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

确定 trogocytosis 介导的信号传导对 CD4 T 细胞表型和效应功能的作用

• 批准号: 9110454
• 负责人: SCOTT Allen WETZEL
• 金额: $ 7.25万
• 依托单位: UNIVERSITY OF MONTANA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-18 至 2018-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9110454
• 关键词: Accounting; Antigen-Presenting Cells; Antigens; Autoimmune Diseases; Biological; Biological Process; Biology; CD4 Positive T Lymphocytes; CD80 gene; Cell Therapy; Cell membrane; Cells; Cellular biology; Complex; Data; Excision; Flow Cytometry; Frequencies; Generations; IL4 gene; Immune; Immune response; Immune system; In Vitro; Individual; Interferon Type II; Interleukin-4; Lead; Lymphocyte Activation; MAPK3 gene; MHC Class II Genes; Mediating; Membrane; Microscopy; Monitor; Peptide/MHC Complex; Peptides; Phenotype; Process; Production; Proteins; Regulation; Reporting; Research; Role; Signal Pathway; Signal Transduction; Structure; Surface; Synapses; T-Lymphocyte; Up-Regulation; Viral Tumor Antigens; ZAP-70 Gene; base; cytokine; immune function; immunological synapse; in vivo; insight; molecular rearrangement; pathogen; public health relevance; receptor; research study; transcriptome

 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.

 描述（由申请人提供）：CD4+ T 细胞对同源 MHC II 类：抗原呈递细胞 (APC) 上的肽复合物的识别触发 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 细胞通过称为 trogocytosis 的过程从 APC 捕获大的膜片段和相关蛋白。虽然这种现象有可能显着改变单个 T 细胞的生物学特性，但我们目前对该过程的生物学后果了解有限。由于胞吞作用，CD4+ T 细胞在其表面展示免疫突触成分，包括同源 MHC：肽和共刺激分子，例如 CD80。我们之前已经证明，这些分子可能通过与细胞上的受体结合来介导 T 细胞内的细胞内信号传导。在本提案中，我们将研究该信号传导对单个 T 细胞的影响。我们的初步数据表明，这种与 trogocytosis 相关的信号传导维持了效应细胞因子 (IL-4) 的产生，并可能在体外介导 T 细胞向 TH2 表型的转化。该提议的中心假设是，trogocytosis 介导的持续 TCR 信号传导维持效应细胞因子的产生并介导 trog+ T 细胞向 TH2 表型的转化。该假设将使用 2 个具体目标进行检验： 目标 #1) 确定观察到的 trog+ IL-4+ 和 GATA-3hi 细胞频率的增加是否是 trogocytosed 分子信号传导的结果。目标 #2) 确定观察到的 trog+ 细胞 IL-4 和 GATA-3 表达增加是否反映了 TH1 和 TH2 能力的内在差异 执行 trogocytosis 或选择性生存和/或转化为 TH2 的结果。这些实验将使用流式细胞术、qRT-PCR 和 3D 宽视野解卷积显微镜，采用体外和体内方法来监测效应细胞因子的产生，因为 细胞自主信号传导和对通过胞吞作用获得 APC 膜片段的细胞表型的检查。该提案的结果将为了解 trogycytosis 在 T 细胞效应器功能和效应子表型中的作用提供重要的见解，并将为阐明 trogycytosis 的体内功能提供更多的研究线索。