The innate capacity of human T cells to respond to Mycobacterium tuberculosis

描述(申请人提供)：人类对结核分枝杆菌(Mtb)的免疫反应允许建立潜伏期，在某些人中，随后重新激活和疾病。阻止灭菌免疫的宿主-病原体相互作用还不是很清楚。新出现的研究表明，在结核分枝杆菌感染宿主中，存在与保护性免疫相关的具有效应功能的结核分枝杆菌反应性先天T细胞。此外，人类天然T细胞能够使用Toll样受体(TLR)，这种分子通常与先天免疫相关，直接从MTB配体接收共刺激信号。我们假设，MTB反应性先天T细胞和具有功能性先天共刺激受体的NA细胞是促炎介质的来源，如干扰素？在结核分枝杆菌感染初期。这种早期生产的干扰素-？而其他效应分子可能会增强感染结核杆菌的巨噬细胞的抗菌反应，以及感染结核杆菌的树突状细胞产生IL-12。定义和表征结核分枝杆菌反应性先天T细胞和具有功能TLR的NA T细胞的谱系，是疫苗和基于免疫的疗法开发的关键的第一步，这些细胞扩大这些细胞，以支持针对结核杆菌的灭菌免疫反应。这项建议的目的是描述结核分枝杆菌反应性、先天T细胞和NA细胞亚群(包括调节性T细胞)的表型、频率、效应潜力和基因表达谱，这些T细胞亚群利用TLR反应MTB配体，从出生到成年。这项建议的具体目的是研究抗原缺乏经验的新生儿和未感染结核杆菌的婴儿和成年人对结核分枝杆菌的天然T细胞反应。我们将使用一种新的方法在不同年龄的捐赠者中识别和量化非经典限制性Mtb反应性T细胞，并结合流式细胞术、多重细胞因子阵列、无机质谱仪和基因表达谱来描述它们的表型、功能能力和分子图谱。我们将描述新生儿、婴儿和成人对TLR介导性共刺激的反应的表型、功能能力、基因表达谱和T细胞受体多样性。我们还将确定年龄是否影响TLR介导的调节性T细胞抑制功能的改变。我们的方法将使我们能够确定从缺乏抗原经验的宿主(如新生儿)中分离出来的TLR反应性NA-VE T细胞是否代表固有T细胞的一个独特亚群。了解先天T细胞的个体发育和T细胞利用先天受体改变其激活和功能的能力，将有助于我们理解T细胞发育途径的全部潜力，以及它们在宿主免疫防御中的作用。此外，由于新生儿和婴儿非常容易受到感染病原体的严重疾病表型的影响，定义他们的T细胞对结核分枝杆菌等病原体做出反应的天生能力，可以用来为开发下一代疫苗和婴儿使用的疗法提供信息。

DESCRIPTION (provided by applicant): The human immune response to Mycobacterium tuberculosis (Mtb) permits establishment of latency and in some individuals, subsequent reactivation and disease. The host-pathogen interactions that prevent sterilizing immunity are not well understood. Emerging research demonstrates that among Mtb-na¿ve hosts, Mtb-reactive innate T cells with effector functions associated with protective immunity are present. Moreover, human na¿ve T cells are capable of using Toll-like receptors (TLR), molecules typically associated with innate immunity, to directly receive co-stimulatory signals from Mtb ligands. We hypothesize that Mtb-reactive innate T cells, and na¿ve T cells with functional innate co-stimulatory receptors, are a source of pro-inflammatory mediators such as IFN-? during the initial stages of Mtb infection. This early production of IFN-? and other effector molecules may augment antimicrobial responses by Mtb-infected macrophages, as well as IL-12 production by Mtb- infected dendritic cells. Defining and characterizing the repertoire of Mtb-reactive innate T cells, and na¿ve T cells with functional TLR, is an essential first step in the development of vaccines and immune-based therapeutics that expand these cells in order to bolster sterilizing immune responses against Mtb. The objectives of this proposal are to characterize the phenotype, frequency, effector potential, and gene expression profile of Mtb-reactive, innate T cells, as well as na¿ve T cell subsets (including regulatory T cells), that utilize TLR to respond o Mtb ligands, among Mtb-na¿ve hosts from birth to adulthood. The specific aims of this proposal are focused on investigating innate T cell responses to Mtb among antigen-inexperienced neonates and Mtb-naive infants and adults. We will use a novel assay to identify and quantify non-classically restricted Mtb-reactive T cells among donors of different ages, and a combination of flow cytometry, multiplex cytokine arrays, inorganic mass spectrometry, and gene expression profiling to delineate their phenotypes, functional capabilities, and molecular profiles. We will characterize the phenotype, functional capabilities, gene expression profiles, and T cell receptor diversity of na¿ve T cell subsets responsive to TLR-mediated co-stimulation among neonates, infants, and adults. We will also determine if age impacts TLR-mediated alterations of the suppressive functions of regulatory T cells. Our approach will allow us to determine if TLR-responsive na¿ve T cells isolated from antigen-inexperienced hosts, such as newborns, represent a unique subset of innate T cells. Understanding the ontogeny of innate T cells and the capacity of T cells to utilize innate receptors to alter their activation and functio, will advance our understanding of the full potential of T cell developmental pathways, as well as their contribution to host immune defense. In addition, as neonates and infants are exquisitely vulnerable to severe disease phenotypes from infectious pathogens, defining the innate capacity of their T cells to respond to a pathogen such as Mtb, can be used to inform the development of next generation vaccines and therapeutics utilized in infancy.