Expression and Immune Response to Hepatitis C Virus Core Gene Combined Hepatitis B Virus Core Gene with Two Multiple Cloning Sites Vector

OBJECTIVE:To develop a HCV combined HBV DNA-based therapeutic vaccine.METHODS:The HBV core gene and HCV core cDNA were inserted into the eukaryotic expression vector with two multiple cloning sites mammalian expression vector, which can be used for expression of two foreign genes, under the CMV promoter and RSC promoter respectively (named pRSC-HBV/HCV). Cellular expression of pRSC-HBV/HCV was assessed following transfection into SP2/0 cells. The Balb/c mice were immunized by multiple sites intramuscular injection with pRSC-HBV/HCV and the immune responses were detected.RESULTS:The 21-kd and 14-kd core protein was observed. Both anti-HBc IgG and anti-HCV core Ab were detected in all immunized mice. Strong CTL activity of splenocytes against SP2/0 cells expressing both HBV and HCV core proteins were measured in immunized mice both in vitro and in vivo.CONCLUSION:The investigation demonstrated that pRSC-HBV/HCV could generated both humoral immune response and Strong CTL activity against HBcAg and HCV nucleocapsid in mice.