Validation of RelA as a Target for Mycobacterium Tuberculosis Persisters

验证 RelA 作为结核分枝杆菌持续存在的靶标

基本信息

批准号：
9086238
负责人：
Petros C Karakousis
金额：
$ 24.3万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-06-15 至 2018-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9086238
关键词：
Adherence Animal Model Antibiotics Antitubercular Agents Bacillus (bacterium)Bacteria Biological Assay C3HeB/FeJ Mouse Cells Chronic Phase Data Defect Development Disease Dose Drug Interactions Drug resistance Enzymes Evaluation Exhibits Extreme drug resistant tuberculosis Genes Goals Granuloma Growth Guanosine HIV Health Histologic Human Immune In Vitro Infection Knowledge Lead Libraries Lung Medical Microbiology Molecular Biology Molecular Genetics Multi-Drug Resistance Mus Mycobacterium tuberculosis Necrosis Nutrient Patients Persons Pharmaceutical Preparations Play Predisposition Recombinants Regimen Role Solubility Starvation Stress Structure-Activity Relationship Temperature Testing Time Toxic effect Tuberculosis Validation Work bactericide base chemotherapy clinically relevant co-infection cytotoxicity drug development effective therapy exhaust experience extensive drug resistance improved in vitro Assay in vitro activity in vivo inhibitor/antagonist isoniazid killings mutant overexpression prevent pulmonary granuloma reconstitution relapse risk response scaffold small molecule inhibitor stability testing standard care treatment duration tuberculosis drugs tuberculosis treatment

项目摘要

DESCRIPTION (provided by applicant): The lengthy and complicated multidrug therapy currently available to treat active tuberculosis (TB) infection has contributed to medical non-adherence and the emerging problems of multidrug-resistant (MDR)- and extensively drug-resistant (XDR)-TB, which are particularly deadly in the setting of HIV co-infection. In addition, persons with HIV are at increased risk for relapse even upon successful completion of anti-TB treatment. The prolonged therapy required to eradicate TB infection is believed to reflect the ability of Mycobacterium tuberculosis (Mtb) to persist within host necrotic granulomas in a non-replicating state characterized by antibiotic tolerance to bactericidal drugs, which predominantly target actively dividing tubercle bacilli. Hyperphosphorylated guanosine ((p)ppGpp), which is synthesized by the stringent response enzyme RelA, plays an important role in bacterial growth restriction and antibiotic tolerance. RelA is essential for long-term Mtb survival during various i vitro and in vivo growth-limiting conditions. Recently, we found that relA-deficient Mtb exhibits enhanced susceptibility to isoniazid during nutrient starvation and in the lungs of chronically infected mice. Our collaborators at GlaxoSmithKline's Tres Cantos Open Lab for Diseases of the Developing World (GSK-DDW) have screened a library of over 2 million compounds in RelA-inhibition assays and whole- cell screens. Of 178 hits representing 18 unique scaffolds, we have found 8 of 12 scaffolds tested to have potent, RelA-specific activity against nutrient-starved Mtb. The goal of this proposal is to validate RelA as a target for Mtb persisters in vivo and develop RelA inhibitors for targeting persistent bacilli, with the ultimate goal of identifyinga lead compound, which can shorten the duration of treatment for TB by "awakening" persisters and rendering them more susceptible to killing by standard anti-TB drugs. Specifically, we will screen hits using various in vitro assays to select candidates, which will be used for preliminary toxicity studies and to validate the target in vivo. In addition to improving medical adherence and reducing the potential for the development of drug resistance, an abbreviated drug regimen to treat active TB would be particularly useful in HIV co-infected patients, since drug-drug interactions and immune reconstitution may complicate the concurrent management of both infections.

描述（由申请人提供）：目前用于治疗活动性结核病（TB）感染的漫长而复杂的多药治疗导致了医疗不依从性以及新出现的多重耐药（MDR）和广泛耐药（XDR）问题-结核病，在艾滋病毒合并感染的情况下尤其致命。此外，即使成功完成抗结核治疗，艾滋病毒感染者的复发风险也会增加。根除结核感染所需的长期治疗被认为反映了结核分枝杆菌 (Mtb) 在宿主坏死肉芽肿中以非复制状态持续存在的能力，其特征是对杀菌药物的抗生素耐受性，主要针对活跃分裂的结核杆菌。高度磷酸化鸟苷 ((p)ppGpp) 由严格响应酶 RelA 合成，在细菌生长限制和抗生素耐受性中发挥重要作用。 RelA 对于 Mtb 在各种体外和体内生长限制条件下的长期存活至关重要。最近，我们发现relA缺陷的Mtb在营养饥饿期间和慢性感染小鼠的肺部表现出对异烟肼的敏感性增强。我们在葛兰素史克 Tres Cantos 发展中国家疾病开放实验室 (GSK-DDW) 的合作者通过 RelA 抑制测定和全细胞筛选筛选了超过 200 万种化合物的库。在代表 18 个独特支架的 178 个命中中，我们发现 12 个支架中的 8 个经过测试，对营养匮乏的结核分枝杆菌具有有效的 RelA 特异性活性。该提案的目标是验证 RelA 作为 Mtb 持续存在者体内的靶标，并开发针对持续性杆菌的 RelA 抑制剂，最终目标是确定一种先导化合物，该化合物可以通过“唤醒”持续者和缩短结核病治疗持续时间。使他们更容易被标准抗结核药物杀死。具体来说，我们将使用各种体外测定筛选命中以选择候选物，这些候选物将用于初步毒性研究并在体内验证目标。除了提高医疗依从性和减少产生耐药性的可能性之外，治疗活动性结核病的简化药物治疗方案对于艾滋病毒合并感染的患者特别有用，因为药物间相互作用和免疫重建可能使同时治疗结核病的同时管理变得复杂。两种感染。