Determinants of antigen specific CD4 T cell function in tuberculosis

该提案提出了一个为期五年的研究职业发展计划，重点是抗原的研究 结核病（TB）中特异性CD 4 T细胞，长期目标是揭示有关免疫的新信息。 保护结核病，并为这种疾病的有效新疫苗的开发提供信息。候选人是 目前是明尼苏达大学（UMN）传染病系的医学助理教授， 疾病概述的建议是建立在候选人以前的经验，通过增加新的领域， 在先进的T细胞免疫学，国际合作以患者为导向的研究和人类 免疫学和单细胞转录组学。培训目标由以下导师团队代表： 马克·詹金斯和大卫·博尔韦尔，以及UMN的其他主要合作者。拟议的实验和 教学工作将定位候选人与一套独特的跨学科技能，使他的 作为一名专注于结核病免疫学的医生科学家，过渡到独立。 更好地了解结核病中控制CD 4 T细胞功能的因素有助于指导治疗。 开发更有可能引发针对结核病的保护性免疫的候选疫苗。它正在成为 更清楚的是，IFN-γ分泌只是TB中CD 4 T细胞的一种保护功能。另一个关键效应器 结核病中CD 4 T细胞的作用机制仍在研究中，这些免疫功能的决定因素 仍有待充分定性。这个特殊项目的总体科学目标是描述 CD 4 T细胞在感染部位起作用，并确定抗原可用性和T细胞受体（TCR）- 表位亲和力控制这些功能。该提议的前提是CD 4 T细胞的效应活性在 TB感染的位点由所靶向的Mtb抗原的特征决定。核心假设是 1)具有较低亲和力TCR的CD 4 T细胞，以中等丰度靶向Mtb抗原， 多样和上级的功能，和2）在感染部位的抗原特异性CD 4 T细胞执行关键的 Th 1范式之外的效应器功能。为了检验这些假设，提出了以下目标： 1：确定抗原内在因子如何控制TB中的CD 4 T细胞功能，以及目的2：表征CD 4 T细胞功能 人类结核病感染部位的细胞功能和多样性。为了实现这些目标，创新的方法 包括：体内Mtb基因表达的调节，低亲和力TCR的鉴定， 无偏鉴定最近在体内接受TCR刺激的CD 4 T细胞。通过将这些 在小鼠模型中研究了来自个体脑脊液的人T细胞， HIV相关的结核性脑膜炎，使用单细胞转录组学分析，这些研究将描述结核分枝杆菌如何 抗原-内在因子引起不同功能能力和多样性的CD 4 T细胞群。K08 该项目将指导新的结核病疫苗的开发，并促进候选人向独立过渡。

This proposal presents a five-year research career development program focused on the study of antigen specific CD4 T cells in tuberculosis (TB), with the long-term goals to reveal new information about immune protection in TB and inform the development of an effective new vaccine for this disease. The candidate is currently an Assistant Professor of Medicine at the University of Minnesota (UMN) in the Division of Infectious Diseases. The outlined proposal builds on the candidate’s previous experience by adding new domains of expertise in advanced T cell immunology, international collaborative patient-oriented research and human immunology, and single cell transcriptomics. The training objectives are represented by the mentorship team of Marc Jenkins and David Boulware, and other key collaborators at UMN. The proposed experimental and didactic work will position the candidate with a unique set of cross-disciplinary skills that will enable his transition to independence as a physician scientist focused on the immunology of TB. A better understanding of the factors that govern CD4 T cell function in TB could help guide the development of vaccine candidates more likely to elicit protective immunity against TB disease. It is becoming clearer that IFN-g secretion is only one protective function of CD4 T cells in TB. The other key effector mechanisms of CD4 T cells in TB are still being defined, and the determinants of these immune functions remain to be fully characterized. The overall scientific objectives of this particular project are to characterize CD4 T cell functions at the site of infection and to define how antigen availability and T cell receptor (TCR)- epitope affinity govern these functions. The premise of this proposal is that effector activity of CD4 T cells at the site of TB infection is determined by characteristics of the Mtb antigen targeted. The central hypotheses are 1) that CD4 T cells with lower affinity TCRs, targeting Mtb antigens with moderate abundance, have more diverse and superior functions, and 2) that antigen specific CD4 T cells at the site of infection perform key effector functions outside the Th1 paradigm. To test these hypotheses, the following aims are proposed: Aim 1: Determine how antigen-intrinsic factors govern CD4 T cell function in TB, and Aim 2: Characterize CD4 T cell function and diversity at the site of human TB infection. To accomplish these aims, innovative approaches are proposed including: modulation of Mtb gene expression in vivo, identification of lower affinity TCRs, and unbiased identification of CD4 T cells that have recently received TCR stimulation in vivo. By pairing these approaches in the mouse model with studies of human T cells from the cerebrospinal fluid of individuals with HIV-associated TB meningitis, using single cell transcriptomic profiling, these studies will characterize how Mtb antigen-intrinsic factors elicit CD4 T cell populations of varying functional capacity and diversity. This K08 project will guide new TB vaccine development and promote the candidate’s transition to independence.