CAR-T cell treatment of CNS Autoimmunity

项目总结 在没有全球免疫抑制的情况下，存在着对选择性和抗原特异性免疫治疗的巨大需求 用于自身免疫性疾病，如多发性硬化症(MS)和一种密切相关的疾病，称为髓鞘 少突胶质细胞糖蛋白(MOG)抗体病(MOGAD)。这促使人们探索嵌合体 利用抗原受体(CAR)T细胞来特异性地消除自身反应细胞。我们创造了一个独特的 CAR T细胞的一种形式，其中多肽MHCII(PMHCII)与信号域融合以识别 特异性T细胞受体(TCR)。在初步研究中，我们证明了这些pMHCII-CAR T细胞 在体外特异性识别同源TCR，在体内选择性杀伤抗原特异性CD4T细胞。高效 耗尽高亲和力MOG特异性CD4T细胞与预防MOG诱导的实验性 自身免疫性脑脊髓炎(EAE)是MS的动物模型，对pMHCII-CAR结构的修改导致了 更有效地清除低亲和力的MOG反应性T细胞，这与解决 正在进行的EAE。这些数据表明，自身免疫的“激活能”模型类似于化学物质。 反应，在这个反应中，需要更高亲和力的自我反应性T细胞来提供启动 自身免疫，但亲和力较低的T细胞能够维持自身免疫的“反应”。要解决这个问题 假设CAR T细胞技术可以用来消除自身抗原特异的T细胞和清除中央 没有全球免疫抑制的小鼠和人类神经系统(CNS)自身免疫，我们有 制定了三个具体目标。在目标1中，我们将提高体内低亲和力T细胞的删除效率。在AIM 2，我们将测试我们是否能够成功地靶向针对A组T细胞表位的自体反应性CD4T细胞 蛋白质，因为我们预测这种方法将用于治疗人类疾病，其中 T细胞自身抗原是由自身抗体识别的。最后，在目标3中，我们将直接测试MOGAD患者 显示使用pMHCII-CARS发现抗原的MOG特异性T细胞的频率增加。总而言之，我们的 拟议的研究将探索自身免疫的“激活能”模型，并建立一个最佳的CAR T细胞 用于治疗持续自身免疫性疾病的消除低亲和力自身反应性TCR特异性的方法。 最后，我们将开始将这些小鼠的观察结果转化为人类pMHCII-CAR T细胞，并评估它们的 在相关的人类自身免疫性中枢神经系统疾病中的潜在效用。

PROJECT SUMMARY An immense need for selective and antigen-specific immunotherapy without global immunosuppression exists for autoimmune diseases such as multiple sclerosis (MS) and a closely related condition known as myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOGAD). This has prompted exploration of chimeric antigen receptor (CAR) T cell utilization to specifically eliminate autoreactive cells. We have created a unique version of CAR T cells in which peptide MHCII (pMHCII) was fused with signaling domains in order to recognize specific T cell receptors (TCRs). In preliminary studies we demonstrate that these pMHCII-CAR T cells specifically recognize a cognate TCR in vitro and can selectively kill antigen-specific CD4 T cells in vivo. Efficient depletion of high affinity MOG-specific CD4 T cells was associated with prevention of MOG-induced experimental autoimmune encephalomyelitis (EAE), an animal model of MS. Modifications in pMHCII-CAR construction led to greater efficiency in eliminating lower-affinity MOG-reactive T cells which was associated with resolution of ongoing EAE. These data suggest an “activation energy” model of autoimmunity analogous to that of a chemical reaction, in which higher affinity self-reactive T cells are needed to provide the activation energy to initiate autoimmunity, but lower affinity T cells are capable of sustaining the autoimmune “reaction.” To address the hypothesis that CAR T cell technology can be used to eliminate auto-antigen-specific T cells and abrogate central nervous system (CNS) autoimmunity in mice and humans without global immunosuppression, we have formulated three specific aims. In Aim 1 we will improve the efficiency of low affinity T cell deletion in vivo. In Aim 2, we will test whether we can successfully target autoreactive CD4 T cells specific to all T cell epitopes of a protein in mice, as we predict that such an approach would be useful for treatment of human disease where the T cell autoantigen is identified by an autoantibody. Finally, in Aim 3, we will directly test whether MOGAD patients show an increased frequency of MOG-specific T cells using pMHCII-CARs for antigen discovery. In sum, our proposed studies will explore the “activation energy” model of autoimmunity and establish an optimal CAR T cell approach to eliminate low affinity autoreactive TCR specificities for the treatment of ongoing autoimmune disease. Finally, we will begin to translate these murine observations to human pMHCII-CAR T cells and assess their potential utility in a relevant human autoimmune CNS disease.