抗CD3人源化抗体恒定区突变体的制备及其生物学活性

为了降低抗CD3人源化抗体hu12F6对T细胞的激活作用以克服首剂效应 ,构建了恒定区特定位点突变的hu12F6重链表达载体 ,将其与hu12F6的轻链表达载体共转染CHO细胞 .ELISA和RT PCR证实 ,恒定区特定位点突变的人源化抗体hu12F6m在CHO细胞中获得了表达 .竞争抑制实验证实hu12F6m具有与原鼠源抗体及hu12F6相似的特异性和亲和力 .增殖实验表明hu12F6m对T细胞的刺激作用明显弱于hu12F6 .实验结果为深入探讨hu12F6m的生物学特性奠定了基础 .

Preparation of a Humanized Anti-CD3 Antibody Containing Mutated Constant Region and Its Biological Activity

In order to reduce the mitogenic activity of a humanized anti-CD3 antibody (hu12F6) and overcome its first dose effect, the heavy chain expression vector of hu12F6 containing mutated Fc region was constructed and cotransfected with the light chain expression vector of hu12F6 into CHO cells. The expression of humanized antibody containing mutated Fc region (hu12F6m) was confirmed by ELISA and RT-PCR. Competitive binding assay demonstrated that hu12F6m possessed binding affinity and specificity similar to native 12F6 or hu12F6. T cell preliferation assay showed that hu12F6m exhibited significantly less mitogenic activity than hu12F6. These results might provide a foundation for further study of biological activities of hu12F6m.