Impact of Sterilizing and Non-sterilizing Antibiotics on M. tuberculosis rRNA Synthesis

灭菌和非灭菌抗生素对结核分枝杆菌 rRNA 合成的影响

• 批准号: 10515341
• 负责人: Nicholas D Walter
• 金额: --
• 依托单位: VA EASTERN COLORADO HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-10-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10515341
• 关键词: Affect; Afghanistan; Antibiotics; Area; Bacteria; Bacterial Infections; Biological Assay; Biological Markers; Cause of Death; Characteristics; Chronic; Conflict (Psychology); Country; Coupled; Development; Drug resistance; Encapsulated; Ethambutol; Granuloma; Health; Human; Human Pathology; Hypoxia; Incidence; Infection; Infiltration; Iraq; Length; Lesion; Linezolid; Lung; Lymphocyte; Measures; Methods; Military Personnel; Minority; Modeling; Monitor; Mus; Mycobacterium tuberculosis; Necrosis; Nutrient availability; Oxygen; Patient Care; Patients; Pharmaceutical Preparations; Pharmacotherapy; Phase; Physiological; Population; Predisposition; Process; Public Health; Pyrazinamide; Regimen; Relapse; Ribosomal RNA; Rifampin; Risk; Services; Surrogate Markers; Testing; Time; Tissues; Treatment Effectiveness; Tuberculosis; Veterans; Work; bactericide; clinical biomarkers; drug development; effectiveness evaluation; improved; isoniazid; lens; novel; novel strategies; pre-clinical; programs; relapse prevention; response; service member; standard care; transmission process; treatment duration; tuberculosis drugs; tuberculosis treatment

Tuberculosis (TB) is an important health concern for veterans and service members who serve in TB-endemic countries. There is an urgent need for new shorter TB treatment. The length of treatment required to prevent relapse is determined by the effectiveness of drugs during the long “sterilizing” phase of treatment that follows early bactericidal killing. Different tissue micro-environments harbor M. tuberculosis (Mtb) populations with different replication rates that respond differently to drug treatment. For example, drugs are more effective against M. tuberculosis (Mtb) in airway and aerated cellular lung infiltrates than in the caseous hypoxic core of necrotic granulomas. We have pioneered a suite of novel assays that will enable us to probe fundamental characteristics of Mtb physiologic state in tissues for the first time. These assays provide an unprecedented lens with which to re-examine historical assumptions about the influence of tissue micro-environment on drug response. These novel assays also enable us to test a novel alternative paradigm for drugs' treatment shortening (sterilizing) activity. Specifically, our novel construct is that reduction in Mtb burden during the sterilizing phase is the combined result of two distinct processes: (1) killing and (2) inhibition of replication. The first process – killing – has long been the primary focus of TB drug development. We hypothesize that the second process – abrogation of Mtb replication – is an important but previously unrecognized contributor to drug sterilizing activity. We believe that drug inhibition of replication in the sterilizing phase of treatment shortens the time needed for durable, non-relapsing cure. We will test this in the C3HeB/FeJ (Kramnik) mouse, a strain that develops well- encapsulated necrotic granulomas with low internal oxygen tension. This model enables us to study Mtb in a spectrum of micro-environments that mimic the pathology of human TB. We will measure Mtb rRNA synthesis at three points (baseline, bactericidal and sterilizing phases) in: (1) airway, (2) cellular lesions, (3) lymphocytic outer cuff of granulomas and (4) hypoxic caseum of necrotic granulomas. Using several complementary methods to quantify Mtb burden, we will determine specifically where Mtb is cleared and where Mtb persists. To test our hypothesis that inhibition of replication contributes to treatment shortening, we will compare regimens with different sterilizing potency: standard treatment (isoniazid, rifampin, pyrazinamide, ethambutol [HRZE]) and a novel regimen that cures TB substantially faster (bedaquiline, pretomanid, linezolid, pyrazinamide [BPaLZ]). Aim 1 will test the association between tissue micro-environmental conditions and Mtb replication before treatment. We hypothesize a spectrum of Mtb rRNA synthesis and replication, ranging from fastest in airway, intermediate in cellular lesions and lymphocytic cuff to slowest in the caseum. Aim 2 will test the association between Mtb replication and drug killing during the bactericidal phase. We hypothesize that drugs will preferentially kill Mtb in micro-environments where Mtb is replicating rapidly (i.e., airway, lymphocytic cuff and cellular lesions). There will be minimal killing of Mtb in caseum during the bactericidal phase. Aim 3 will evaluate the sterilizing phase. Aim 3 will test our hypothesis that a highly potent sterilizing regimen (BPaLZ) will both clear Mtb more effectively and suppress Mtb rRNA synthesis and replication more profoundly than the standard regimen (HRZE). This work will contribute to development of a practical biomarker of sterilizing activity. A marker of sterilizing activity will lead to shorter treatment by improving preclinical drug assessment and improving the accuracy and efficiency of drug trials. Ultimately, this program will also lead to a clinical biomarker for routine monitoring to guide duration of treatment among veterans treated for TB. Our approach could be further extended to many other chronic bacterial infections that are important for veterans.

