Intracellular single-chain antibody against hepatitis B virus core protein inhibits the replication of hepatitis B virus in cultured cells.
Hepatitis B virus (HBV) is one of the major causes of chronic liver diseases and hepatocellular carcinoma. In this study, we used a single chain antibody (sFv), which is a man-made antibody with a strong affinity of immunoglobulin, to inhibit HBV replication. Because HBV replication can only take place in the viral nucleocapsid made of HBV core protein (HBc), we generated anti-HBc sFv and examined whether intracellular anti-HBc sFv could inhibit viral replication in the human hepatoblastoma-derived cell line that produces HBV (HB611). With respect to HBV replication intermediates, both single-stranded and partially double-stranded DNA intermediates were markedly suppressed in the cells expressing anti-HBc sFv, although HBV RNA intermediates were not affected. This suggested that intracellular anti-HBc sFv inhibited HBV DNA replication by inhibiting reverse transcription from HBV pregenome RNA to single-stranded DNA. Because the sFv-HBc complex was detected in the cells expressing anti-HBc sFv by immunoprecipitation analysis but the quantity of intracellular HBc was not affected, the anti-HBc sFv was suggested to inhibit HBV DNA replication by interfering with the function of HBc. These results indicate that intracellular sFv against HBc might be effective as a novel active molecule for gene therapy of hepatitis B.
Yamamoto
M
M
Department of Internal Medicine and Therapeutics, Osaka University School of Medicine, Suita, Osaka, Japan.
Hayashi
N
N
Takehara
T
T
Ueda
K
K
Mita
E
E
Tatsumi
T
T
Sasaki
Y
Y
Kasahara
A
A
Hori
M
M
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000494:pharmacology*; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D016679:Genome, Viral; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006515:Hepatitis B virus / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D018197:Hepatoblastoma; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry; D007135:Immunoglobulin Variable Region / Q000737:chemistry; D008113:Liver Neoplasms; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D014162:Transfection; D014407:Tumor Cells, Cultured; D014779:Virus Replication
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D006512:Hepatitis B Core Antigens; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D011994:Recombinant Proteins