The HCV stimulated expression of TLR9 in BV2 cells at different time points

Objective To analyze the expressions of Toll-like receptor 9(TLR9) mRNA and TLR9 protein in mouse microglia(BV2) at different time points post hepatitis C virus(HCV) stimulation,so as to investigate the expression of TLR9 after central nervous system infection of HCV.Methods Cultured BV2 cells were divided into 3 groups: the HCV-positive serum group,the normal serum group(negative control) and the blank control group.Cells were collected at 4 h,12 h,20 h,36 h after stimulation with different serum,and the expression of TLR9 mRNA detected by RT-PCR and the expression of TLR9 protein detected by flow cytometer(FCM)were compared at different time points.Results TLR9 mRNA and TLR9 protein were present at different time points in each group.The expressions of TLR9 mRNA and TLR9 protein in the HCV-positive serum group were significantly higher than those in other two groups(F=21.921,P0.01;F=32.762,P0.01).In the HCV-positive serum group,the expression of TLR9 mRNA was the highest at 4 h(F=8.364,P0.05),whereas the expression of TLR9 protein was the highest at 20 h(F=16.517,P0.01),the expressions of TLR9 mRNA and TLR9 protein were comparable among other times(P0.05).No significant differences were present between the normal serum group and the control group(P0.05).Conclusions The level of TLR9 mRNA and TLR9 protein in BV2 cells increased after stimulation with HCV-positive serum.TLR9 could play an important role in the central nervous system infection of HCV.