Construction of recombinant CHO cell strain for high expression of HBsAg

Objective To overexpress hepatitis B virus S gene in CHO cells cultured in serum-free media.Method Plasmid was constructed by cloning of HBV S gene and then it was transfected into CHO cells.After cell screen,the positive clones were identified and isolated into a serum-free media followed by the serological and morphological characterization of the expression product.Result CHO cell strains which can express HBsAg efficiently and stably were obtained.Spherical and filamentous HBsAg could be detected under electronic microscope.The titer of the expression product was up to 1:5000.Conclusion Serum-free media cultured C HO cell strain for overexpression of HBsAg was successfully constructed and the expression product was high antigenic. Key words: Hepatitis B virus;  Hepatitis B suface antigen;  Cell culture