结核病（TB）是一个重要的健康问题，退伍军人和服务人员谁在结核病流行 国家迫切需要新的较短的结核病治疗。治疗所需的时间，以防止 复发取决于随后漫长的“消毒”治疗阶段中药物的有效性 早期杀菌。不同的组织微环境是M.结核病（Mtb）人群 不同的复制率对药物治疗的反应不同。比如药物更有效 分支杆菌肺组织中的结核杆菌（Mtb）在气道和充气细胞肺浸润中比在干酪样低氧核心中更明显。 坏死性肉芽肿我们开创了一套新的测定方法，使我们能够探测基本的 首次揭示了结核分枝杆菌在组织中的生理状态特征。这些分析提供了前所未有的透镜 重新审视组织微环境对药物影响的历史假设 反应这些新的分析方法也使我们能够测试一种新的替代范式，用于缩短药物治疗时间 （消毒）活动。具体来说，我们的新结构是在灭菌阶段减少结核分枝杆菌负担， 是两个不同过程的综合结果：（1）杀死和（2）抑制复制。第一个过程- 长期以来一直是结核病药物开发的主要焦点。我们假设第二个过程- Mtb复制的消除-是药物灭菌活性的重要但以前未被认识的贡献者。 我们认为，在治疗的绝育阶段药物抑制复制缩短了治疗所需的时间。 持久不复发的治愈方法我们将在C3 HeB/FeJ（Kramnik）小鼠中测试这一点，这是一种发育良好的品系- 具有低内部氧张力的包裹性坏死肉芽肿。这个模型使我们能够在一个 一系列模拟人类结核病病理的微环境。我们将测量结核分枝杆菌rRNA的合成 在三个点（基线、杀菌和消毒阶段）：（1）气道，（2）细胞病变，（3）淋巴细胞 肉芽肿外环;（4）坏死性肉芽肿的缺氧性干酪样变。使用几种互补的方法 为了量化结核病负担，我们将具体确定结核病在哪些地方得到清除，在哪些地方结核病仍然存在。来测试我们 假设抑制复制有助于缩短治疗时间，我们将比较方案与 不同的灭菌效力：标准处理（异烟肼、利福平、吡嗪酰胺、乙胺丁醇[HRZE]）和 一种新的治疗方案，治疗结核病的速度大大加快（贝达喹啉、pretomanid、利奈唑胺、吡嗪酰胺[BPaLZ]）。目的 1将测试治疗前组织微环境条件与Mtb复制之间的关联。 我们假设Mtb rRNA合成和复制的范围从气道中最快， 在细胞病变和淋巴细胞袖口最慢的病例。目标2将检验结核分枝杆菌与 在杀菌阶段的复制和药物杀伤。我们假设药物会优先杀死结核分枝杆菌， Mtb快速复制的微环境（即，气道、淋巴细胞套囊和细胞病变）。那里 将是在杀菌阶段期间对干酪中的Mtb的最小杀死。目标3将评价灭菌阶段。 目标3将检验我们的假设，即高效灭菌方案（BPaLZ）将更有效地清除结核分枝杆菌 并且比标准方案（HRZE）更深刻地抑制Mtb rRNA合成和复制。这项工作 将有助于开发实用的灭菌活性生物标志物。灭菌活性的标记物将 通过改善临床前药物评估和提高治疗的准确性和效率， 药物试验最终，该计划还将导致常规监测的临床生物标志物，以指导持续时间 治疗退伍军人结核病。我们的方法可以进一步扩展到许多其他慢性疾病， 细菌感染对退伍军人很重要。