Cloning and expression of genotype B and C hepatitis B virus in eukaryotic cells / 中华传染病杂志

ABSTRACT

Objective To construct recombinant full length genotype B and C hepatitis B virus (HBV)and to examine HBV DNA replication and hepatitis B surface antigen(HBsAg),hepatitis B e antigen(HBeAg)expressions in Huh7 cells. Methods The full length genotype B and C HBV DNA were extracted and amplified from two HBV infected patients. The recombinant plasmids were constructed by inserting the amplified HBV fragments into the eukaryotic expression vector,pHY106,which were then transfected into Huh7 cells. The cells transfected with blank pHY106 vector were used as control. HBV DNA replication at 72 hours of transfection was detected by Southern blot. The HBV DNA levels in Huh7 cells at 24,48,72,96 and 120 hours of transfection were determined by real-time polymerase chain reaction(PCR).Meanwhile, the HBsAg and HBeAg expression levels in the supernatants at 24,48,72,96 and 120 hours were determined by enzyme linked immunosorbent assay(ELISA).Results The recombinant plasmids expressing genotype B or C HBV DNA were successfully constructed.The HBV replicative intermediates in HBV core particles,including rcDNA dsDNA and ssDNA,were detected by Southern blot.HBV DNA level could reach 8 lg copy/mL which was by real-time PCR. HBsAg and HBeAg levels determined by ELISA peaked at 72 hours after transfection and then declined gradually. Conclusions The recombinant plasmids inserted with genotype B or C HBV DNA are constructed successfully, which can express high levels of HBsAg and HBeAg in Huh7 cells. This system provides a platform for studying the pathogenesis of B and C genotype HBV, the interaction between HBV and host, as well as exploiting new drugs against HBV.