Viken H D, Thorsby E, Gaudernack G
Institute of Transplantation Immunology, National Hospital, Norway.
Tissue Antigens. 1995 Apr;45(4):250-7. doi: 10.1111/j.1399-0039.1995.tb02448.x.
To study epitopes of HLA class II molecules, four mouse monoclonal antibodies (mAbs) 13B6, 17F8, 19A1 and 12G6 were made using HLA-DQ8, DP2 and DP4 expressing mouse transfectants for immunization. Three of the mAbs, 13B6, 17F8 and 19A1, bound to all DQ1, 4, 8 or 9 positive B-lymphoblastoid cell lines (B-LCLs) and transfectants tested, i.e. cells carrying the DQB1 genes 0302-3, 0401-2, 0501-3, 0601-4 and 0609 irrespective of the accompanying DQA1 gene. These DQB1 genes code for the shared amino acids (aa) GVY in position 45-47 of the DQ beta chain. DQ1+4+8+9 specific (IIB3) and DQ3 specific (IVD12) reference mAbs inhibited binding of all three mAbs. Testing 13B6, 17F8 and 19A1 with cells made using aa substitutions in various positions of DQ beta 10302 indicated involvement of aa 45 in the epitopes of all three mAbs. The last mAb (12G6) bound to all B-LCLs and all DP transfected cells. However, only some DR transfectants and a single DQ transfectant (carrying DQA10201 and DQB1*0202) bound mAb 12G6. This reactivity pattern correlates with a shared sequence of aa (RFDSDVGE) in position 39-46 of DR- and DQ- and 37-44 of DP beta chains.
为研究人类白细胞抗原（HLA）Ⅱ类分子的表位，使用表达HLA-DQ8、DP2和DP4的小鼠转染细胞进行免疫，制备了4种小鼠单克隆抗体（mAb）13B6、17F8、19A1和12G6。其中3种单克隆抗体13B6、17F8和19A1，能与所有检测的DQ1、4、8或9阳性的B淋巴母细胞系（B-LCL）和转染细胞结合，即携带DQB1基因0302-3、0401-2、0501-3、0601-4和0609的细胞，无论其伴随的DQA1基因如何。这些DQB1基因编码DQβ链第45-47位的共有氨基酸（aa）GVY。DQ1+4+8+9特异性（IIB3）和DQ3特异性（IVD12）的参考单克隆抗体可抑制这3种单克隆抗体的结合。用在DQβ10302不同位置进行氨基酸替换所制备的细胞对13B6、17F8和19A1进行检测，结果表明第45位氨基酸参与了这3种单克隆抗体的表位。最后一种单克隆抗体（12G6）能与所有B-LCL和所有DP转染细胞结合。然而，只有一些DR转染细胞和一个单一的DQ转染细胞（携带DQA10201和DQB1*0202）能与单克隆抗体12G6结合。这种反应模式与DR-β链、DQ-β链第39-46位以及DP-β链第37-44位的共有氨基酸序列（RFDSDVGE）相关。
