Discovery of marine natural products targeting latent M. tuberculosis

发现针对潜伏结核分枝杆菌的海洋天然产物

• 批准号: 8620608
• 负责人: Kyle H Rohde
• 金额: $ 18.06万
• 依托单位: UNIVERSITY OF CENTRAL FLORIDA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2015-03-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8620608
• 关键词: Address; Alveolar Macrophages; Anti-Bacterial Agents; Antibiotic Therapy; Antibiotics; Bacillus (bacterium); Bacteria; Biological Assay; Cells; Chemicals; Clinical Treatment; Collaborations; Development; Disease; Drug Resistant Tuberculosis; Drug Targeting; Drug resistance; Drug resistance in tuberculosis; Environment; Exhibits; Funding; Genus Mycobacterium; Goals; Granuloma; Growth; Hypoxia; In Vitro; Infection; Institutes; Lead; Lesion; Libraries; Liquid substance; Metabolic; Methods; Modeling; Multi-Drug Resistance; Mycobacterium tuberculosis; Nutrient; Pathway interactions; Patients; Pharmaceutical Preparations; Phase; Physiological; Population; Procedures; Public Health; Refractory; Regimen; Source; Specificity; Starvation; Stress; Structure; Treatment Failure; Treatment Protocols; Tuberculosis; United States National Institutes of Health; bactericide; cytotoxicity; global health; high throughput screening; improved; in vitro Model; in vivo; killings; macrophage; marine natural product; marine organism; meetings; novel; pathogen; public health relevance; pulmonary granuloma; resistant strain; screening; tuberculosis drugs; tuberculosis treatment

DESCRIPTION (provided by applicant): 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, ther 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 whic 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.

结核病是由结核分枝杆菌（Mtb）引起的毁灭性全球健康危机，每年夺去200多万人的生命。这种病原体能够在巨噬细胞内存活，并在患者体内持续多年，导致潜伏性结核感染（LTBI）。结核分枝杆菌对抗生素治疗是难治的，因为潜伏的（或休眠的）TB由于对肺肉芽肿病变内的条件的代谢和结构适应而表现出表型耐药性。因此，成功治疗结核病需要一种方案，包括6-9个月的多种药物的鸡尾酒疗法。耐多药结核分枝杆菌菌株的出现使本已困难的结核病治疗任务进一步复杂化。因此，迫切需要具有能够缩短治疗过程并杀死耐药性和潜伏性Mtb的新型作用模式的强效药物。该提案旨在解决有效杀死潜伏Mtb的药物严重缺乏的问题。在港口分支海洋研究所（HBOI）的合作，我们将利用巨大的化学多样性存在于海洋生物的次级代谢产物中，通过筛选海洋天然产物（MNP）的峰值库对结核分枝杆菌在两个模型的潜伏期。在R21阶段，我们将在初步研究的基础上，使用体外多重应激模型（MSM）的潜伏期（目标1），筛选约5000 MNP在对数期肉汤培养物中、巨噬细胞中生长的Mtb和休眠Mtb的抗Mtb活性。此外，我们将纯化和结构表征我们在完成的中试筛选中鉴定的对Mtb杀菌的“命中”级分（Aim 2）。在R33阶段，我们将从所有三个筛选的命中馏分中纯化并确定优先活性化合物的结构（目标3），最后，我们将对纯化的先导化合物进行详细表征，以确定其效力，特异性和潜在靶标和作用模式（目标4）。我们假设，这些模型将有利于识别对潜伏性结核分枝杆菌有活性的药物，这些药物靶向体内生存条件必需的途径。我们预计，MNP中存在的化学多样性将有助于识别具有独特结构，目标和作用机制的化合物。我们的长期目标是发现新的先导化合物，这将显着改善治疗潜伏和耐药结核病。