Investigated The Expression Of TLR7 And Cytokine After Hepatitis C Virus Stimulated Murine Microglial

Objective This study aimed to investigate the expression changes of TLR7 and the cytokine IL-6,TNF-αand IFN-α,which mediated by TLR7 signaling pathway, in infected mice microglia BV2 (BV2 cells) by hepatitis C virus(HCV)positive serum,it can help clarify the immune response of TLR7 anti-HCV immune response and the possible immune pathogenesis of HCV on central nervous system injury.Methods BV2 cells were stimulated by which containing 20% HCV positive serum, at different time points after stimulation, cells and the culture supernatant were collected, Real time fluorescence quantitative PCR (RT-qPCR), indirect immunofluorescence flow cytometry and enzyme-linked immunosorbent assay (ELISA) were used to detect TLR7 mRNA, TLR7 protein and IL-6,TNF-α, IFN-αexpression level, while setting the control group and normal human serum group. Using analysis of variance compare the difference of mean among groups.Results TLR7 mRNA and TLR7 protein expressed in BV2 cells. HCV stimulation of BV2 cells, can induce TLR7 mRNA and TLR7 protein levels increased, at 12h, 24 h, 48 h, TLR7 protein expression was significantly higher in HCV positive serum group than the control group and normal human serum group and the difference was significant (P<0.05), normal human serum group compared with the control group was no significant difference (P>0.05). We also observed that TLR7 mRNA and TLR7 protein increased progressively with time. IL-6 and TNF-αexpression levels also gradually increased in supernatant of HCV-positive serum group.After stimulation 48h,IL-6 increased significantly (P<0.05) than the control group and the normal serum group, After stimulation 24h and 48h, TNF-αincreased significantly (P<0.05) than the control group and the normal serum group. After stimulation 24h,IL-6 increased significantly (P<0.05) than the control group and the normal serum group,but the duration was short.Conclusions TLR7 could be activated by HCV positive serum and promoted the innate immune response of microglial,the trends of IL-6 and TNF-αwere consistent with TLR7,IFN-αincreased short term,so TLR7 may play an important role in the pathogenesis of hepatitis C virus on central nervous system injury.