Whittle N, Adair J, Lloyd C, Jenkins L, Devine J, Schlom J, Raubitschek A, Colcher D, Bodmer M
Department of Molecular Immunology, Celltech Limited, Slough, UK.
Protein Eng. 1987 Dec;1(6):499-505. doi: 10.1093/protein/1.6.499.
B72.3 is a mouse hybridoma cell-line secreting an IgG1 antibody which recognises an epitope on a tumour-associated antigen, TAG-72. This high molecular weight mucin-like molecule is found on a variety of human neoplasms, including colon, breast and ovarian carcinomas. Chimaeric immunoglobulin genes with the B72.3 specificity have been constructed by joining the mouse variable regions from cDNA clones to human genomic constant regions using recombinant DNA techniques. The chimaeric heavy and light chain immunoglobulin genes were placed under the control of a strong viral promoter, and co-transfected into COS-1 cells. SDS-PAGE analysis of the 35S-labelled products demonstrated that the transiently expressed antibodies were correctly synthesised and assembled. The specific binding characteristics of the parent B72.3 antibody were retained by the chimaeric antibody in an antigen-based ELISA. This system gave sufficiently high transient expression of the chimaeric antibody molecules to allow rapid physical and immunological characterisation of the engineered gene products.
B72.3是一种小鼠杂交瘤细胞系，可分泌一种IgG1抗体，该抗体可识别肿瘤相关抗原TAG-72上的一个表位。这种高分子量的粘蛋白样分子存在于多种人类肿瘤中，包括结肠癌、乳腺癌和卵巢癌。通过使用重组DNA技术将来自cDNA克隆的小鼠可变区与人类基因组恒定区连接，构建了具有B72.3特异性的嵌合免疫球蛋白基因。将嵌合重链和轻链免疫球蛋白基因置于强病毒启动子的控制下，并共转染到COS-1细胞中。对35S标记产物的SDS-PAGE分析表明，瞬时表达的抗体能够正确合成和组装。在基于抗原的ELISA中，嵌合抗体保留了亲本B72.3抗体的特异性结合特性。该系统使嵌合抗体分子获得了足够高的瞬时表达，从而能够对工程基因产物进行快速的物理和免疫学表征。
