Determining the role of trogocytosis-mediated signaling on CD4 T cell phenotype and effector functions

 描述（由申请人提供）：CD 4 + T细胞识别抗原呈递细胞（APC）上的同源MHC II类：肽复合物，触发T-APC界面处的大规模分子重排，形成称为免疫突触的结构。在突触处，T细胞在称为胞刺的过程中从APC捕获大的膜片段和相关蛋白。虽然这种现象有可能显著改变单个T细胞的生物学，但我们目前对这一过程的生物学后果只有有限的了解。由于胞刺作用，CD 4 + T细胞在其表面上展示免疫突触组分，包括同源MHC：肽和共刺激分子，如CD 80。我们先前已经表明，这些分子介导T细胞内的细胞内信号传导，可能是通过接合细胞上的受体。在本提案中，我们将研究这种信号传导对单个T细胞的影响。我们的初步数据表明，这种胞啃相关的信号维持效应细胞因子（IL-4）的生产，并可能介导T细胞转化为TH 2表型在体外。该提议的中心假设是胞刺介导的持续TCR信号传导维持效应细胞因子产生并介导trog+ T细胞转化为TH 2表型。将使用2个具体目的来检验该假设：目的#1）确定观察到的trog+ IL-4+和加塔-3 hi细胞频率的增加是否是来自胞吞分子的信号传导的结果。目的#2）确定所观察到的trog+细胞的IL-4和加塔-3表达的增加是否反映了TH 1和TH 2表达IL-4和GATA-3的能力的内在差异。 进行胞啃或选择性存活和/或转化为TH 2的结果。使用流式细胞术、qRT-PCR和3D宽视野去卷积显微镜，这些实验将涉及体外和体内方法以监测作为细胞因子释放的结果的效应细胞因子产生。 细胞自主信号传导和检查通过胞啃作用获得APC膜片段的细胞的表型。从这一建议的结果将提供重要的洞察到的作用，trogycytosis的T细胞效应功能和效应表型，并将lad到额外的调查线，以阐明在体内的功能，trogocytosis。

 DESCRIPTION (provided by applicant): CD4+ T cell recognition of cognate MHC class II:peptide complexes on antigen presenting cells (APC) triggers large-scale molecular rearrangements at the T-APC interface forming a structure called the immune synapse. At the synapse, T cells capture large membrane fragments and associated proteins from the APC in a process termed trogocytosis. While this phenomenon has the potential to significantly alter the biology of the individual T cell, we currently have only limited understanding of the biological consequences of this process. As a result of trogocytosis, CD4+ T cells display immunological synapse components on their surface including cognate MHC:peptide and costimulatory molecules, such as CD80. We have previously shown that these molecules mediate intracellular signaling within the T cell, presumably by engaging their receptors on the cell. In this proposal we will examine the impact that this signaling has on the individual T cell. Our preliminary data suggests that this trogocytosis-associated signaling maintains effector cytokine (IL-4) production and may mediate the conversion of T cells to a TH2 phenotype in vitro. The central hypothesis of this proposal is that is that trogocytosis-mediated, sustained TCR signaling sustains effector cytokine production and mediates the conversion of trog+ T cells to a TH2 phenotype. This hypothesis will be examined using 2 specific aims: Aim #1) Determine whether the the observed increase in the frequency of trog+ IL-4+ and GATA-3hi cells is the result of signaling from the trogocytosed molecules. Aim #2) Determine whether the observed increase in IL-4 and GATA-3 expression by trog+ cells is reflective of an intrinsic difference in the ability of TH1 and TH2 to perform trogocytosis or the result of selective survival and/or conversion to TH2. Using flow cytometry, qRT-PCR and 3D wide-field deconvolution microscopy, these experiments will involve both in vitro and in vivo approaches to monitor effector cytokine production as a result of cell- autonomous signaling and examination of the phenotype of the cells that have acquired APC membrane fragments via trogocytosis. The results from this proposal will provide important insight into the role of trogycytosis in T cell effector function and effector phenotype and will lad to additional lines of inquiry to elucidate the in vivo functions of trogocytosis.