Summary： The type I interferon and IFNAR play an important role in hepatitis B virus （HBV） infection and anti-HBV therapy. However, its mechanism of action is still poorly understood. To gain more in- sights into the role of type I interferon and type I interferon receptor （IFNAR） in HBV infection, we established an HBV persistent replication IFNAR knockout （IFNAR-/-） mouse model and preliminarily applied this model. At first, the progeny of IFNAR-/- mouse was reproduced. Then hydrodynamic injec- tion with pAAV/HBV1.2 plasmid was conducted to establish the persistent HBV replication IFNAR-/- mouse model. At last, we applied this model to evaluate the effect of nucleoside analogues entecavir （ETV） on HBV replication. It was found that there was no difference in the serum HBsAg and HBeAg levels and HBcAg expression in the liver tissue between the ETV treated groups and normal saline （NS） treated group, but the serum HBV DNA levels were significantly suppressed 10, 25, 40 and 55 days af- ter the ETV treatment [P=0.035, P=0.00, P=0.149 and P=-0.084, IFNAR knockout （KO） control group vs. C57BL/6 ETV groups, respectively; P=0.081, P=0.001, P=0.243 and P=-0.147, IFNAR KO control group vs. IFNAR KO ETV groups, respectively]. Interestingly, there was no difference in serum HBV DNA levels between the ETV treated IFNAR/- and C57BL/6 mice. This result suggests that HBV sup- pression during ETV treatments doesn＇t depend on type Ⅰinterferon and IFNAR. Collectively, persis- tent HBV replication IFNAR/ mouse model that we established is a useful and convenient tool to detect the function of the type Ⅰ interferon and IFNAR in HBV infection and anti-HBV treatments.
