Hepatitis B virus vector carries a foreign gene into liver cells in vitro.

Hepatitis B viruses (HBV) specifically target the liver, where they efficiently infect quiescent hepatocytes. Thus, HBV virus has potential to be used as vectors for liver-directed gene transfer. We constructed a new HBV-based vector system. It is composed of transfer vector for transferring a foreign gene, green fluorescence protein (GFP) gene, and a helper vector. When the transfer vector and the helper vector were cotransfected into HepG2 cells, the recombinant HBV (rHBV) particles were generated by trans-complementation between two vectors. The rHBV particles carrying the foreign gene were identified by the Southern blot assay. To test gene delivery and the transduction of the rHBV, we infected primary human hepatocytes and immortalized, HepG2 cells with rHBV in vitro. The results using fluorescence microscopy confirmed that the inserted GFP gene was successfully transferred and expressed both in primary human hepatocytes and HepG2 cells.