Persistent DNA Hyper-Methylation of the IFN-γ Signaling Pathway During Tuberculosis

项目总结： 结核病是世界上导致死亡和痛苦的主要传染病。 现有的“短程”疗法持续6个月，病死率增加了3%。 在结核病高流行国家为20%，在耐多药结核病环境中为30%。这个 孟德尔人对分枝杆菌病(MSMD)的易感性是一种罕见的基因突变，它会扰乱 免疫系统处于干扰素-γ信号通路的上游或下游。众所周知，结核病 颠覆宿主的免疫控制，然而它这样做的多种机制仍然是完全的 已澄清。 我们的初步数据表明，结核病通过诱导宿主免疫来破坏表观遗传 干扰素-γ信号通路上游和下游的DNA超甲基化，类似于MSMD 突变。此外，我们的初步数据表明，来自研究参与者的免疫细胞 TB可减少干扰素-γ诱导的基因表达上调，从而模拟功能性 在IFNGR、STAT1和IRF1的下游MSMD突变中发现缺陷。我们的预赛 生物信息学分析表明，干扰素-γ诱导的基因表达受到抑制 通过表观遗传抑制a)典型的干扰素-γ信号通路，b)转录因子和c) 非规范的信号通路。 利用现有的生物资料库，我们将评估规范的干扰素-γ的DNA甲基化 信号通路以及重叠和交织的非规范信号通路。我们会 通过评估脱甲基化试剂是否能够逆转DNA，从功能上验证这些结果 干扰素-γ信号通路的高甲基化和恢复干扰素-γ诱导的基因表达。我们会 纵向地对有1)无症状家庭接触者、2)肺接触者的成年人进行这些分析 治疗成功的肺结核和治疗失败的肺结核。 阐明结核杆菌破坏宿主免疫的表观遗传机制是必要的 开发改进的治疗监测工具的步骤和指导的附属宿主的开发 免疫治疗，以改善临床结果。拟议的科学和导师制将拥有 申请者准备成功过渡到独立研究人员。

PROJECT SUMMARY: Tuberculosis (TB) is the world’s leading infectious disease cause of mortality and suffering. Existing “short-course” therapy lasts six grueling months and has case fatality rates of 3% that increase to >20% in TB hyper-endemic countries and > 30% in the setting of multi-drug resistant TB. The Mendelian Susceptibility to Mycobacterial Disease (MSMDs) are rare genetic mutations that perturb the immune system either up or down-stream of the IFN-γ signaling pathway. It is well known that TB subverts host immune control, however the multiple mechanisms it does so remain to be fully elucidated. Our preliminary data demonstrate that TB epigenetically subverts host immunity by inducing DNA hyper-methylation both up and down-stream of the IFN-γ signaling pathway, akin to the MSMD mutations. Further, our preliminary data demonstrates that immune cells from study participants with TB have decreased up-regulate of IFN-γ-inducible gene expression, thereby mimicking the functional defect seen in the down-stream MSMD mutations in IFNGR, STAT1, and IRF1. Our preliminary bioinformatics analysis demonstrates that the inhibition of IFN-γ-inducible gene expression occurs through epigenetic inhibition of a) the canonical IFN-γ signaling pathway, b) transcription factors and c) non-canonical signaling pathways. Using an existing biorepository, we will evaluate the DNA methylation of the canonical IFN-γ signaling pathway as well as overlapping and intertwined non-canonical signaling pathways. We will functionally validate these results by evaluating if de-methylating agents are able to reverse DNA hyper-methylation of the IFN-γ signaling pathway and restore IFN-γ inducible gene expression. We will longitudinally perform these analyses on adults with 1) asymptomatic household contacts, 2) pulmonary TB with treatment success and 3) pulmonary TB with treatment failure. The elucidation of epigenetic mechanisms by which TB subverts host immunity is a necessary step in developing improved treatment monitoring tools and the development of adjunct host directed immunotherapy to improve clinical outcomes. The proposed science and mentorship will have the applicant poised for successful transition to an independent researcher.