抗血小板膜糖蛋白单抗SZ—21嵌合Fab片段基因的构建和表达研究

目的 为降低抗血小板膜糖蛋白单克隆抗体SZ－21的免疫原性，克隆了SZ－21可变区基因，构建并表达人－鼠嵌合Fab基因工程抗体。方法 利用基因克隆技术，从杂交瘤细胞系SZ－21克隆出轻、重链可变区基因，然后亚克隆到质粒pSW1中，构建成人－鼠嵌合Fab片段基因质粒pSZ-21，在大肠杆菌中表达。结果 pSZ－21基因构建正确，在大肠杆菌中表达出可溶性抗体片段，表达产物具有与血小板结合的活性。结论 成功地克隆了SZ－21可变区基因，并表达了可溶性人－鼠嵌合Fab基因工程抗体。

Construction and expression of human mouse chimeric Fab fragment gene of mAb SZ 21 ag ainst platelets IIIa

Aim To reduce immunogenecity of monoclonal antibody SZ 21 specific for platelet GPIIIa,the chimeric human mouse Fab fragment gene was constructed and expressed. Methods The VH and VL genes were amplified from the hybridoma cells and subcloned into plasmid pSW1. The plasmid pSZ 21 expressing human mouse chimeric Fab fragment gene was constructed and expressed in E.coli. Results The construction of VH and VL genes were correct, and the expressed products could bind to platelets. Conclusion The variable genes were cloned successfully and the human mouse chimeric Fab fragment was expressed in soluble form.