Inhibitory effect of HMGN2 protein on human hepatitis B viral HBeAg and HBsAg expression and DNA replication in HBV-transformed HepG2. 2.15 cell line

AIM: We previously demonstrated that HMGN2 is an antibacterial effector molecule in human LAK cells. This study was to examine the antiviral activity of HMGN2 against human hepatitis virus.METHODS: The purification and identify of HMGN2 proteins including preparative acid-urea polyacymide gel electrophoresis elution, reverse-phase high-performance liquid chromatography, mass spectrum, Western blotting and antimicrobial assay were conducted. The cellular toxicity of HMGN2 to the HepG2.2.15 cells was detected by MTT assay. HBeAg and HBsAg expressions were measured by ELISA. HBV DNA copies were determined by real time quantitative PCR.RESULTS: A bulk of HMGN2 was isolated and purified from the acid soluble proteins of human lymph node, and identified. The HBV-transfected HepG2.2.15 cell line was used in the in vitro assay system.In the range of testing 1-100 mg/L of HMGN2, no cytotoxicity to HepG2.2.15 cells was detected by MTT assay.When incubated with HMGN2 at 1-5 mg/L for 72 h or 144 h, a significant reduction in HBeAg and HBsAg expression and in HBV DNA copies was observed in the supernatant of HepG2.2.15 cells. CONCLUSION: HMGN2 protein markedly inhibits HBV expression and replication in vitro.