目的 :制备鼠抗人B7 1分子的功能性单克隆抗体 ,研究其对高表达相应配基分子细胞的生物学效应。方法 :用两株转人B7 1基因细胞株XG7 B7和L B7分别作为免疫原及检测细胞株 ,利用B淋巴细胞杂交瘤技术制备单克隆抗体。以快速定性试纸分析法鉴定单抗所属的小鼠IgG亚类 ,采用竞争抑制及间接免疫荧光法分析单抗的特异性和亲和力 ,以高表达B7 1分子的恶性淋巴瘤细胞Raji和Daudi为靶细胞 ,分析单抗对其生长的影响。以人多发性骨髓瘤细胞转入B7 1基因细胞株XG1 B7为刺激细胞 ,以人外周血单个核细胞 (PBLs)为反应细胞 ,用MTT法分析单抗的中和活性。结果 :成功地获得了 1株鼠抗人B7 1的功能性单克隆抗体 (克隆 4E5 ) ,属于小鼠IgG1亚类 ,经流式细胞仪分析 ,4E5与PBLs、体外人工诱导的树突状细胞(DCs)、Raji和Daudi的阳性结合率分别为 10 2 %、95 1%、92 7%及 89 2 % ;能完全阻断标准抗人B7 1单抗与相应抗原的结合。同时还发现 ,单抗 4E5能显著地抑制恶性淋巴瘤细胞Raji和Daudi的生长繁殖 ,并能阻断B7分子介导的协同刺激信号的传导。结论 :单克隆抗体 4E5是一株抗人B7 1分子的功能性单抗 ,具有重要的研究和应用价值。 OBJECTIVE: To prepare a functional monoclonal antibody against mouse anti-human B7 molecule and study its biological effect on cells with high expression of corresponding ligand molecule. Methods: Two transgenic B7 1 cell lines XG7 B7 and L B7 were used as the immunogen and the test cell line, respectively, and the monoclonal antibodies were prepared by B lymphocyte hybridoma technique. The McAb subtypes of McAb were identified by rapid qualitative test strip analysis. The specificity and affinity of McAb were analyzed by competition inhibition and indirect immunofluorescence. Raji and Daudi, the target of malignant lymphoma cells highly expressing B7, Cells were analyzed for their effect on their growth. Human multiple myeloma cells were transfected into the B7 1 cell line XG1 B7 as stimulator cells and human peripheral blood mononuclear cells (PBLs) as reaction cells. MTT assay was used to analyze the neutralizing activity of mAb. Results: A monoclonal antibody against human B7 1 (clone 4E5) was successfully obtained and belongs to the subclass of mouse IgG1. Flow cytometry, 4E5 and PBLs, in vitro induced dendritic cells (DCs). The positive binding rates of Raji and Daudi were 10 2%, 95 1%, 92 7% and 89 2% respectively, which could completely block the binding of standard anti-human B7 1 monoclonal antibody to the corresponding antigen. It was also found that mAb 4E5 significantly inhibited the growth and proliferation of Raji and Daudi, a malignant lymphoma cell line, and blocked the B7 molecule-mediated transduction of costimulatory signals. Conclusion: The monoclonal antibody 4E5 is a functional monoclonal antibody against human B7 1 molecule, which has important research and application value.