Development of a mouse model of tuberculosis that generates human-like pathology

摘要尽管在过去的40年里，几乎没有新的结核病药物问世。 多年来，与结核病治疗发展相关的关键问题在整个领域都得到了很好的阐述，并 正在生物医学界以极大的活力进行着研究。我们能找到一个缩短治疗时间的方法吗？ 从现在的六个月开始？哪些新的作用机制将支持完全绝育 与现有的护理治疗标准相结合？是不是通过一种 具体治疗方案是什么？ 为了在临床上取得成功，我们首先必须在临床前通过使用 可预测的动物模型。评价实验性结核病疗法的疗效是很常见的。 由于小鼠的体积相对较小，成本较低，因此使用小鼠模型进行实验。然而，许多鼠标 模型不能重现类似人类的病理，特别是缺氧性坏死性肉芽肿，以及 因此对某些化合物的预测价值可能有限。小鼠模型确实发展成与人类相似的模型 病理学可能会受到严重异质性或复杂方案的影响，以限制显著的发病率。 我们最近的工作克服了这些显著的限制，在这里，我们建议改进、验证和 描述一种创新的结核病小鼠模型，它更能预测患者的结果。 我们已经在老鼠身上完成了一系列研究，这些研究增强了我们推进更具预测性的模型的能力 结核病，一种持续产生类似人类的病理形式的缺氧性坏死性肉芽肿。这 新的模型建立在证明NOS2-/-小鼠发生缺氧性肉芽肿的工作基础上，但增加了 通过简化方案和利用天然气雾剂途径感染小鼠而具有重要价值 结核分枝杆菌部分减毒株R1Rv。我们已把这种新颖的型号与 特异性标记药物和免疫耐受结核分枝杆菌细胞的荧光报告菌株。当一起部署时 为了支持潜在的结核病药物方案的药理学评估，这两个工具可以提供独特的 洞察为什么一些治疗方法可以很好地缩短患者的化疗时间，而 其他人则不会这么做。在这项建议中，我们寻求建立模型的预测价值来确定药物 疗效反应，并揭示耐药结核分枝杆菌生物学的新见解。 在前两个具体目标中，我们试图优化新的鼠标模型，并将其验证为更严格的 体内抗结核药物疗效的测量，在第三个目标中，我们使用该模型来识别生态位 被耐药细胞占据，以更好地了解它们潜在的脆弱性。完成三项工作 这项提案的目的是提供一个更具预测性和更具特征性的结核分枝杆菌小鼠模型 这种感染有可能成为小动物试验结核病药物的新标准。

ABSTRACT Though very few new tuberculosis (TB) drugs have been introduced over the past forty years, the pivotal questions relevant to TB therapeutic development are well articulated across the field and are being pursued with great vigor in the biomedical community. Can we find a way to shorten treatment for from the current six months? Which novel mechanisms of action will support complete sterilization when combined with existing standard of care treatment? Are persister populations completely eliminated through a specific treatment regimen? In order to succeed in the clinic, first we must address these questions preclinically through the use of predictive animal models. Evaluation of the efficacy of experimental tuberculosis therapeutics is commonly performed using mouse models, due to the relatively small size and low cost of mice. However, many mouse models fail to reproducibly develop human-like pathology, specifically hypoxic necrotic granulomas, and thereby may have limited predictive value for certain compounds. Mouse models which do develop human-like pathology may suffer from substantial heterogeneity or complex protocols required to limit significant morbidity. Our recent work has overcome these significant limitations, and here we propose to refine, validate and characterize an innovative mouse model of TB that is more predictive of outcomes in patients. We have completed a series of studies in mice that strengthen our ability to advance a more predictive model of TB, one that consistently produces human-like pathology in the form of hypoxic necrotic granulomas. This new model builds on work that demonstrated the development of hypoxic granulomas in Nos2-/-mice, but adds significant value by simplifying the protocol and utilizing the natural aerosol route to infect mice with the partially attenuated Mycobacterium tuberculosis (Mtb) strain R1Rv. We have paired this novel model with fluorescent reporter strains that specifically mark drug and immune tolerant Mtb cells. When deployed together to support pharmacological evaluation of potential TB drug regimens, these two tools can provide unique insights into why some therapeutic approaches may work well to shorten chemotherapy in patients, while others will not do so. In this proposal, we seek to establish the predictive value of the model to determine drug efficacy responses, and to reveal new insights into the biology of drug-tolerant Mtb. In the first two Specific Aims we seek to optimize the novel mouse model and validate it as a more rigorous measure of in vivo anti-tubercular drug efficacy, and in the third Aim we employ the model to identify the niche occupied by drug tolerant cells, to better understand their potential vulnerabilities. Completion of the three Aims of this proposal will deliver a more predictive and well-characterized mouse model of Mtb infection that will have the potential to become a new standard for small animal testing of TB drugs.