Rapid Publication Targeted Transfection and Expression of Hepatitis B

A soluble DNA carrier system consisting of an asialoglycopro-tein covalently linked to poly-L-lysine was used to bind DNA and deliver hepatitis B virus (HBV) DNA constructs to asia-loglycoprotein receptor-positive human hepatoma cells. 4 d after transfection with surface or core gene expression con-structs, HBsAg and HBeAg in the media were measured to be 16 ng/ml and 32 U/ml per 107 cells, respectively. Antigen production was completely inhibited by the addition of an ex-cess of asialoorosomucoid. On the other hand, asialoglycopro-tein receptor-negative human hepatoma cells, SK-Hepl, did not produce any viral antigens under identical conditions after incubation with HBV DNA complexed to a conjugate com-posed of asialoorosomucoid and poly-L-lysine. Using a com-plete HBV genome construct, HBsAg and HBeAg levels reached 16 ng/ml and 16 U/ml per 107 cells, respectively. Northern blots revealed characteristic HBV RNA transcripts including 3.5-, 2.4-, and 2.1-kb fragments. Intracellular and extracellular HBV DNA sequences including relaxed circular, linear and single stranded forms were detected by Southern blot hybridization. Finally, 42-nm Dane particles purified from the spent culture medium were visualized by electron microscopy. This study demonstrates that a targetable DNA carrier system can transfect HBV DNA in vitro resulting in the production of complete HBV virions. (J. Clin. Invest. 1993. 91:1241-1246.) Key words: hepatitis B virus * replication * targeted expression* asialoglycoprotei