Inhibitory effects of small interference RNA (siRNA) on herpes simplex virus type 2

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: Herpesvirus 2; human; RNA interference; RNA, small interfering