SEA-scFv as bifunctional antibody : Construction of the bacterial expresion system and its function

本研究通过细菌表达系统制备了sea抗体单链Fv （SEA-scFv）融合蛋白。SEA- scfv具有葡萄球菌肠毒素A（SEA）效应和针对上皮黏液蛋白核心蛋白MUCl（一种癌症相关抗原）的抗体活性。它主要以不溶性形式在细胞质中表达。基因产物经盐酸胍溶解，常规稀释法折叠，金属螯合层析纯化。结果发现SEA-scFv融合蛋白制剂与MUC1和MHC II类抗原发生反应，并且能够增强淋巴因子激活的T细胞表型杀伤细胞对表达MUC1的人胆管癌细胞株TFK- 1的细胞毒性。这种基因工程SEA-scFv融合蛋白有望成为癌症免疫治疗的重要试剂。

A SEA-antibody single chain Fv (SEA-scFv) fusion protein was produced byu bacterial expression system in this study. SEA-scFv has both staphylococcal enterotoxin A(SEA) effects and antibody activity directed at the epithelial mucin core protein MUCl, a cancer associated antigen. It was expressed mostly in the cytoplasm as an insoluble form. The gene product was solubilized by guanidine hydrochloride, refolded by conventional dilution method, and purified using metal-chelating chromatography. The resulting SEA-scFv fusion protein preparation was found to react with MUC1 and MHC class II antigens and had the ability to enhance cytotoxicity of lymphokine activated killer cells with a T cell phenotype against a human bile duct carcinoma cell line, TFK- 1, expressing MUC1. This genetically engineered SEA-scFv fusion protein promises to be an important reagent for cancer immunotherapy.