LATENCY AND REACTIVATION TUBERCULOSIS

描述（由申请人提供）： 结核分枝杆菌感染人类的能力是显著的 宿主并保持静止多年，只有当宿主防御 都被压制了全球三分之一的人口潜伏感染 结核病，但这种临床上不活跃的状态时，杆菌往往是非- 可培养的是知之甚少和不充分的特点。适当 需要更准确地模拟人类疾病的动物模型来测试 疫苗候选人，并了解之间的复杂关系 分枝杆菌和宿主。目前可用的小鼠动物模型和 豚鼠的特征是多菌性疾病， 由主机响应。小鼠的迟发型超敏反应较差 并发展成慢性肺病，最终死于 肉芽肿性肺病，细菌负荷高。豚鼠也 患有多菌性疾病，但对快速 血行播散和强烈的DTH反应， 肺部炎症、破坏和死亡。少杆菌潜伏性疾病可 只能通过使用抗生素来诱导。相反，兔子 对M.结核病与A型山 肉芽肿反应，有效地包含杆菌。过程中 6- 12个月，所有可培养杆菌消失。此外该 组织病理学反应与人类非常相似， 兔结核病模型作为一种有前途的研究途径 宿主和杆菌的阶段特异性变化。 在这个应用中，我们将气溶胶感染兔子， 肉芽肿性肺部病变消退至潜伏期。与使用 免疫抑制剂，如皮质类固醇、iNOS抑制剂，和 特异性抗细胞因子抗体，我们将重新激活感染。同时，我们 将使用兔白色血细胞改进体外肉芽肿测定， 我有一个体外模型，可以与我们的体内模型相关联和比较， 结果在感染的不同阶段收集血清和兔组织， 将表征阶段特异性宿主体液和细胞介导的免疫 应答了解潜伏性疾病期间的抗体表达谱 可能会导致重要的诊断，在疾病的诊断阻碍， 敏感性和特异性低。此外，我们将分析 使用微阵列的细菌对不同疾病阶段的转录应答 和分子信标RT-PCR。最后，我们将使用转座子突变体 文库以鉴定在感染的特定阶段受损的克隆。 合适的动物模型对于成功开发 结核病疫苗、新药和更好的结核病诊断测试。

DESCRIPTION (provided by applicant): Mycobacterium tuberculosis is remarkable in its ability to infect the human host and remain quiescent for many years only to reactivate when host defenses are suppressed. One-third of the global population is latently infected with tuberculosis, yet this clinically inactive state when bacilli are often non- cultivatable is poorly understood and inadequately characterized. Appropriate animal models that more accurately mimic human diseases are needed to test vaccine candidates, and to understand the complex relationship between mycobacteria and host. The currently available animal models in mice and guinea pigs are characterized by multibacillary disease and are distinguished by the host response. Mice mount a poor delayed type hypersensitivity response and develop chronic lung disease, eventually succumbing to a progressive granulomatous pulmonary disease with high bacillary load. Guinea pigs also have a multibacillary disease, but are exquisitely susceptible with rapid hematogenous dissemination and a strong DTH response that results in rapid lung inflammation, destruction and death. Paucibacillary latent disease can only be induced with the administration of antibiotics. In contrast, rabbits are relatively resistant to aerosol infection with M. tuberculosis and mount a granulomatous response that effectively contains the bacilli. Over the course of 6-l2 months, all culturable bacilli disappear. In addition, the histopathologic response is remarkably similar to that of humans pointing to the rabbit model of tuberculosis as a promising avenue by which to study stage-specific changes in both host and bacilli. In this application, we will aerosol infect rabbits and allow the granulomatous lung lesions to regress to latency. With the use of immunosuppressive agents such as corticosteroids, iNOS inhibitors, and specific anti-cytokine antibody, we will reactivate infection. In parallel, we will refine the in vitro granuloma assay using rabbit white blood cells to have an in vitro model with which to correlate and compare our in vivo results. Harvesting serum and rabbit tissue at various stages of infection, we will characterize the stage-specific host humoral and cell-mediated immune responses. Understanding the antibody expression profile during latent disease may lead to important diagnostics in a disease hampered by diagnostics with low sensitivity and specificity. In addition, we will analyze the transcriptional bacterial response to various disease stages using microarrays and RT-PCR with molecular beacons. Finally, we will use a transposon mutant library to identify clones that are impaired in specific stages of infection. Appropriate animal models are critical to the successful development of tuberculosis vaccines, new drugs and better diagnostic tests for tuberculosis.