Abstract

An OTHBVS cell line from HepG2 was established. This cell line stably expresses the human hepatitis B virus (HBV) middle S protein that includes the preS2 region which is important for HBV particle entry into the hepatocyte. To establish this cell line, the middle S open reading frame (ORF), with a promoter located in the 5' region and enhancer located in the 3' region, was cloned downstream from the metallothionine (MT) promoter of the OT1529 vector. In this vector, expression of the middle S protein was constructed to be regulated by its own promoter and enhancer. Expression of the large S protein which contains the preS1 region in addition to the middle S protein was designed to be regulated by the MT promoter. When extracts of OTHBVS cells were examined with an S protein detection kit (RPHA, Korea Green Cross Co.), an S protein was detected. Total mRNA of OTHBVS cell examined by northern blot analysis with an S ORF probe revealed small/middle S transcripts (2.1 kb). When the MT promoter was induced by Zn, large S transcripts (2.4 kb) were detected. The GP36 and GP33 middle S proteins were presumably detected, but large S proteins were not detected by immunostain analysis using anti-preS2 antibody.

• Keywords: HBV; HepG2; surface protein; metallothionine promotor; LTR