Effect of hepatitis B virus X gene on apoptosis and immune molecules of renal tubular epithelial cells

Objective To investigate the effect of hepatitis B virus X (HBX) gene on apoptosis and immune molecules of human proximal renal tubular epithelial cell line (HK-2). Methods The eukaryotic vector pcDNA3.1-myc-HBX containing HBX gene was transiently transfected into HK-2 cells by lipofectamine mediation. Untransfected HK-2 cells and those transfected with empty vector were used as controls. The TLR4 expression was detected by real-time PCR and Western blotting. The apoptosis of cells and expression of MHC-Ⅱ and CD40 were detected by flow cytometry, and the contents of IL-4 and IFN-γ in the supernatant were detected by ELISA. Results Compared with control groups, the number of apoptotic cells was significantly increased in the HBX transfection group (P＜0.05), and the expressions of TLR4, MHC-Ⅱ and CD40 were also significantly increased in the HBX transfection group (all P＜0.05). IFN-γ level in the supernatant of HBX transfection group was higher (P＜0.05), but IL-4 level was lower as compared to control groups (all P＜0.05). Conclusions Over-expression of HBX gene may induce apoptosis of HK-2 cells and up-regulate the expression of immune molecules of renal tubular epithelial cells leading to injury of cells and dysfunction of immunomicroenviroment.