Favre C, Wijdenes J, Cabrillat H, Djossou O, Banchereau J, de Vries J E
UNICET, Laboratory for Immunological Research, Dardilly, France.
Mol Immunol. 1989 Jan;26(1):17-25. doi: 10.1016/0161-5890(89)90015-1.
Five monoclonal antibodies (MAbs B22, B27, 3-6, 32 and 35) specific for human recombinant IFN-gamma were characterized. These MAbs were used to set up quantitative sandwich ELISAs which allowed the detection of 1.25 ng/ml of IFN-gamma when diluted in normal human serum. Epitope mapping of the IFN-gamma molecule using these MAbs demonstrated that antibodies 3-6 and 32 which did not inhibit the biological activity of IFN-gamma recognized an epitope localized on the 15 C-terminal amino acids, suggesting that this portion of the molecule was not implicated in the biological activity of IFN-gamma. Sandwich ELISAs were performed using various pairs of MAbs. The level of reactivity obtained when antibodies B22 and B27 were used simultaneously as catcher and tracer was similar to the result obtained with two antibodies recognizing different epitopes. These results confirm that the IFN-gamma molecule is a dimer in solution and indicate that the two sites of the IFN-gamma dimeric molecule which are associated with the biological activity (epitope B22/B27) are fully exposed. In contrast, the C-terminus is only partially accessible to the antibodies 3-6/32, suggesting that the dimerization of IFN-gamma molecule results in the interaction of regions of the monomers that are homologous and adjacent to the C-terminus.
对五种特异性针对人重组干扰素-γ的单克隆抗体（单克隆抗体B22、B27、3-6、32和35）进行了特性鉴定。这些单克隆抗体被用于建立定量夹心酶联免疫吸附测定法，该方法在用人正常血清稀释时能够检测到1.25 ng/ml的干扰素-γ。使用这些单克隆抗体对干扰素-γ分子进行表位作图表明，不抑制干扰素-γ生物学活性的抗体3-6和32识别位于15个C末端氨基酸上的一个表位，这表明该分子的这一部分与干扰素-γ的生物学活性无关。使用不同的单克隆抗体对进行夹心酶联免疫吸附测定。当抗体B22和B27同时用作捕获抗体和示踪抗体时获得的反应水平与使用识别不同表位的两种抗体获得的结果相似。这些结果证实干扰素-γ分子在溶液中是二聚体，并表明与生物学活性相关的干扰素-γ二聚体分子的两个位点（表位B22/B27）完全暴露。相比之下，C末端仅部分可被抗体3-6/32识别，这表明干扰素-γ分子的二聚化导致单体中与C末端同源且相邻的区域相互作用。
