Abstract:

Objective To investigate the antiviral effect of siRNA on herpes simplex virus type 2 （HSV-2） in vitro. Methods Different siRNA duplexes targeting HSV-2 VP16 and DNA polymerase genes were designed and chemically synthesized. The antiviral effect of siRNA duplexes was evaluated by virus yield reduction assay. In detail, Vero cells cultured in 24-well plates were transfected with different siRNAs 4 hours before （preventive effect experiment） or 1 hour after （therapeutic effect experiment） the inoculation with HSV-2 （0.02 to 0.05 plaque forming unit/cell）. After additional culture for 40 to 48 hours, the expression of target genes in Vero cells was measured by real-time quantitative reverse transcription （RT）-PCR. Results Both the siRNA duplex VP2-1 targeting HSV-2 VP16 and DP2-1 targeting DNA polymerase gene resulted in a remarkable decrease in viral titer by about 1 log10 in both the preventive and therapeutic effect experiment. As the preventive effect experiment showed, the expression of HSV-2 VP16 mRNA was decreased markedly by 58.6％ and 79.5％ by VP2-1, respectively, and that of HSV-2 DNA polymerase mRNA by 59.8％and 77.4％ by DP2-1, respectively, at 6 and 12 hours after the infection. Conclusions The siRNA duplexes targeting HSV-2 VP16 and DNA polymerase genes could inhibit the proliferation of HSV-2. Hence, HSV-2 VP16 and DNA polymerase genes may serve as the target genes of RNA interference to inhibit HSV-2 replication.

Key words: siRNA