重症肌无力（MG）是一种自身免疫性疾病，其发病与胸腺和免疫系统失常密切相关，但对胸腺如何引发MG尚不清楚。Treg细胞是影响MG发病的关键要素，其在胸腺中发育、分化和成熟，胸腺髓质上皮细胞（mTECs）是胸腺微环境的主要成分，故推测mTECs为影响Treg细胞发育分化的重要因素。然MG是否存在胸腺mTECs细胞形态或功能的异常，后者影响Treg细胞发育分化是否是MG形成的关键机制？目前尚缺乏研究。课题组前期研究发现，益气解毒复方可改善MG患者的临床症状，调节T淋巴细胞亚群比例水平，其作用靶点可能与免疫调节有关。故在已有的研究基础上，通过EAMG大鼠模型、体外胸腺培养和治疗性胸腺切除术患者，探讨mTECs细胞对Treg细胞数量和功能变化的影响及与MG的相关性，以及益气解毒复方的干预作用，揭示胸腺在MG发病中免疫调节机制及益气解毒复方的干预靶点，为MG的治疗和该方的开发研究提供理论及实验依据。

Myasthenia Gravis（MG）is an autoimmune disease. Its incidence and thymus and immune system disorders are closely related, but it still remains unclear how thymus triggers MG. Regulatory T cell (Treg cell) are a key factor in the pathogenesis of MG, which grow, differentiate and be mature finally in thymus, might play an important role in the pathogenic process of MG. Since medullary thymic epithelial cells（mTECs）serve as a main role in constituting thymic microenvironment, it is supposed that mTECs plays an important factors influencing the growth and differentiation of Treg cells. Then whether mTECs cells affect the development and differentiation of Treg cells is the key mechanism of MG formation? There is still a lack of research. Through previous research, we found out that Yiqijiedu Compound may alleviate the clinical symptoms of MG patients, and regulate the lymphocyte subsets distribution, yet how therapeutic target works is still not well understood. In this review, we intend to establish the model of Experimental Autoimmune Myasthenia Gravis(EAMG) based on our previous research, and the thymus organ will be cultured in vitro, then therapeutic thymus excision will be conducted, through which to explore how the mTECs influence the changes of Treg cells in number and function aspect.and to clarify the intervention effect of Yiqijiedu Compound.Finally to reveal the therapeutic target of Yiqijiedu Compound, thus provide theoretical and experimental basis in the treatment of myasthenia gravis and the developmental research of Yiqijiedu Compound.