目的　研究抗CD3 抗CD2 0双特异双链抗体的生物学活性。方法　采用亲和层析法纯化本室构建的抗CD3 抗CD2 0双特异双链抗体可溶性表达产物 ,并用SDS PAGE ,Westernblot和分子排阻层析鉴定纯化产物 ;采用FACS法和玫瑰花环试验测定纯化产物与靶细胞的结合活性 ;采用3 H TdR掺入实验和51 Cr释放试验测定该双特异双链抗体的生物学性质。结果　纯化的抗CD3 抗CD2 0双特异双链抗体具有与Jurkat(CD3+)和Daudi细胞 (CD2 0 +)的结合活性 ,且能同时与Jurkat和Daudi细胞结合形成玫瑰花环 ,并能竞争性封闭亲代鼠源性抗体HIT3a和HI47与Jurkat和Daudi细胞的结合位点 ;该双特异双链抗体具有促有丝分裂原作用和介导激活的T细胞杀伤Daudi细胞的活性。结论　抗CD3 抗CD2 0双特异双链抗体具有与亲代鼠源性抗体HIT3a和HI47相同的性质 ,且能介导激活的T细胞杀伤表达CD2 0抗原的肿瘤细胞 ,是一个有望用于B细胞恶性肿瘤临床治疗的双特异性抗体。 Objective To study the biological activity of anti-CD3 anti-CD20 bispecific diabody. Methods The soluble anti-CD3 anti-CD20 double-stranded antibody was purified by affinity chromatography. The purified product was identified by SDS PAGE, Western blot and size exclusion chromatography. The purified product was purified by FACS and rosette assay The binding activity of the product to the target cells was determined by 3 H TdR incorporation assay and 51 Cr release assay. Results The purified anti-CD3 anti-CD20 bispecific diabody had binding activity with Jurkat (CD3 +) and Daudi cells (CD20 +) and could simultaneously bind to Jurkat and Daudi cells to form a rosette and competitively block the parental The murine antibodies HIT3a and HI47 bind to Jurkat and Daudi cells; this bispecific diabody has mitogenic activity and mediates the activity of activated T cells killing Daudi cells. Conclusion The anti-CD3 anti-CD20 double-stranded bispecific antibody has the same properties as the parental murine antibodies HIT3a and HI47, and can mediate the killing of tumor cells expressing CD20 antigen by activated T cells. It is a promising candidate for B cell malignancy Tumor therapy for bispecific antibodies.