Evaluation of novel TB drug regimens by targeting resuscitation promoting factor-dependent persistent Mycobacterium tuberculosis in the Cornell model

结核病虽然是可以治愈的，但仍然是世界上最大的杀手之一。每年全球有近200万人死于该病。98%的结核病死亡病例发生在发展中国家，主要影响处于多产年龄段的年轻人。25万死于结核病的人也感染了免疫系统减弱的艾滋病毒，这些人中的大多数都在非洲。结核病尤其影响最脆弱的人群，包括儿童、最贫穷的人和营养不良的人。肺结核是由一种叫做结核分枝杆菌的细菌引起的。这种疾病的一个重要特征是，这种细菌具有在人体内长时间生长和存活的不同寻常的能力。因此，据估计，20亿人，相当于世界总人口的三分之一，感染了这种细菌，在这种细菌中，它会引起不明显的潜伏感染，导致5-10%的终身活动性疾病风险。这些持久性细菌不能用标准的微生物方法培养，也不能被目前的结核病药物杀死。因此，结核病的治疗需要较长的时间，需要四种药物才能治愈患者。这种长期治疗非常难以实施，特别是在发展中国家，因为缺乏负担能力以及有限的医疗服务和基础设施。这项拟议的研究旨在识别和量化结核病感染小鼠在治疗前、治疗期间和治疗后的持久性细菌，以预测人类结核病治疗的结果。通过添加复苏促进因子(RPF)，持久性细菌将被“唤醒”，RPF是结核分枝杆菌产生的重新开始生长的蛋白质。我们最近在小鼠身上的研究表明，在目前的治疗药物方案中添加的高剂量利福平或贝达奎兰能够杀死持续的RPF复苏细菌。这意味着治疗时间可以缩短，复发率也会降低。我们还修改了康奈尔模型，通过丰富持久性细菌并确定它们的清除来更好地模拟人类感染。在这项建议中，我们将应用我们在使用一套新的药物方案对小鼠进行研究时学到的相同原理和技术来预测人类结核病治疗的结果，特别是疾病复发。我们将在小鼠身上建立一个模型系统，作为试验台，在将新药方案应用于更昂贵、更耗时的人体试验之前，评估它们的效力。

Tuberculosis, although curable, still remains one of the biggest killers in the world. It kills nearly 2 million people worldwide every year. 98% of tuberculosis deaths are in the developing world affecting mostly young adults in their productive years. A quarter of a million tuberculosis deaths are also infected with HIV with weakened immune systems, most of these people are in Africa. Tuberculosis especially affects the most vulnerable populations including children, the poorest and malnourished. Tuberculosis is caused by the bacterium called Mycobacterium tuberculosis. One important characteristic of this disease is that the bacterium has an unusual ability to grow and survive for extended periods of time in human body. Therefore, it has been estimated that 2 billion people, equal to one-third of the world's total population, are infected with the bacterium in whom it causes unnoticeable latent infections that lead to a 5-10% lifetime risk of active disease. These persistent bacteria cannot be cultured using standard microbiological methods and are not killed by the current tuberculosis drugs. Therefore, tuberculosis treatment needs a long period of time with four drugs to cure the patients. This long-term treatment is extremely difficult to implement especially in developing countries because of lack of affordability and limited healthcare services and infrastructure. The proposed research aims to identify and quantify those persistent bacteria in tuberculosis-infected mice before, during and after treatment to predict the outcome of human tuberculosis treatment. The persistent bacteria will be "woken" by the addition of resuscitation promoting factors (RPF) which are proteins produced by M. tuberculosis to restart growth. We have shown in our recent study in mice that high-dose rifampicin or bedaquiline which was added in the current treatment drug regimen was able to kill persistent RPF resuscitated bacteria. This meant that the treatment duration could be shortened with a reduced relapse rate. We also modify the Cornell model to better mimic human infection by enriching persistent bacteria and determining their clearance. In this proposal, we will apply the same principals and techniques which we have learned from studying mice using a set of novel drug regimens to predict the outcome of human tuberculosis treatment, especially disease relapse. We will establish a model system in mice as a testbed to evaluate the potencies of new drug regimens prior to their application in more expensive and time-consuming human testing.