，从急性疾病到潜伏感染。据估计 世界上1/3的人口患有潜伏性结核病，这导致了一个巨大的水库， 疾病可以发生。迫切需要更有效的药物来简化和缩短疗程， 以应对遵守绝育和治愈所需的必要的漫长课程的挑战。 在活动性和潜伏性感染期间，已经提出细菌的群体或亚群体 进入可逆的非复制状态，传统抗生素难以治疗。术语表型抗生素 耐药性（药物耐受性）用于描述抗生素对这些细菌的疗效降低， 缺乏基因型抗性。在结核分枝杆菌中，已经提出体内药物耐受性可以解释结核分枝杆菌的耐药性。 在长期治疗的情况下感染的持续存在。因此，结合我们对药物耐受性的理解 细菌在化疗中存活的基础可能是治疗发现的关键， 设计针对潜伏和持续感染的新策略。 近年来，植物诱导的活性氧（ROS）已被认为是一种重要的生物学机制。 在敏感细胞中抗生素功效中起重要作用，而保护免受ROS的机制起作用 在药物耐受性方面。事实上，这种保护机制已经涉及所有目前的体外模型， 耐药性因此，抑制或压倒允许耐药细菌存活的机制， ROS的细胞应激是一种创新的、有前途的策略，可快速杀灭潜伏或持续感染 在这个项目中，我们建议开发新的检测方法来鉴定小分子候选物， 能够通过破坏耐药结核分枝杆菌的解毒能力来杀灭耐药结核分枝杆菌， ROS，或增加细菌中ROS的产生从而导致其死亡。我们将使用一种药物模型 利用硫脲淬灭抗生素暴露产生的羟基自由基的能力的耐受性， 从而诱导药物耐受性。然后，我们将筛选两个独特的，有价值的小分子集合： 我们已经鉴定了676种分子的集合，这些分子对营养缺乏的结核分枝杆菌具有活性 它们对目前可用的结核病药物具有耐药性， 这是布罗德研究所创建的一个合成分子库。将培养有前途的候选人 获得用于在慢性和潜伏性结核病小鼠模型中进行测试的分子。这部作品将把小说 靶向ROS介导的机制的生物学概念， 化学在DOS图书馆收藏，并将借鉴药物发现的专业知识，从领导人在 制药行业现在在布罗德研究所和结核病候选药物体内测试的专业知识， 约翰霍普金斯。

Abstact. Tuberculosis continues to be a disease of significant morbidity and mortality. Complicating its management are its diverse manifestations, ranging from acute disease to latent infection. It is estimated that 1/3 of the world's population has latent TB, resulting in an enormous reservoir from which reactivation to acute disease can occur. More effective drugs are urgently needed to simplify and shorten treatment courses in order to address the challenges of compliance to the requisite lengthy courses required for sterilization and cure. During both active and latent infection, it has been proposed that a population or subpopulation of bacteria enters a reversible non-replicating state, refractory to traditional antibiotics. The term phenotypic antibiotic tolerance (drug tolerance) is used to describe the reduced efficacy of antibiotics against these bacteria in the absence of genotypic resistance. In Mtb, it has been proposed that in vivo drug tolerance could explain the persistence of infection in the face of prolonged therapy. Thus, integrating our understanding of drug tolerance and the basis for bacterial survival in the face of chemotherapy into therapeutic discovery could be key to designing new strategies for targeting latent and persistent infection. Recently, antibiotic-induced reactive oxygen species (ROS) have been recognized as playing an important role in antibiotic efficacy in susceptible cells while mechanisms that protect against ROS play a role in drug tolerance. In fact, such protective mechanisms have been implicated in all current in vitro models of drug tolerance. Thus, inhibiting or overwhelming the mechanisms that allow drug-tolerant bacteria to survive the cellular stress of ROS is an innovative, promising strategy to rapidly sterilize latent or persistent infection In this project, we propose to develop novel assays to identify small molecule candidates which are able to sterilize drug tolerant Mtb bacilli by disrupting their ability to detoxify and thus survive the stress of ROS, or that increase ROS production in bacilli thus contributing to their death. We will use a model of drug tolerance that exploits the ability of thiourea to quench hydroxyl radicals generated by antibiotic exposure, thereby inducing drug tolerance. We will then screen two unique, valuable collections of small molecules: a collection of 676 molecules that we have already identified as having activity against nutrient starved Mtb which are otherwise drug tolerant to currently available TB drugs, and a unique 100,000 diversity oriented synthetic molecule library that has been created at the Broad Institute. Promising candidates will be developed to obtain molecules for testing in chronic and latent mouse models of TB. This work will integrate the novel biological concept of targeting ROS-mediated mechanisms for targeting persistence and latency with novel chemistry in the DOS library collection, and will draw upon drug discovery expertise from leaders in the pharmaceutical industry now at the Broad Institute and expertise in in vivo testing of TB drug candidates at Johns Hopkins.