title: Intracellular antibody fragment against hepatitis B virus X protein does not inhibit viral replication.
abstract: Replication of the hepatitis B virus is suppressed by deficiency of the X protein. Although several molecules that block cellular targets of X protein reduce the production of hepatitis B virus progeny, the effect of a specific inhibitor of X protein on viral replication has not been investigated. To block X protein specifically, we adopted an intracellular expression approach using H7 single chain variable fragment (H7scFv), an antibody fragment against X protein. We previously demonstrated that cytoplasmic expression of H7scFv inhibits X protein-induced tumorigenicity and transactivation. In this study, intracellular H7scFv expression inhibits reporter gene transactivation but not viral replication determined by endogenous hepatitis B virus polymerase activity assay and real-time PCR. Our findings imply that intracellular expression of antibody fragment against X protein may not be an alternative therapeutic modality for inhibition of hepatitis B virus replication.
authors.affiliation: Department of Microbiology, Ajou University School of Medicine, San 5 Wonchon-dong Youngtong-gu, Suwon 443-749, Korea.
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Jin
authors.forename: Seung-Ho
authors.initials: SH
authors.lastname: Hong
authors.forename: Kyongmin
authors.initials: K
authors.lastname: Kim
authors.forename: Ho Joon
authors.initials: HJ
authors.lastname: Shin
authors.forename: Sun
authors.initials: S
authors.lastname: Park
mesh_terms: D002460:Cell Line; D006513:Hepatitis B e Antigens / Q000378:metabolism; D006515:Hepatitis B virus / Q000187:drug effects* / Q000502:physiology; D007135:Immunoglobulin Variable Region / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D015534:Trans-Activators / Q000037:antagonists & inhibitors* / Q000276:immunology; D054334:Viral Regulatory and Accessory Proteins; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D006513:Hepatitis B e Antigens; D007135:Immunoglobulin Variable Region; D015534:Trans-Activators; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein