Molecular and functional investigation of the role of CD1 in gamma delta T cell surveillance

γδT细胞是机体对感染性物质和癌症免疫反应的重要组成部分 转化，然而，他们通过其躯体检测抗原的生化机制 重组T细胞受体(TCR)仍不清楚。与αβTCR不同，TCR仅限于识别抗原 在主要组织相容性复合体(MHC)分子的背景下，γδTCR可以识别多种配体 从自身的MHC到完整的、未加工的病毒糖蛋白。我们最近的工作已经建立了CD1 分子作为人类Vδ1γδT细胞亚群的配体，产生强大的功能、生化和 结构性证据。我们试图将我们的研究扩展到人类肠道，在那里γδT细胞，特别是Vδ1+ T细胞占优势。我们的初步数据表明，CD1的识别能力很强，在所有个体中都存在 研究表明，肿瘤中CD1反应性γδT细胞与 健康的邻近组织。因此，这项提议的长期目标是充分描述CD1的反应性 在肿瘤和健康组织中的人群，检查他们的功能效应表型，TCR谱系和 免疫调节信号，除TCR外，还影响募集、激活和潜在的扩张 这些细胞与一种高度相关的人类疾病--结直肠癌有关。我们的第一个目标， 《正常和疾病组织中CD1特异性γδT细胞的特征》，试图用经典的细胞学 扩增辅以直接体外功能和转录分析以分析CD1反应性和非反应性 来自肿瘤和邻近健康组织的反应性T细胞群。这些数据将提供对 与健康组织相比，在肿瘤微环境中调节γδT细胞的信号。我们的第二个 目的：《阐明CD1TCRs与γδ/脂质复合体结合的分子机制》，Will 重点研究这些细胞表达的CD1TCR与γδ/脂类抗原之间的相互作用。 我们将利用蛋白质生物化学、生物物理学和x射线结晶学来阐明其分子机制。 其中CD1TCR识别γδ/脂质。我们的努力将大大扩大我们对具体情况的理解 调节人类健康和疾病中γδT细胞活动的信号。我们的第三个目标，“确定存在” 配体、共刺激和/或共受体分子在CD1特异性γδT细胞激活和/或激活中的作用 结肠的表型“将表征配体和免疫调节信号，这些信号可能调节 CD1反应性γδT细胞在人类结直肠癌中的活性我们将结合RNAseq和 分化试验使用脐带血来源的幼稚Vδ1细胞来检验候选信号的相关性。这 将通过OP9DL1系统得到体外来源的天然Vδ1T细胞的补充。γδT细胞可以是 促炎性或调节性，因此我们试图了解这些细胞在这种疾病中起什么作用，如果有的话。 州政府。这些目标加在一起，将开始揭开人类免疫生物学中γδT细胞的神秘面纱 细胞和分子水平。

γδ T cells constitute an important component of the immune response against infectious agents and cancerous transformations, yet the biochemical mechanisms by which they detect antigen through their somatically recombined T cell receptor (TCR) remain unclear. Unlike αβTCRs, which are restricted to recognizing antigens in the context of Major Histocompatibility Complex (MHC) molecules, γδTCRs can recognize a diversity of ligands ranging from self MHC to intact, unprocessed, viral glycoproteins. Our recent work has established CD1 molecules as ligands for a subpopulation of human Vδ1 γδ T cells, producing robust functional, biochemical and structural evidence. We seek to extend our studies to the human gut, where γδ T cells, and in particular, Vδ1+ T cells, predominate. Our preliminary data suggests that CD1 recognition is robust and present in all individuals examined, and that there exist important functional differences between CD1 reactive γδ T cells in tumors versus healthy adjoining tissue. Thus, the long-term goal of this proposal is to fully characterize this CD1 reactive population in tumors versus healthy tissue, examining their functional effector phenotypes, TCR repertoire and immunomodulatory signals, in addition to the TCR, that shape the recruitment, activation and potential expansion of these cells in the context of a highly relevant human disease, colorectal cancer. Our first aim, “Characterization of CD1-specific γδ T cells in normal and diseased tissue.”, seeks to use classical cellular expansions complemented by direct ex vivo functional and transcript analysis to profile CD1 reactive and non- reactive T cell populations derived from tumor and adjoining healthy tissue. These data will provide insight into the signals that regulate γδ T cells within the tumor microenvironment compared to healthy tissue. Our second aim, “Elucidation of the molecular mechanisms by which γδ TCRs bind to CD1/lipid complexes.”, will focus on characterizing the interaction between the γδ TCRs expressed by these cells and CD1/lipid antigen. We will use protein biochemistry, biophysics and x-ray crystallography to elucide the molecular mechanisms by which the γδ TCR recognizes CD1/lipid. Our effort will significantly expand our understanding of the specific signals that regulate γδ T cell activity in human health and disease. Our third aim, “Determine the presence and role of ligand, co-stimulatory and/or co-receptor molecules in CD1 specific γδ T cell activation and phenotype in the colon” will characterize the ligand and immunomodulatory signals that may regulate the activity of CD1 reactive γδ T cells in the context of human colorectal cancer. We will combine RNAseq and differentiation assays using cord blood derived, naïve Vδ1 cells to test the relevance of candidate signals. This will be complemented by in vitro derived native Vδ1 T cells through the OP9/DL1 system. γδ T cells can be either pro-inflammatory or regulatory, therefore we seek to understand which role these cells play, if any, in this disease state. Together, these aims will begin to unravel the mystery of γδ T cells in human immunobiology, both at the cellular and molecular levels.