Viral Hepatitis
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 7, 2005; 11(41): 6429-6432
Published online Nov 7, 2005. doi: 10.3748/wjg.v11.i41.6429
VP22 fusion protein-based dominant negative mutant can inhibit hepatitis B virus replication
Jun Yi, Wei-Dong Gong, Ling Wang, Rui Ling, Jiang-Hao Chen, Jun Yun
Jun Yi, Ling Wang, Rui Ling, Jiang-Hao Chen, Jun Yun, Department of General Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an 710033, Shaanxi Province, China
Wei-Dong Gong, Oncology Center, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, Guangdong Province, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 30400380
Correspondence to: Wei-Dong Gong, Oncology Center, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, Guangdong Province, China. gongwd70@fmmu.edu.cn.
Telephone: +86-20-83373939
Received: December 2, 2004
Revised: February 15, 2005
Accepted: February 18, 2005
Published online: November 7, 2005
Abstract

AIM: To investigate the inhibitory effect of VP22 fusion protein-based dominant negative (DN) mutant on Hepatitis Bvrus (HBV) replication.

METHODS: Full-length or truncated fragment of VP22 was fused to C terminal of HBV core protein (HBc), and subcloned into pcDNA3.1 (-) vector, yielding eukaryotic expression plasmids of DN mutant. After transfection into HepG2.2.15 cells, the expression of DN mutant was identified by immunofluorescence staining. The inhibitory effect of DN mutant on HBV replication was indexed as the supernatant HBsAg concentration determined by RIA and HBV-DNA content by fluorescent quantification-PCR (FQ-PCR). Meanwhile, metabolism of HepG2.2.15 cells was evaluated by MTT colorimetry.

RESULTS: VP22-based DN mutants and its truncated fragment were expressed in HepG2.2.15 cells, and had no toxic effect on host cells. DN mutants could inhibit HBV replication and the transduction ability of mutant-bearing protein had a stronger inhibitory effect on HBV replication. DN mutants with full length of VP22 had the strongest inhibitory effect on HBV replication, reducing the HBsAg concentration by 81.94%, and the HBV-DNA content by 72.30%. MTT assay suggested that there were no significant differences in cell metabolic activity between the groups.

CONCLUSION: VP22-based DN mutant can inhibit HBV replication effectively.

Keywords: Hepatitis B virus; Dominant negative mutant; VP22