Construction and expression of recombinant eukaryotic expression vector containing hepatitis B virus surface antigen gene

Using restriction enzymes,the gene fragment encoding HBV antigen middle protein (preS 2+S) was isolated from the recombinant eukaryotic expression plasmid pcDNA S 2S,then subcloned into eukaryotic expression vector pVAX1. In this way,a recombinant kanamycin resistant eukaryotic expression plasmid (pVAX S 2S) containing HBV surface antigen gene was constructed. After identified by restriction enzymes digestion,it was then used to transfect COS7 cells. HBsAg was detected in the supernatant by ELISA,suggesting that the recombinant plasmid could produce HBsAg effectively in vitro. This has provided a basis for further immune response research in vivo.