抗癌胚抗原单克隆抗体可变区基因的克隆及鼠-人嵌合抗体基因在E.coli中的高效表达

The Cloning and Construction of a Murine-Human Chimeric Antibody with Specificity for Carcinoembryonic Antigen and the High Expression of the Chimeric Genes in E. coli

本文采用反转录-聚合酶链反应（RT-PCR）技术,从抗癌胚抗原（CEA）单克隆抗体杂交瘤细胞中克隆到了该抗体的重、轻链可变区（Ⅴ区）基因,并分别将其与人的恒定区基因 C_(3γ)、C_κ相拼接,构建鼠-人嵌合抗体基因。SDS-PAGE和Western-Blot分析结果证实嵌合重、轻链抗体基因在E.coli中得到高效表达,表达量约为菌体可溶蛋白的30％和15％。放射免疫分析法（RIA）和间接ELISA测定的结果表明嵌合重链基因表达产物具有与CEA结合的能力。

The genes encoding the heavy and light chain variable region (VH and VK) of the murine monoclonal antibody with high specificity and affinity for carcinoembryonic antigen have been cloned by using RT-PCR. These genes were combined to the human Cr3 and Ck genes respectively to construct the murine-human chimeric antibody genes. The chimeric heavy and light chains were expressed in E.coli with high levels, the former reaching 30% of the total bacterial protein, while the latter 15%, and characterized by SDS-PAGE, Western blot, RIA and ELISA to demonstrate that the chimeric heavy chain has the CEA-binding ability.