The role of innate immunity in the acquisition of sterile protection against TB infection

摘要 结核病(TB)是一个主要的全球健康问题。卡介苗(BCG)，唯一的结核病 获得许可的预防性疫苗对肺外结核病(Extra-PTB)80%有效，但有可变 对结核病的疗效，结核病是原发结核病的感染部位。开发更多结核病疫苗的一大障碍 比卡介苗更有效的是，对结核病的免疫保护还不完全清楚。卡介苗产生结核病-- 特异性适应性细胞免疫(ACMI)，这被认为是特别有助于其强大的 对额外结核分枝杆菌有保护作用，但不能对结核分枝杆菌(Mtb)和 不能预防潜在的结核病感染(LTBI)。我们假设Mtb类记忆先天CMI(ICMI)是 一种预防原发结核分枝杆菌感染的机制，可防止下呼吸道感染。一个重要的推论是结核病-- 特定的ICMI将为疫苗诱导的结核病无菌保护提供强有力的措施，这是迫切需要的 开发高效结核病疫苗的工具。使用在结核病队列中收集的样本 印度-美国医疗伙伴关系多中心前瞻性观察性研究(C-Triumph)的研究 Byramjee Jeejeebhoy政府印度浦那医学院(BJMC)和一群卡介苗接受者 在美国登记的结核病暴露可以忽略不计的情况下，我们将调查结核病特异性ICMI作为一种机制 对结核分枝杆菌的无菌保护，以及卡介苗接种可以在多大程度上引发结核分枝杆菌记忆性ICMI。 目的1.确定LTBI-与LTBI+高暴露成人的Mtb ICMI特征 涂片阳性的PTBI。 假设：长期脑损伤--与长期脑损伤相比，高暴露于结核病的个体具有更健壮的Mtb记忆样ICMI 个人。 使用CyTOF技术和为大型数据集设计的系统生物学分析工具，我们将测量 NK细胞、NKT细胞、T细胞和粘膜相关不变T细胞对体外Mtb的大量应答 抗原刺激并分析部分LTBI-和LTBI+高暴露人群的差异 到涂片阳性的PTBI。最显著的独立差异将用于构建较小的流量 细胞仪板，将用于测试剩余的LTBI-和LTBI+高度暴露于结核病的成年人。 目的2.鉴定卡介苗产生的结核分枝杆菌特异性ICMI。 假设：与LTBI-高度暴露于结核病的个人相比，卡介苗治疗会产生 记忆性ICMI到结核分枝杆菌的数量较低和/或仅限于一小部分疫苗接受者。 我们将招募接受卡介苗并接触结核病的成年人，并将他们的结核分枝杆菌ICMI与 使用目标1中描述的工具对高度暴露于结核病的LTBI成人进行的研究。 这项研究的结果有可能改变针对结核分枝杆菌感染的免疫保护模式 取代和/或将ICMI作为长期保护性反应添加到ACMI，从而使 结核病疫苗研发领域。这项研究将通过使用已经收集的数据为C-Triumph提供附加值 外周血单核细胞(PBMC)以实现其免疫学目标。我们还将利用 NIH努力发展BJMC的高级免疫能力。

Summary Tuberculosis (TB) is a major global health problem. Bacille de Calmette et Guérin (BCG), the only TB prophylactic vaccine licensed, is 80% effective against extra-pulmonary TB (extra-PTB), but has variable efficacy against PTB, the site of primary TB infection. A big handicap in the development of TB vaccines more effective than BCG is that immune protection against TB is incompletely understood. BCG generates TB- specific adaptive cell-mediated immunity (aCMI), which is thought to contribute especially to its strong protective effect against extra-PTB, but does not confer sterile immunity against M. tuberculosis (Mtb) and does not protect against latent TB infection (LTBI). We hypothesized that Mtb memory-like innate CMI (iCMI) is a mechanism of protection against primary Mtb infection that prevents LTBI. An important corollary is that TB- specific iCMI will provide a robust measure for vaccine-induced sterile protection against TB, a much needed tool for the development of highly efficacious TB vaccines. Using samples collected in the Cohort For TB Research By The Indo-US Medical Partnership Multicentric Prospective Observational Study (C-TRIUMPH) at the Byramjee Jeejeebhoy Govt. Medical College (BJMC), Pune, India, together with a group of BCG recipients with negligible exposure to TB to be enrolled in the US, we will investigate TB-specific iCMI as a mechanism of sterile protection against Mtb, and the extent to which Mtb memory iCMI can be elicited by BCG vaccination. AIM 1. To identify the Mtb iCMI characteristics that differentiate LTBI- from LTBI+ adults with high exposure to smear-positive PTBI. Hypothesis: LTBI- individuals highly exposed to TB have more robust Mtb memory-like iCMI than LTBI+ individuals. Using CyTOF technology and systems biology analytical tools designed for large datasets, we will measure a large array of NK, NKT,  T and mucosal-associated invariant T (MAIT) cell responses to ex-vivo Mtb antigenic stimulation and analyze the differences between a subset of LTBI- and LTBI+ adults highly exposed to smear-positive PTBI. The most significant independent differences will be used to build a smaller flow cytometry panel that will be used to test the remaining LTBI- and LTBI+ highly TB-exposed adults. AIM 2. To characterize the Mtb-specific iCMI generated by BCG. Hypothesis: Compared with LTBI- individuals highly exposed to TB, BCG administration generates memory-like iCMI to Mtb of lower magnitude and/or restricted to a fraction of the vaccine recipients. We will recruit adults who received BCG and had negligible exposure to TB and compare their Mtb iCMI with that of highly TB-exposed LTBI- adults using the tools described in AIM 1. The results of this study have the potential to shift the paradigm for immune protection against Mtb infection by substituting and/or adding iCMI to aCMI as long term protective responses and, thereby, to revolutionize the field of TB vaccine development. The study will provide added value to C-TRIUMPh by using already collected peripheral blood mononuclear cells (PBMC) to accomplish its immunologic goals. We will also leverage the NIH efforts to develop advanced immunologic capacity at BJMC.