人胰岛素原C肽单克隆抗体的研究

半抗原人胰岛素原C肽(HCP)对小鼠的免疫原性,以蛔虫蛋白作为载体远比牛或小鼠清蛋白为高。将NS-1瘤细胞与HCP-蛔虫蛋白结合物免疫的BALB/c小鼠脾细胞融合,获得12种抗HCP McAb,对其中8种的Ig类和亚类,亲和力及特异性等进行了详细鉴定。不同的HCP片段置换反应结果表明,HCP McAb的抗原决定簇分别位于HCP分子的23～31.22～31及1～22氨基酸区。20例正常成人空腹血浆HCP测定值,用兔多克隆抗血清RIA(0.47±0.16pmol/ml)明显高于MCAb-1 RIA(0.29±0.13 pmol/ml).

Studies on Monoclonal Antibodies Directed Against Human C-peptide

By comparison, it was shown that ascaris protein as carrier was far more effective than BSA and mouse serum albumin to make human c-peptide (HCP) immunogenicity in mice. Twelve monoclonal antibodies (McAb) were obtained after fusion of NS-1 myeloma cells with spleen cells from two BALB/c mice immunized with HCP-ascaris protein conjugate. Eight McAb were characterized and all of them were of IgG1 subclass. Affinities of the McAb for HCP were in the range of 0.03-0.85 X 10(9) mol-1. Although all 8 McAb reacted with both HCP and human proinsulin (HPI), they could specifically recognize human insulin from HPI and were highly species specific without cross-reaction with proinsulin, insulin and c-peptide of other species tested. Through analysis of binding with different HCP fragments, their antigenic determinants were located at either N or C terminal of HCP. The results of plasma HCP radioimmunoassay in 20 normal fasting human adults showed that the value (0.47 +/- 0.16 pmol/ml) determined by rabbit PcAb (R2303) against BSA-HCP was significantly higher than that (0.29 +/- 0.13 pmol/ml) determined by McAb-1.