KIR2DL2 Immune Checkpoint as Modulator of T-Cell Effector Function

项目摘要 杀伤细胞免疫球蛋白样受体（KIR）主要由NK细胞表达，尽管其 还描述了在CD 4+、CD 8+和γδ T细胞中的表达。在CD 8 T细胞内，KIR表达是 在淋巴细胞成熟的后期诱导，并被认为调节特异性T细胞效应子功能。 在KIR受体内，KIR 2DL 2调节T细胞效应子功能，因为KIR 2DL 2 + CD 8 + T细胞存在 活化诱导的细胞死亡水平降低，T细胞受体（TCR）后IFN-γ分泌不良 刺激. CD 8 + T细胞中KIR 2DL 2表达的抑制功能的概念得到了以下文献的支持： 观察到表达其同源配体HLA-C1的患者显示总体生存率降低， 无法控制肿瘤的生长。我们的初步数据显示，KIR 2DL 2表达在体内增加， 在患者和过继免疫治疗的临床前模型中过继转移的T细胞。使用 在胰腺肿瘤模型中，我们发现表达KIR 2DL 2的嵌合抗原受体（CAR）-T细胞被 在KIR 2DL 2的配体存在下，它们的细胞毒性显著低于它们的KIR 2DL 2-对应物。此外，委员会认为， CAR-T细胞中的KIR 2DL 2表达与降低的抗肿瘤功效相关，在HLA-I依赖性肿瘤中， 方法，在胰腺癌的鼠模型中。基于这些初步发现，我们假设， KIR 2DL 2表现为T细胞免疫检查点，调节T细胞效应子功能并导致免疫应答。 无效的免疫监视因此，在T细胞制造过程中靶向KIR 2DL 2可能 改善细胞输注后T细胞性能。我们将通过以下方式来检验我们的假设：1）定义调节性 KIR 2DL 2塑造CAR和TCR转基因T细胞抗肿瘤效应子功能的机制。我们 将确定KIR 2DL 2接合在TCR转基因和CAR-T细胞效应子功能中的总体作用。 此外，我们将确定KIR 2DL 2内的哪些区域负责其调节功能。 最后，我们将表征KIR 2DL 2信号相互作用组和触发的下游事件 通过免疫沉淀和蛋白质组学分析确定其配体相互作用。2)改善T细胞性能， 通过消除KIR 2DL 2功能来增强过继性细胞免疫疗法（ACT）。以防止其 抑制作用，KIR 2DL 2表达和/或信号传导的操纵将进行并适应于 CAR-T细胞制造的当前方案。根据预期的结果，我们将首次联系 KIR 2DL 2在治疗性T细胞内的生物学和分子功能。拟议的研究将 增加了我们对KIR 2DL 2生物学机制的理解，并将产生具有更高生物学活性的新型细胞产物。 平移势

Project Summary Killer cell immunoglobulin-like receptors (KIR) are mainly expressed by NK cells, although their expression has also been described in CD4+, CD8+ and γδ T cells. Within CD8 T cells, KIR expression is induced at later stages of lymphocyte maturation and is thought to regulate specific T cell effector functions. Within KIR receptors, KIR2DL2 modulates T cell effector functions, as KIR2DL2+ CD8+ T cells present reduced level of activation-induced cell death, and poor IFN-γ secretion after T cell receptor (TCR) stimulation. The notion of a suppressive function of KIR2DL2 expression in CD8+ T cells is supported by the observation that patients that express its cognate ligand, HLA-C1, showed decreased overall survival and could not control tumor growth. Our preliminary data show that KIR2DL2 expression increases in vivo in adoptively transferred T cells in patients and in preclinical models of adoptive immunotherapy. Using a pancreatic tumor model, we found that chimeric antigen receptor (CAR)-T cells expressing KIR2DL2 were significantly less cytotoxic than their KIR2DL2- counterparts in presence of KIR2DL2’s ligand. Furthermore, KIR2DL2 expression in CAR-T cells was associated with reduced antitumor efficacy, in an HLA-I-dependent manner, in a murine model of pancreatic cancer. Based on these preliminary findings we hypothesize that KIR2DL2 behaves as a T cell immune checkpoint, modulating T cell effector function and leading to an ineffective immunosurveillance. Therefore, targeting KIR2DL2 during T cell manufacturing may improve T cell performance after cell infusion. We will test our hypothesis by 1) Defining the modulatory mechanisms whereby KIR2DL2 shapes CAR- and TCR-transgenic T cell antitumoral effector function. We will determine the overall effect of KIR2DL2 engagement in TCR-transgenic and CAR-T cell effector function. Additionally, we will determine which regions within KIR2DL2 are responsible for its modulatory function. Finally, we will characterize both the KIR2DL2 signaling interactome and the downstream events triggered by its ligand interaction by immunoprecipitation and proteomic analyses. 2) Improving T cell performance for the enhancement of adoptive cell immunotherapies (ACTs) by abrogating KIR2DL2 function. To prevent its inhibitory effect, manipulation of KIR2DL2 expression and/or signaling will be conducted and adapted to the current protocols for CAR-T cell manufacturing. Based on the anticipated results, we will link for the first time the biological and molecular function of KIR2DL2 within therapeutic T cells. The proposed studies will increase our mechanistic understanding of KIR2DL2 biology and will generate novel cell products with high translational potential.