重症肌无力乙酰胆碱受体α亚单位的T与B细胞抗原决定基的研究  

B and T cell Epitopes Located Over Acetylcholinergic Receptor α-Subunit in Myasthenia Gravis

作　　者：孙嘉斌 李滨生 吴双斌 郑丽娜 王庆然 

出　　处：《哈尔滨医科大学学报》1995年第1期37-42,共6页Journal of Harbin Medical University

摘　　要：Ｔ与Ｂ细胞对于乙酰胆碱受体α亚单位的反应可出现于大多数重症肌无力患者。我们检测了Ｂ与Ｔ细胞对１０个亚单位（由细胞外、细胞膜间、细胞浆组成的）分子多肽。以免疫酶斑法检测这些多肽的ＩｇＧ抗体分泌细胞，并测定了抗原识别后分泌γ干扰素的辅助Ｔ细胞。结果发现α亚单位全部多肽反应都是免疫原性的。３个以上的多肽同时可在７５％或４８％的重症肌无力患者中起Ｂ或Ｔ细胞抗原决定基作用，但６％或２９％的患者Ｂ或Ｔ细胞对任何多肽无反应。这提示，乙酰胆碱受体其他分子结构可能也具有免疫原性。尚未发现Ｔ与Ｂ细胞免疫优势抗原决定基。在多肽４６－６７反应Ｂ与Ｔ细胞之间呈正相关，但其他多肽的没有发现这种关系。B and T cell responses to the acetylcholine receptor (AChR)α-subunit are found in most patients with myasthenia gravis and considered to be important in disease pathogenesis.We examined the B and T cell repertoires to 10 synthetic peptides encompassing extracellular,transmembraneous and cytoplasmic sections of the α-subunit.Immunospot assays were used,allowing the enumeration of antipeptide IgG antibody secreting cells and of T helper cells secreting interferon-γ(IFN-γ) upon antigen recognition in vitro. Patients with myasthenia gravis had higher numbers of peptide-reactive B and T cells than controls with other neurologital diseases.All parts of the α-subunit were immunogenic,and theee or more poptides served simultanously as B cell epitopes in 75% of the myasthenia gravis patients, and as T cell epitopes in 48%. No immunodominant B or T cell epitopes were detected, and almost any of the peptides included were preferentially recognized by B and/or T cells from individual patients.A positive correlation was found between peptide 46-67 reactive B and T cells,but otherwise no such relations were observed. HLA-DR-DQ genotype could not be shown to influence selective reactivity against the different peptides studied.The results underline that a variety of epitopes of the AChR α-subunit-that differ between petients-are recognized by B and T cells in myasthenia gravis.

关 键 词：重症肌无力 T细胞 乙酰胆碱 受体 干扰素 抗原 

分 类 号：R746.103[医药卫生—神经病学与精神病学]