ABSTRACT
ObjectiveTo explore the effect and mechanism of Toll-like receptor 4(TLR4) ligand LPS-mediated inhibition hepatitis B virus (HBV) replication in Bewo cells.MethodsFirst of all,2 μg 1.3-fold HBV recombinant vector pcDNA3.1 ( + )-HBV1.3 were transfected into Bewo cells,after 12 h,the cells were treated with LPS for 3 d.To observe the kinetics of IFN-β and TNF-α expression in Bewo cells,the Bewo cells were exposed to TLR4 ligand LPS.And the effect of pyrrolidine dithiocarbamate ( PDTC),an inhibitor of NF-κB,on LPS-induced cytokines was also observed.The HBsAg,HBeAg and HBV DNA level in the culture supernatant were detected by Microparticle Enzyme Immunoassay (MEIA) and fluorescence quantitative PCR,respectively,and the expression of IFN-β,TNF-α,TRIF and MyD88 was detected by ELISA and RT-PCR,respectively.ResultsCompared with control group,LPS could significantly suppress HBV replication in Bewo cells ( P ＜0.01 ),and it could induce the production of TNFα in Bewo cells ( P ＜ 0.05 ),in time-and dose-dependent manners.PDTC strongly inhibited LPS and induced TNF-α production,but had no much effect on IFN-β in Bewo cells ( P ＜ 0.001 ).Compared with control group,the mRNA levels of MyD88 were significantly induced by LPS in the Bewo cells transfected with this recombinant vector( P ＜ 0.001 ).ConclusionsTLR4 ligand LPS could significantly suppress HBV replication by inducing TNF-α production in Bewo cells mainly via the MyD88/ NF-κB signal pathway.