Project 1 - Modulation of Tolerance and Autoimmunity by Inhibitory Receptors

项目总结 PD1和LAG3在调节T细胞耐受和自身免疫中起重要作用。混合性遗传缺陷 PD1和LAG3在小鼠体内导致致死性系统性自身免疫，显示PD1/LAG3在 宽容。项目1的目标是确定PD1和LAG3控制Treg和Self的机制。 反应性CD4+FoxP3-T细胞在耐受和自身免疫中的作用这些都是基本的和临床的问题 意义，因为PD1和LAG3是T细胞耗竭的关键介质和有希望的治疗靶点，以及 越来越多的人认识到接受检查点治疗的癌症患者的免疫相关不良事件 封锁。更深入地了解PD1和LAG3如何协同工作来调节耐受，可能会使 有效的PD1和LAG3癌症治疗，同时最大限度地减少自身免疫。与EAE加重相反 Pdcd1-/-小鼠，我们的初步数据显示，在Treg中缺乏PD1的小鼠发生了改善的EAE。相反， Treg中的LAG3缺失增加了EAE的严重程度，而Treg中PD1/LAG3的联合缺失降低了EAE的严重程度。这些 研究结果强调了确定PD1/LAG3信号如何整合到不同细胞类型中的必要性 了解干扰这些通路如何影响保护性Treg和致病性自身反应性CD4+FoxP3-T 细胞。基于这些数据，我们假设PD1和LAG3之间的协同作用是通过细胞和 Treg和CD4+FoxP3-T细胞控制致病和保护反应的分子机制不同 在EAE的启动和进展过程中。我们将通过临床、细胞和分子分析来验证这一假设 A)新型可诱导基因敲除小鼠，其中PD1和/或LAG3只能在Treg细胞中暂时删除或仅在 CD4+Foxp3-T细胞和b)小鼠给予PD1和/或LAG3封闭抗体。我们将评估选定的目标 从我们的研究中确定PD1/LAG3协调控制细胞命运和功能的机制。目标1： PD1/LAG3在Treg和自身反应性CD4+FoxP3-T细胞中触发哪些细胞和分子事件 在EAE发病期间是删除还是封锁？我们假设PD1/LAG3相互作用对Treg有明显的影响 在EAE启动期间与CD4+FoxP3-T细胞的比较。我们将定义PD1和/或LAG3缺失如何影响自我反应性 CD4+Foxp3-T细胞激活/分化和Treg激活/功能及LAG3/PD1的整合作用 封锁。目的2：在Treg和自身反应性的CD4+Foxp3-效应器中触发哪些细胞和分子事件 (Teff)细胞在EAE发病后通过PD1/LAG3缺失或阻断？我们预测PD1/LAG3的相互作用可能不同 在EAE的起始期和效应期，由于PD1可以调节T细胞分化命运和效应器反应。 我们将定义PD1和/或LAG3缺失如何影响T细胞和Treg细胞以及PD1/LAG3的综合效应 封锁。项目1将与项目2和项目3合作，比较PD1/LAG3中断在容忍度方面的影响 和T细胞耗竭：EAE和癌症患者中的CD4+FoxP3-T细胞(项目2)，以及EAE患者和CD8+T细胞中的CD4+T细胞 癌症(项目2)和慢性感染(项目3)。项目1将与核心A交互以交换数据，核心 B用于获得独特的小鼠品系，核心C用于转录分析，核心D用于免疫病理研究。

PROJECT SUMMARY PD1 and LAG3 play critical roles in regulating T cell tolerance and autoimmunity. Combined genetic deficiency of PD1 and LAG3 in mice results in lethal systemic autoimmunity, demonstrating PD1/LAG3 synergies in tolerance. The goal of Project 1 is to determine mechanisms by which PD1 and LAG3 control Treg and self- reactive CD4+ FoxP3– T cells in tolerance and autoimmunity. These are issues of fundamental and clinical significance, as PD1 and LAG3 are key mediators of T cell exhaustion and promising therapeutic targets, and there is a growing appreciation of immune-related adverse events in cancer patients treated with checkpoint blockade. A deeper understanding of how PD1 and LAG3 work together to mediate tolerance may enable optimal effective PD1 and LAG3 cancer therapies, while minimizing autoimmunity. In contrast to exacerbated EAE in Pdcd1–/– mice, our preliminary data show that mice lacking PD1 in Treg develop ameliorated EAE. Conversely, LAG3 deletion in Treg increased EAE severity, while combined PD1/LAG3 deletion in Treg reduced EAE. These findings highlight the need to determine how PD1/LAG3 signals are integrated in different cell types to understand how perturbing these pathways impacts protective Treg and pathogenic self-reactive CD4+ FoxP3– T cells. Based on these data, we hypothesize that synergy between PD1 and LAG3 operates by cellular and molecular mechanisms that differ in Treg and CD4+ FoxP3– T cells to control pathogenic and protective responses during EAE initiation and progression. We will test this hypothesis by clinical, cellular, and molecular analyses of a) novel inducible knockout mice where PD1 and/or LAG3 can be temporally deleted only in Treg cells or only in CD4+ Foxp3– T cells and b) mice given PD1 and/or LAG3 blocking antibodies. We will evaluate select targets from our studies to define mechanisms by which PD1/LAG3 coordinate to control cell fate and function. Aim 1: What cellular and molecular events are triggered in Treg and self-reactive CD4+ FoxP3– T cells by PD1/ LAG3 deletion or blockade during EAE onset? We hypothesize that PD1/LAG3 interactions have distinct effects on Treg vs. CD4+ FoxP3– T cells during EAE initiation. We will define how PD1 and/or LAG3 deletion affects self-reactive CD4+ Foxp3– T cell activation/differentiation and Treg activation/function, and integrated effects of LAG3/PD1 blockade. Aim 2: What cellular and molecular events are triggered in Treg and self-reactive CD4+ Foxp3– effector (Teff) cells by PD1/LAG3 deletion or blockade after EAE onset? We predict that PD1/LAG3 interactions may differ in initiation vs. effector phases of EAE, since PD1 can regulate T cell differentiation fates and effector responses. We will define how PD1 and/or LAG3 deletion impacts Teff and Treg cells and integrated effects of PD1/LAG3 blockade. Project 1 will collaborate with Projects 2 and 3 to compare effects of PD1/LAG3 disruption in tolerance and T cell exhaustion: CD4+ FoxP3– T cells in EAE vs. cancer (Project 2), and CD4+ Teff in EAE vs. CD8+ T cells in cancer (Project 2) and chronic infection (Project 3). Project 1 will interact with Core A to exchange data, Core B to obtain unique mouse strains, Core C for transcriptional analyses, and Core D for immunopathology studies.