Modulation of Tolerance and Autoimmunity by Inhibitory Receptors

项目摘要 PD1和LAG3都在控制T细胞耐受、预防自身免疫和限制免疫应答中发挥关键作用。 免疫介导的组织损伤。小鼠中PD1和LAG3的联合遗传缺陷导致致死性 系统性自身免疫，证明了耐受性中关键的PD1/LAG3协同作用。PD1和LAG3也是 调节T细胞耗竭，并协同限制病毒或肿瘤控制。PD 1和LAG 3很有希望 治疗靶点，但很少有人知道他们的作用机制或如何协同介导。项目1 将研究PD1和LAG3相互作用调节致病性之间平衡的机制， 和自身免疫中的保护性免疫反应，使用实验性自身免疫性脑脊髓炎， (EAE)和1型糖尿病模型。我们的总体假设是，PD1和LAG3具有协同作用， 通过控制自身反应性CD4 + FoxP3-T细胞和保护性FoxP3 + T细胞的功能， Treg细胞。我们将使用新的条件性PD1和LAG3敲除小鼠与细胞类型特异性Cre系杂交， 测试这个假设：目的1：PD1和LAG3在控制生成和 Treg细胞的功能我们将检验PD1和LAG3之间的相互作用控制Treg 功能和稳定性，从而影响自身耐受性。令人惊讶的是，我们的初步数据显示， 在Treg中缺乏LAG3和/或PD 1的患者发展改善的自身免疫性疾病。我们将分析相对角色 PD1和LAG3在Treg中的作用，并确定它们如何在EAE和NOD糖尿病中促进Treg功能。我们将 检查在相同或不同Treg中的LAG3/PD1之间或Treg上的PD1/LAG3之间是否存在相互作用 和其他细胞类型，并确定与LAG3/PD1在Treg中相互作用相关的分子途径。 自身免疫目的2：PD1和LAG3在调节自身反应性免疫应答中的相对和协同作用是什么？ CD4 + T细胞？与Treg上缺乏PD1和/或LAG3的小鼠中自身免疫性改善相反，LAG3的丧失 和/或PD1加速自身免疫。这些不同的表型使我们假设， PD1和LAG3协同作用，在介导对自身抗原的耐受性中对CD4 + T细胞具有主导作用。到 为了了解这些差异，需要对Treg和FoxP3-T细胞进行单独分析。为此，我们将 确定PD1和LAG3在调节自身反应性CD4 + T细胞中的相对贡献。我们将 确定LAG3/PD1在CD4+细胞中是否存在协同作用，LAG3和PD1是否在相同或 不同的CD4 + T细胞，以及与CD4 + T细胞中LAG3/PD1之间相互作用相关的分子途径 自身免疫性疾病项目1将与项目2合作，比较 在自身免疫和癌症中Treg中的PD1/LAG3信号，以及项目3，以比较自身免疫和癌症中的PD1/LAG3相互作用。 自身反应性和耗尽的CD4 + T细胞。项目1将使用核心B用于小鼠，核心C用于转录 核心D用于免疫病理学研究，核心A用于统计学支持。

PROJECT SUMMARY PD1 and LAG3 both play critical roles in controlling T cell tolerance, preventing autoimmunity, and limiting immune-mediated tissue damage. Combined genetic deficiency of PD1 and LAG3 in mice results in lethal systemic autoimmunity, demonstrating critical PD1/LAG3 synergies in tolerance. PD1 and LAG3 also are mediators of T cell exhaustion, and synergize to limit viral or tumor control. PD1 and LAG3 are promising therapeutic targets, but little is know about their mechanisms of action or how synergy is mediated. Project 1 will investigate mechanisms by which PD1 and LAG3 interactions regulate the balance between pathogenic and protective immune responses in autoimmunity, using the experimental autoimmune encephalomyelitis (EAE) and type 1 diabetes models. Our overall hypothesis is that PD1 and LAG3 have synergistic effects in tolerance and autoimmunity by controlling functions of self-reactive CD4+ FoxP3- T cells and protective FoxP3+ Treg cells. We will use novel conditional PD1 and LAG3 knockout mice crossed to cell type-specific Cre lines to test this hypothesis: Aim 1: What are the relative roles of PD1 and LAG3 in controlling the generation and function of Treg cells? We will test the hypothesis that interactions between PD1 and LAG3 control Treg function and stability, and thereby impact self tolerance. Surprisingly, our preliminary data show that mice lacking LAG3 and/or PD1 in Treg develop ameliorated autoimmune disease. We will analyze the relative roles of PD1 and LAG3 in Treg, and determine how they contribute to Treg function in EAE and NOD diabetes. We will examine if there are interactions between LAG3/PD1 in the same or distinct Treg or between PD1/LAG3 on Treg and other cell types, and determine molecular pathways associated with LAG3/PD1 interactions in Treg during autoimmunity. Aim 2: What are the relative and synergistic roles of PD1 and LAG3 in regulating self-reactive CD4+ T cells? In contrast to ameliorated autoimmunity in mice lacking PD1 and/or LAG3 on Treg, loss of LAG3 and/or PD1 on all T cells accelerates autoimmunity. These disparate phenotypes lead us to hypothesize that PD1 and LAG3 synergize to have a dominant effect on CD4+ T cells in mediating tolerance to self antigens. To understand these differences, separate analyses of Treg and FoxP3- T cells are needed. In this aim we will determine the relative contributions of PD1 and LAG3 in regulating self-reactive CD4+ T cells. We will determine if there are synergies between LAG3/PD1 in CD4+ cells, if LAG3 and PD1 operate in the same or distinct CD4+ T cells, and molecular pathways associated with interactions between LAG3/PD1 in CD4+ T cells in autoimmune disease. Project 1 will collaborate with Project 2 to compare the impact of disruption of PD1/LAG3 signals in Treg in autoimmunity and cancer, and Project 3 to compare PD1/LAG3 interactions in autoreactive and exhausted CD4+ T cells. Project 1 will use Core B for mice, Core C for transcriptional analyses, Core D for immunopathology studies, and Core A for statistical support.