title: Expression of hepatitis B surface antigen in human cells by a recombinant BK virus DNA vector.
abstract: The construction of the first stable human cell lines that express and secrete authentic hepatitis B virus surface antigen (HBsAg), using a BK virus (BKV) episomal plasmid vector, is described. The amount of HBsAg produced by BKV vectors (up to 600 ng/10(7) cells) was comparable to other eukaryotic vector systems. The level of HBsAg expression remained the same regardless of the orientation of the HBsAg gene, substitution of the HBsAg gene promoter with the mouse metallothionein I gene promoter or the tissue origin of the human cell lines used to establish stable cellular transformants. Northern blot analysis also indicated synthesis of normal HBsAg transcripts. Surprisingly, however, the vectors were maintained at far lower than expected copy number (one to five copies/cell). Reasons for this are discussed.
authors.affiliation: Institute of Microbiology, University of Ferrara, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Caputo
authors.forename: G
authors.initials: G
authors.lastname: Barbanti-Brodano
authors.forename: P
authors.initials: P
authors.lastname: Reschiglian
authors.forename: M
authors.initials: M
authors.lastname: Gianni
authors.forename: M
authors.initials: M
authors.lastname: Mottes
authors.forename: P
authors.initials: P
authors.lastname: Miranda
authors.forename: G
authors.initials: G
authors.lastname: Milanesi
authors.forename: B B
authors.initials: BB
authors.lastname: Knowles
authors.forename: R P
authors.initials: RP
authors.lastname: Ricciardi
mesh_terms: D001739:BK Virus / Q000235:genetics*; D002460:Cell Line; D004274:DNA, Recombinant; D005822:Genetic Vectors; D006514:Hepatitis B Surface Antigens / Q000096:biosynthesis*; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008668:Metallothionein / Q000235:genetics; D011120:Polyomavirus / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*; D011994:Recombinant Proteins / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
chemical_list: D004274:DNA, Recombinant; D006514:Hepatitis B Surface Antigens; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D008668:Metallothionein