Inhibition of Hepatitis B virus replication by small interfering RNA in vivo

Objective To evaluate the inhibitory effect of the small interfering RNA(siRNA) on hepatitis B virus(HBV)in vivo which targets HBV S gene region.Methods An animal model of HBV infection was developed hydrodynamically by injecting pcDNA3.1-HBV together with siRNA through the tail vein of Balb/c.HBsAg was analyzed by time resolved immunofluorometric assay, HBV DNA was analyzed by fluorogenic quantitative PCR(FQ-PCR),HBV S-mRNA was detected by semi-quantitative RT-PCR,and viral specific proteins(HBsAg and HBcAg)in the liver were assayed by immunohistochemical staining.Results In the mice,the siRNA could effectively inhibit the secre- tion of HBsAg,reduce the titers of HBV DNA,and immunohistochemical results also indicated that the number of HBsAg and HBcAg positive cells was reduced.The inhibitory effect of siRNA on HBV lasted 3 clays at least.Conclusion These results demonstrate that the siRNA targeting HBV S gene region can substantially and specifically inhibit HBV replication and expression in vivo.