Monoclonal antibodies raised against human acetylcholine receptor bind to all five subunits of the fetal isoform
Monoclonal antibodies raised against human acetylcholine receptor bind to all five subunits of the fetal isoform
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DOI：
10.1016/s0165-5728(99)00086-7
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发表时间：
1999-08-03
影响因子：
3.3
通讯作者：
Vincent, A
中科院分区：
文献类型：
--
作者：
Jacobson, L;Beeson, D;Vincent, A
人肌乙酰胆碱受体(AChR)是一种低聚膜蛋白，由成体形式的(α1)(2)、β亚基和胎儿形式的(α1)(2)、β、γ、β组成。成人AChR是重症肌无力(MG)自身抗体的靶点，阻断胎儿AChR功能的抗体可以穿过胎盘，使发育中的婴儿瘫痪，导致关节痉挛。针对纯化的AChR提出的单抗的特征是结合五个区域，其中三个似乎部分重叠，但这些区域的亚基定位并不清楚，它们被认为主要是在免疫优势的α亚基上。我们研究了单抗与在大肠杆菌中表达的AChR亚单位胞外片段的结合，以及与来自TE671细胞和表达人/鱼雷和鱼雷/小鼠杂交受体的成纤维细胞系的AChR的结合。结合免疫印迹和免疫沉淀实验，我们证明了每个单抗的亚基特异性。结果证实了我们之前的观察，但重要的是，只有两个区域位于人AChR的α亚基上，另外三个区域位于人AChR的β、伽马和德尔塔亚基上。因此，这些单抗可用于研究AChR亚单位在正常组织和疾病组织中的表达，并进一步确定MG患者抗体的结合部位。(C)1999 Elsevier Science B.V.保留所有权利。
The human muscle acetylcholine receptor (AChR) is an oligomeric membrane protein consisting of (alpha 1)(2),beta,delta,epsilon subunits in the adult form and (alpha 1)(2),beta,gamma,delta in the fetal form. The adult AChR is the target for autoantibodies in myasthenia gravis (MG), and antibodies that block the function of fetal AChR can cross the placenta and paralyse the developing baby causing joint contractures. Monoclonal antibodies (mAbs) raised against purified AChR were characterised previously in terms of binding to five regions, three of which appeared to partially overlap, but the subunit localisation of the regions was not clearly established and they were assumed to be mainly on the immunodominant alpha subunits. We have studied binding of the mAbs to AChR subunit extracellular fragments expressed in E. coli, and to AChRs derived from TE671 cells and from fibroblast cell lines expressing human/Torpedo and Torpedo/mouse hybrid receptors. Using a combination of Western blotting and immunoprecipitation experiments, we demonstrate the subunit specificity of each mAb. The results confirm our previous observations but importantly show that only two of the regions are on the alpha subunit, the three others being on the beta, gamma and delta subunits of human AChR. Thus these mAbs should be useful in studies of AChR subunit expression in normal and diseased tissue, and to define further the binding sites of antibodies in MG patients. (C) 1999 Elsevier Science B.V. All rights reserved.