Development of a broad-spectrum antiviral agent with activity against herpesvirus replication and gene expression

Purpose: To evaluate the broad-spectrum antiviral activity of peptide H9 (H9) in vitro in order to gain insight into its underlying molecular mechanisms. Method: Antiviral activity against Herpes simplex virus type 1 (HSV-1) was determined using thiazolyl blue (MTT) assay. Polymerase Chain Reaction (PCR) was employed to assay H9 antiviral activity against human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The inhibitory effect of H9 on the replication of these viral genes including early genes was assayed by real time-Ppolymerase chain reaction (RT-PCR) and Western blot. Results: H9 possessed significant inhibitory effect on the four different herpesviruses with 50 % inhibitory concentration (IC50) of 1.21 ng/mL (HSV-1). AD169 infection was strongly inhibited with an EC50 value of 0.46 ng/ml. The anti-herpesviral activity of H9 was dose-dependent. The peptide acted primarily during the early stage of infection by detection of the early genes. Conclusion: The results demonstrate that H9 can inhibit the infection of HSV-1, EBV and HCMV. Furthermore, H9 has a broad-spectrum anti-herpesviral effect in vitro based on targeted killing of infected cells expressing genes.