RESUMO
<p><b>OBJECTIVE</b>To investigate the influence of hepatitis B virus C protein on the function of natural killer cell.</p><p><b>METHODS</b>Recombinant eukaryotic expression plasmid pHBI-CMV-HBC was constructed and confirmed by double restrictive enzyme digestion and DNA sequencing analysis. Then the recombinant plasmid was transfected into NK-92 cells with lipofectamine encapsuled. The transfected NK-92 cells containing expressive HBV C protein was confirmed by Western Blot analysis. ELISA was employed to determine the IFN-gamma level secreted by NK-92 cells. And finally the cytotoxicities of NK cells were analysed by MTT colorimetry, with the hepatoblastoma cell line (HepG2) as target cell.</p><p><b>RESULTS</b>Western blotting confirmed the expression of HBV C protein in the NK-92 cells transfected with pHBI-CMV-HBC. NK cytotoxicities and IFN-gamma secretion level of NK-92 cells transfected with recombinant plasmid significantly increased compared to control NK-92 cells transfected with blank plasmid (P < 0.01) and untransfected NK-92 cells(P < 0.01).</p><p><b>CONCLUSION</b>Transient expression of HBC can increase IFN-gamma secretion and cytotoxicities of NK-92 cells.</p>