Validation and Application of a Model for Human-like TB Latency in Rabbits

项目2将在新西兰白色兔中验证类人结核潜伏期模型，并应用该模型 以测试针对潜伏性TB感染（LTBI）的干预。世界上潜伏感染的人口包括 是全球结核病流行的源头。治疗潜伏性感染的新方法 将大大有助于结核病的根除。迫切需要开发一种动物模型， 人类的潜伏期小鼠是LTBl的不良模型;并且我们的初步数据和工作是通过 其他人认为，“潜伏感染”的非人类灵长类动物更可能是“传染病”， 比在人类中用LTB 1观察到的更多的细菌复制和突变应激。感染兔 结核分枝杆菌（Mtb）菌株CDC 1551发展为原发性感染， Mtb杆菌很快在所有兔子组织中变得检测不到。然而，就像人类的潜伏期一样， 结核分枝杆菌持续存在于一个不可检测的（潜伏）状态，因为他们可以重新激活免疫抑制 皮质类固醇我们将更全面地研究在人类潜伏期发生的细菌活动范围， 我们在巴西维托里亚的临床基地。这些结果将用于基准测试，如果需要，微调（修改） 我们的兔子潜伏期模型接下来，我们将使用具有高密度条形码Mtb库的感染来测量（对于 第一次）潜伏期期间Mtb细胞杀死的速率，LTB 1期间存活的克隆的数目，和 在这种疾病状态下的复制和突变率。然后我们将使用高密度条形码结核分枝杆菌， 绘制克隆重新出现的途径。结核病基因敲除将用于鉴定 潜伏期LTB 1所必需的细菌因子。兔潜伏期模型、条形码文库和潜伏期 敲除将被用作评估新的治疗干预措施在根除 少杆菌感染项目1中确定的人类结核病免疫保护的相关性将 在这些疗效研究中提出质疑。与项目4交叉，我们将建立 持久性与潜伏期所需的细菌因素。新的潜伏和持续基因的发现 将识别新的可药物化的目标对潜伏状态的活动。

Project 2 will validate a model of human-like TB latency in New Zealand White rabbits, and apply this model to test interventions against latent TB infections (LTBl). The world's latently infected population comprises the reservoir which feeds the global tuberculosis TB epidemic. Novel approaches to treat latent infections would contribute greatly to TB eradication. There is a critical need to develop an animal model that reflects the human spectrum of latency. The mouse is a poor model for LTBl; and our preliminary data and work by others suggests that "latently-infected" non-human primates are more likely "percolators" with significantly more bacterial replication and mutational stress than is seen with LTBl in humans. Rabbits infected with Mycobacterium tuberculosis (Mtb) strain CDC1551 develop a primary infection that is rapidly contained, after which the Mtb bacilli soon become undetectable in all rabbit tissues. Yet, like human latency, low numbers of Mtb bacilli persist in an undetectable (latent) state because they can be reactivated by immune suppression with corticosteroids. We will more fully study the range of bacterial activity that occurs in human latency at our clinical site in Vitoria, Brazil. These results will be used to benchmark, and if needed, fine tune (modify) our rabbit latency model. Next, we will use infections with a high-density bar-code Mtb library to measure (for the first time) the rate of Mtb cell killing during latency, the number of clones that survive during LTBl, and the replication and mutation rate during this disease state. We will then use high-density bar-coded Mtb to map the pathway of clonal re-emergence during reactivation. Mtb gene knockouts will be used to identify bacterial factors essential for latency LTBl. The rabbit latency model, bar-coded library and latency knockouts will then be used as tools to evaluate the efficacy of new therapeutic interventions in eradicating paucibacillary infection. Correlates of immunological protection identified in human TB in Project 1 will be queried in these efficacy studies. Cross-fertilizing with Project 4, we will establish the overlap between bacterial factors required for persistence vs. latency. The discovery of novel latency and persistence genes will identify new druggable targets active against the latent state.