B7.1胞外编码区的真核表达及其生物活性

目的　真核表达B7.1细胞外编码区以研究其生物学活性。方法　电穿孔法将重组质粒pDisplay/B7.1(V +C)导入人子宫颈癌细胞株 ,免疫组化及核酸原位杂交法分别检测其蛋白及mRNA表达 ,3 H TdR掺入法测定表达物对T细胞的刺激作用 ;MTT法研究转染细胞 T细胞混合培养引发的细胞毒性杀伤作用。结果　B7.1细胞外区在Hela细胞表面表达 ,所表达的B7.1细胞外区在抗CD3单抗存在的情况下具有刺激T细胞活化的特性 ,重组质粒转染的Hela细胞与T细胞混合培养可引起细胞毒性杀伤。结论　真核表达的B7.1(V +C)具有T细胞共刺激活性 ,可用于构建肿瘤免疫治疗之双功能分子。

Eukaryotic expression of B7.1 extracellular domain and its biological activities

Objective To eukaryotically exp ress B7.1 extracellular domian and investigate its biological activities. Methods Recombinant expression vector pDisplay/B7.1(V+C) wa s transfected into Hela cells by electroporation method. The expression of B7.1( V+C) was identified by immunohistochemistry and in situ hybridization, respectiv ely. In vitro T lymphocyte activation activity was detected by 3H-TdR incoporation method and the aroused cytotoxicity after mixed culture of pDispla y/B7.1(V+C) transfected Hela cell-T cell was observed by MTT method. R esults B7.1(V+C) was expressed successfully on the surface of Hela c ells. The expressed B7.1(V+C) was able to activate T lymphocytes in the pres ence of anti-CD3 monoclonal antibody. Cytotoxicity could be observed when pDisp lay/B7.1(V+C) transfected Hela cells were mixed and co-cultured with T lymphocy tes. Conclusion Eukaryotically expressed B7.1(V+C) main tains its T lymphocyte costimulatory activity, and B7.1(V+C) can be adopted to construct bifunctional molecules for tumor immunotherapy.