特异性乙酰胆碱能受体嵌合抗原受体T细胞（AChR-CAR T）治疗实验性自身免疫性重症肌无力鼠模型的有效性和机制研究

Myasthenia gravis (MG) is an autoimmune disease with definite pathogenic antibody. Our previous studies demonstrated some therapeutic effect of tacrolimus and small dose of Rituximab by targeting T and B cells in MG patients. However, new technologies in precise elimination of acetylcholine receptor (AChR) antibody-secreting B cells are deficient. In current study, we will engineer a novel chimeric antigen receptor (CAR) T cell, named AChR-CAR T cell, with surface expression of AChR α subunit to specifically target the anti-AChR B cells. We will firstly evaluate the in vitro and in vivo efficacy of AChR-CAR T cells and then intravenously adoptive transfer to EAMG rat, quantify the serum antibodies, cytokine production, behavior analysis and neuromuscular junction pathology, to analyze the in vivo therapeutic efficacy and off-target effect. Additionally, the potential mechanism will be investigated by cytokines and lymphocytes analysis, in vitro lymphocyte stimulation test and B cell killing test. Promisingly, the implementation of this current study will provide more pre-clinical evidence for antigen-specific CAR T cells as an effective strategy in MG.

重症肌无力是致病性抗体明确的自身免疫性疾病，本课题组前期分别采用他克莫司和小剂量利妥昔单抗以T、B细胞为靶点进行治疗研究，虽能部分改善治疗现状，但缺乏特异性。因此，探索针对分泌乙酰胆碱受体（AChR）抗体B细胞的精准治疗手段非常必要。在本研究中，我们将AChRα亚基表达在嵌合抗原受体（CAR）T细胞的胞外段，该抗原拟将T细胞靶向至产生AChR抗体的特异性B细胞，从而实现T细胞介导的特异性杀伤作用，在不影响整体体液免疫的前提下改善MG的病情。本课题将评估人源性AChR-CART细胞在体外和体内的特异性杀伤效应，然后以EAMG大鼠为主要疾病模型，经尾静脉回输到大鼠体内，设立不同治疗对照组，通过行为学、血清抗体和病理评估其疗效、脱靶效应和安全性。此外，通过研究大鼠外周血细胞因子、淋巴细胞亚群的变化，以及淋巴细胞体外刺激实验和B细胞体外杀伤实验，探索治疗的免疫机制，为用于临床提供充分的实验依据。