Association of Hepatitis B virus infection and the expression of Toll-like receptors 2 and 4 in HepG2 cells / 中华传染病杂志

ABSTRACT

Objective In order to explore the roles of TLR2 and TLR4 in the hepatocyte dam- age caused hy hepatitis B virus infection,and to find whether LPS can affect the damage of hepato- cytes pre-and pos-HBV infection,we detected the changes of TLR2 and TLR4 expressions in hu- man hepatocyte lines HepG2 cells and 2.2.15 cells.Methods HepG2 ceils are most similar to normal human hepatocytes and 2.2.15 ceils are HepG2 cells infected with HBV.We selected these two cell lines to study the differences of TLR2 and TLR4 expression between HepG2 cells before and after HBV infection.In this research,both HepG2 and 2.2.15 cells were stimulated with 0?g/ml, 1?g/ml,10?g/ml,100?g/ml,1 mg/ml and 10 mg/ml LPS.Then the expression of protein of TLR2 and TLR4 were examined by immuno-histochemistry(IHC).The cnRNA of HepG2 and 2.2.15 ceils stimulated with 0?g/ml and 10 mg/ml LPS were examined by reversal transcription-pol- ymerase chain reaction(RT-PCR).Thereafter,the apoptosis of HepG2 and HepG2.2.15 cells were examined by flow cytometry(FC),and the expressions of HBsAg and HBeAg of HepG2.2.15 cells tested with Abbott kits.Results IHC and RT-PCR analysis revealed that TLR2 and TLR4 expres- sions could he detected in both HepG2 and 2.2.15 cells.Moreover,without immune activation, TLR2 and TLR4 expressions were higher in the presence of higher concentrations of LPS.FC analy sis revealed that no apoptosis detected in HepG2 ceils stimulated with LPS in this research,but apop- tosis could be detected in 2.2.15 cells when treated with the same factors.Furthermore,the apoptosis ratios increased with the increase of LPS concentrations.When concentrations of LPS were 1?g/ml, 10?g/ml,100?g/ml,1 mg/ml and 10 mg/ml,the apoptosis ratios were 1.94%,3.03%,3.50%, 3.72%,5.30%,respectively.Abbott analysis revealed that expressions of HBsAg and HBeAg of 2.2.15 cells stimulated with LPS were lower than those not stimulated with LPS.Conclusion HBV can affect the expressions of TLR2 and TLR4 in HepG2 cell lines.LPS can lead 2.2.15 cells to apop- tosis but not HepG2 cells.Although LPS cannot damage normal hepatocytes,it might aggravate hep- atocytes damage when their microenvironment was changed by HBV infection.