Chen Feng, Guo Ya-Bin, Liu Shi-Lian, Zheng De-Xian, Liu Yan-Xin
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing 100005, China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2008 Dec;30(6):690-5.
To construct the human/mouse chimeric antibody of a functional anti-death receptor 5 (DR5) antibody. Methods The viable region of light chain (VL) and viable region of heavy chain (VH) genes of anti-DR5 antibody were amplified and cloned into the light- and heavy-chain expression vectors respectively, then the recombinant plasmids were co-transfected into dihydrofolate reductase(-) Chinese hamster ovary cell (CHO-dhfr(-)) for expression. The positive clone was screened by the two selective genes (neo and dhfr). The humanization and specificity of chimeric antibody was identified by ELISA and Western blotting, and the tumoricidal activity of the expressed chimeric antibody was detected by tetrazolium salt phenazine methosulfate assay.
The expression vectors stably expressed chimeric antibody in CHO-dhfr(-). In the cell supernatant of the F4' clone, the human IgG heavy constant region and light constant region were identified. Moreover, the secreted chimeric antibody retained the binding capacity to the antigen (DR5) and decreased the cell viability of Jurkat and HCT116 cells to 73.15% and 77.30% in vitro respectively.
The human/mouse anti-DR5 chimeric antibody has been successfully expressed in eukaryotic cells and shows tumoricidal activity, which establishes a foundation for the future research of humanized antibody medicine.
构建具有功能的抗死亡受体5(DR5)抗体的人/鼠嵌合抗体。方法:扩增抗DR5抗体轻链可变区(VL)和重链可变区(VH)基因,并分别克隆到轻链和重链表达载体中,然后将重组质粒共转染到二氢叶酸还原酶缺陷型中国仓鼠卵巢细胞(CHO-dhfr(-))中进行表达。通过两个选择基因(neo和dhfr)筛选阳性克隆。采用酶联免疫吸附测定(ELISA)和蛋白质免疫印迹法(Western blotting)鉴定嵌合抗体的人源化及特异性,采用四氮唑盐吩嗪甲磺酸盐法检测表达的嵌合抗体的杀瘤活性。
表达载体在CHO-dhfr(-)细胞中稳定表达嵌合抗体。在F4'克隆的细胞上清液中,鉴定出了人IgG重链恒定区和轻链恒定区。此外,分泌的嵌合抗体保留了与抗原(DR5)的结合能力,体外分别使Jurkat细胞和HCT116细胞的活力降低至73.15%和77.30%。
人/鼠抗DR5嵌合抗体已在真核细胞中成功表达并具有杀瘤活性,为后续人源化抗体药物的研究奠定了基础。