Long term expression of small interfering RNA targeting M2 gene induces effective inhibition of influenza A virus replication

Abstract

RNA interference (RNAi) provided a powerful new means to inhibit specific virus infection. Here, a lentiviral vector with H1- short hairpin RNA (shRNA) expression cassette and enhanced green fluorescence protein (EGFP) as surrogate marker is adopted to deliver small interfering RNAs (siRNAs) into mammalian cells. Upon the lentiviral integration property, we have successfully built up persistent cell lines to express siRNAs. Based on the established stable cell lines, the inhibition efficiency of the rationally designed siRNAs specific for conserved genome of influenza A virus has been well studied. The results showed that siRNA targeting influenza M2 gene (siM2) conferred more effective inhibition of virus replication compared with previously reported siRNA targeting NP gene (siNP). This high suppressive effect of siM2 was observed not only for H1N1 virus but also for highly pathogenic avian influenza H5N1 subtype. In conclusion, our study suggested M2 gene can be an optimal RNAi target for antiviral therapy. Those findings provide rational information for the development of siRNAs as prophylaxis and therapy for influenza virus infection in humans.