Metabolic determinants of barrier function in rifampin-sensitive and -resistant Mtb

项目2 -利福平敏感和耐药结核分枝杆菌屏障功能的代谢决定因素 项目负责人：Kyu Rhee 合作研究者：Valerie Mizrahi 合作研究者：Jeremy Rock（核心D），D.分支穆迪（核心B） 摘要 这个项目的首要目标是阐明特定的细胞被膜结构与活性的关系 介导屏障功能。更安全、更简单的结核病药物和治疗方法的一个关键和相当实际的障碍是， 非常不寻常的细胞膜因此，Mtb包络的势垒函数的改进知识表示 开发更好更安全药物的潜在蓝图。与大多数细菌不同，结核分枝杆菌（Mtb） 包膜是一种独特的多层结构，其物理化学性质被广泛认为 介导抗生素耐药性的内在机制。使用新开发的全生物化学品 分析和基因组规模的CRISPRi技术，我们挑战了长期以来认为结核分枝杆菌细胞壁是 静态且不渗透化学屏障。初步研究表明，结核分枝杆菌细胞包膜是化学 选择性，并且其阻隔活性不是其本体物理化学性质的简单产物。这些数据 进一步表明其组成和屏障功能都是动态调节的。该项目具体 通过一线结核病药物利福平的治疗透镜关注结核病屏障功能。我们专注于 利福平，因为其独特的治疗缩短和杀菌活性对药物敏感的结核病， 在耐药结核病生物学中的决定性作用。此外，由于利福平具有单一的，众所周知的 作用靶点，RNA聚合酶的B亚单位，位于胞质溶胶中，它作为一个潜在的模型 这可以阐明适用于任何细胞溶质靶向药物的一般原理。

Project 2 - Metabolic determinants of barrier function in rifampin-sensitive and -resistant Mtb Project Leader: Kyu Rhee Co-investigator: Valerie Mizrahi Collaborating investigators: Jeremy Rock (Core D), D. Branch Moody (Core B) ABSTRACT The overarching goal of this project is to elucidate specific cell envelope structure-activity relationships mediating barrier function. A key and quite literal barrier to safer and simpler drugs and treatments for TB is its highly unusual cell envelope. Improved knowledge of the barrier function of the Mtb envelope thus represents a potential blueprint to developing better safer drugs. Unlike most bacteria, the Mycobacterium tuberculosis (Mtb) envelope consists in a unique multilayered structure whose physico-chemical properties are widely believed to mediate an intrinsic mechanism of antibiotic resistance. Using newly developed whole organism chemical profiling and genome scale CRISPRi technologies, we challenge the longstanding view of Mtb cell wall as a static and impermeant chemical barrier. Preliminary studies indicate that the Mtb cell envelope is chemically selective, and its barrier activity is not a simple product of its bulk physico-chemical properties. These data further show that both its composition and barrier function are dynamically regulated. This project specifically focuses on Mtb barrier function through the therapeutic lens of the frontline TB drug rifampicin. We focus on rifampicin because of its unique treatment shortening and sterilizing activities against drug-sensitive TB, and its defining role in the biology of drug-resistant TB. In addition, because rifampicin has a single, well understood target of action, the b subunit of RNA polymerase, which is located in the cytosol, it serves as a potential model that could elucidate general principles that apply to any drug with cytosolic targets.