Inhibition of hepatitis B virus replication by dominant negative mutant of VP22 fusion protein

    YI Jun, GONG Weiª²Dong, WANG Ling, LING Rui, CHEN Jiangª²Hao, WANG Hui, WANG Ting

    Department of General Surgery, Xijing Hospital, Fourth Military Medical University, Xi¬ðan 710033, China, Oncology Center, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China

    ¡¾Abstract¡¿ AIM: To investigate the inhibitory effect on hepatitis B virus (HBV) replication with dominant negative (DN) mutant of VP22 fusion protein. METHODS: Fulllength or fractions of VP22 were fused to C terminal of HBV core protein (HBc), and cloned 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 concentration of HBV surface antigen (HBsAg) in the supernatant of cell culture. And MTT assay was performed to detect the cytotoxicity of transgene expression to the host cells. RESULTS: DN mutant of VP22 and its fractions could be expressed in HepG2.2.15 cells, and had no toxic effect on the host cells. The DN mutant could inhibit HBV replication, and the mutant with protein transduction ability had a stronger inhibition than that without. The DN mutant of fullª²length VP22 had the strongest inhibitory effect, reducing the HBsAg concentration by 81.94%. CONCLUSION: DN mutant of VP22 fusion protein can enhance the inhibition of HBV replication. ......