An anti-preS2 antibody protects human hepatocytes from hepatitis B virus infection

Background : Hepatitis B virus infection is a major problem in liver transplantation. In this study, we examined the potential efficay of a recombinant adenovirus expressing an antibody against the HBV preS2 antigen (Ab-H-HBV-S2) in preventing HBV recurrent infection after liver transplantation. Methods : A gene for humanized antibody against the HBV preS2 antigen was cloned into pDC315, a type 5 adenoviral shuttle plasmid. Recombinant virus was obtained by homologous recom- bination in the 293 packaging cells. The virus containing the Ab-H- HBV-S2 gene was transduced into the rat liver graft during cold preservation. The recombinant virus produced antibody and showed protective effects on human hepatocytes from hepatitis B virus infection in vitro. Results : The recombinant virus titer determined by TCID50 analysis was 5.1×1010 PFU/mL. The concentration of preS2 anti- body in BALB/C nude mice was 16.7 ± 10.5 µg/mL on day 3, 30.9 ± 13.6 µg/mL on day 7, and lasted for 5 weeks after the injection. At a concentration of 0.5 µg/mL or above, the preS2 antibody protect- ed cultured human hepatocytes from hepatitis B virus. Conclusions : Adenovirus-mediated gene transduction of anti- preS2 antibody in the transplanted liver may be a useful approach to prevent hepatitis B infection after liver transplantation. (Acta gastroenterol. belg., 2009, 72, 306-311).