Discovery of marine natural products targeting latent M. tuberculosis

项目摘要 -- 结核病是由结核分枝杆菌(Mtb)引起的毁灭性的全球健康危机 每年夺走200多万人的生命。这种病原体能够在巨噬细胞内存活并持续存在。 多年来在患者体内，导致潜伏的结核病感染(LTBI)。结核分枝杆菌对抗生素治疗耐药 因为潜伏期(或潜伏期)结核病由于代谢和结构性的原因而表现出表型耐药性 对肺肉芽肿病变内条件的适应。因此，结核病的成功治疗 需要一种包括多种药物鸡尾酒的养生法，服用时间为6-9个月。新技术的出现 耐多药结核分枝杆菌菌株使本已困难的结核病治疗任务进一步复杂化。因此， 迫切需要有效的药物，具有新的作用模式，能够缩短病程 治疗和杀死耐药和潜伏的结核分枝杆菌。这项提议旨在解决这一严重缺乏 有效杀死潜伏的结核杆菌的药物。与海港分会海洋研究所(HBOI)合作， 我们将利用海洋次生代谢物之间存在的巨大化学多样性。 通过在两个模型中筛选抗结核分枝杆菌的海洋天然产物(MNP)的峰值文库 延迟。在R21阶段，我们将在初步研究的基础上，筛选~5000个MNP的活性 在对数阶段肉汤培养中抗结核分枝杆菌，在巨噬细胞中生长的结核分枝杆菌，以及使用体外 潜伏期多应激模型(目标1)。此外，我们还将提纯和结构化地描述“Hit” 我们在完成的中试筛选中确定的对结核分枝杆菌具有杀菌作用的级分(目标2)。在R33阶段， 我们将从这三种化合物中提纯并定义优先活性化合物的结构 筛选(目标3)，最后，我们将对纯化的铅化合物进行详细的表征，以 确定其效力、特异性、潜在目标和行动模式(目标4)。我们假设 这些模型将有利于识别针对潜伏的结核分枝杆菌靶向通路的活性药物 对在体内存活是有条件的必要的。我们预计，MNP中存在的化学多样性将 促进具有独特结构、靶点和作用机制的化合物的鉴定。我们的 长期目标是发现新的先导化合物，从而显著改善癌症的治疗 潜伏性和抗药性肺结核。

Project Summary   Tuberculosis is a devastating global health crisis caused by Mycobacterium tuberculosis (Mtb) that claims over 2 million lives each year. This pathogen is able to survive inside macrophages and persist within patients for years, causing latent TB infections (LTBI). Mtb is refractory to antibiotic treatment because latent (or dormant) TB exhibit phenotypic drug resistance due to metabolic and structural adaptations to conditions within pulmonary granuloma lesions. As a result, successful treatment of TB requires a regimen including a cocktail of multiple drugs administered for 6-9 months. The emergence of multi-drug resistant Mtb strains has further complicated the already difficult task of treating TB. Thus, there is a dire need for potent drugs with novel modes of action capable of shortening the course of treatment and killing drug-resistant and latent Mtb. This proposal seeks to address this critical lack of drugs that effectively kill latent Mtb. In collaboration with Harbor Branch Oceanographic Institute (HBOI), we will exploit the enormous chemical diversity present among secondary metabolites of marine organisms by screening a peak library of marine natural products (MNP) against Mtb in two models of latency. In the R21 phase, we will build upon preliminary studies by screening ~5000 MNP for activity against Mtb in log-phase broth cultures, Mtb growing in macrophages, and dormant Mtb using an in vitro multi-stress model (MSM) of latency (Aim 1). In addition, we will purify and structurally characterize “hit” fractions bactericidal for Mtb which we identified in a completed pilot screen (Aim 2). In the R33 phase, we will purify and define the structures of prioritized active compounds from hit fractions from all three screens (Aim 3), Finally, we will conduct detailed characterization of purified lead compounds to determine their potency, specificity, and potential targets and mode of action (Aim 4). We hypothesize that these models will favor the identification of drugs active against latent Mtb that target pathways conditionally essential for survival in vivo. We anticipate that the chemical diversity present in MNP will facilitate the identification of compounds with unique structures, targets, and mechanisms of action. Our long-term goal is the discovery of novel lead compounds that would significantly improve the treatment of latent and drug-resistant tuberculosis.