title: Alpha/Beta interferon and gamma interferon synergize to inhibit the replication of herpes simplex virus type 1.
abstract: In vivo evidence suggests that T-cell-derived gamma interferon (IFN-gamma) can directly inhibit the replication of herpes simplex virus type 1 (HSV-1). However, IFN-gamma is a weak inhibitor of HSV-1 replication in vitro. We have found that IFN-gamma synergizes with the innate IFNs (IFN-alpha and -beta) to potently inhibit HSV-1 replication in vitro and in vivo. Treatment of Vero cells with either IFN-beta or IFN-gamma inhibits HSV-1 replication by <20-fold, whereas treatment with both IFN-beta and IFN-gamma inhibits HSV-1 replication by approximately 1,000-fold. Treatment with IFN-beta and IFN-gamma does not prevent HSV-1 entry into Vero cells, and the inhibitory effect can be overcome by increasing the multiplicity of HSV-1 infection. The capacity of IFN-beta and IFN-gamma to synergistically inhibit HSV-1 replication is not virus strain specific and has been observed in three different cell types. For two of the three virus strains tested, IFN-beta and IFN-gamma inhibit HSV-1 replication with a potency that approaches that achieved by a high dose of acyclovir. Pretreatment of mouse eyes with IFN-beta and IFN-gamma reduces HSV-1 replication to nearly undetectable levels, prevents the development of disease, and reduces the latent HSV-1 genome load per trigeminal ganglion by approximately 200-fold. Thus, simultaneous activation of IFN-alpha/beta receptors and IFN-gamma receptors appears to render cells highly resistant to the replication of HSV-1. Because IFN-alpha or IFN-beta is produced by most cells as an innate response to virus infection, the results imply that IFN-gamma secreted by T cells may provide a critical second signal that potently inhibits HSV-1 replication in vivo.
authors.affiliation: Department of Microbiology and Immunology, Tulane University Health Sciences Center, Program in Molecular Pathogenesis and Immunity, New Orleans, Louisiana 70112, USA.
authors.forename: Bruno
authors.initials: B
authors.lastname: Sainz
authors.forename: William P
authors.initials: WP
authors.lastname: Halford
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002522:Chlorocebus aethiops; D004357:Drug Synergism; D005123:Eye / Q000821:virology; D005260:Female; D006561:Herpes Simplex / Q000188:drug therapy / Q000276:immunology* / Q000821:virology; D018259:Herpesvirus 1, Human / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D016898:Interferon-alpha / Q000494:pharmacology / Q000627:therapeutic use; D016899:Interferon-beta / Q000494:pharmacology / Q000627:therapeutic use; D007371:Interferon-gamma / Q000494:pharmacology / Q000627:therapeutic use; D007372:Interferons / Q000494:pharmacology* / Q000627:therapeutic use; D016849:Keratitis, Herpetic / Q000188:drug therapy / Q000276:immunology / Q000821:virology; D051379:Mice; D008813:Mice, Inbred ICR; D012668:Trigeminal Ganglion / Q000821:virology; D014709:Vero Cells; D010948:Viral Plaque Assay; D017735:Virus Latency; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D000998:Antiviral Agents; D016898:Interferon-alpha; D016899:Interferon-beta; D007371:Interferon-gamma; D007372:Interferons