Evaluation of hepatitis B virus promoters for sustained transgene expression in mice by bioluminescence imaging.

To find new liver-specific expression cassettes for long-term expression of therapeutic genes in the context of pDNA, the function and specificity of hepatitis B virus (HBV)' two hepatic enhancers (EnI and EnII), combined with HBV core and X promoters in cultured cells were evaluated. By bioluminescence imaging and hydrodynamic gene transfer technology, the persistence of transgene expression containing these regulatory sequences in the liver of mice was assessed. Our data indicated that both HBV enhancers were able to stimulate HBV core and X promoter activity in cultured cells of hepatic origin. In vivo, HBV core promoter linked to EnI and EnII (EII-EI-Pc) and X promoter linked to EnI and EnII (EI-EII-Px) could direct a constant and high-level gene expression.