Antiviral Activities Of Recombinant Cyanovirin-N Against Herpes Simplex Virus Type 1

Objective To explore the antiviral activities of recombinant cyanovirin-N(CV-N) against herpes simplex virus type 1(HSV-1) and to provide a theoretical support for developing new drugs.Methods A stand strain of HSV-1(SM44 strain) was used to investigate the antiviral activities of CV-N in vitro and in vivo.In vitro experiments were carried out in Vero cells, various concentrations of CV-N were applied to different steps of HSV-1 replication cycle, the cytotoxic effect,cytopathic effect(CPE),methyl thiazolyl tetrazolium(MTT) method were used for estimating the influence of CV-N on the virus.The quantity of HSV-DNA was detected by real-time fluorescence quantitative PCR(FQ-PCR),The expression of gB mRNA was observed by in situ hybridization.In vivo experiments,the Kunming mice infected with HSV-1 were treated by various doses of CV-N,the appearance of symptoms and death were recorded.Results CV-N had little cytotoxic effect on Vero cells,it could not directly inactivate HSV-1 infectivity.CV-N not only interfer adsorption of HSV-1 to Vero cells but also inhibite HSV-1 replication in host cells.FQ-PCR results showed that the inhibition rate on HSV-DNA also increased in a dose-dependent and time-dependent manner.In situ hybridization results showed that the HSV-1 gB mRNA was less expressed in CV-N treated group than in the control.When tested in vivo,CV-N at a low concentration (5mg/kg ) could prevent the appearance and development of symptoms of HSV-1 infection in mice,indicating a significant and efficient protection against HSV-1 infection. Conclusion Some of the mechanisms of CV-N against HSV-1 may be explained by the considerable inhibition of virus absorption,virus replication in cells,HSV-1gB gene transcription.CV-N exhibited pronounced antiviral activities agaist HSV-1,further development of CV-N might yield novel candidates of antiviral drugs.