Protective activity of recombinant cytokines against Sendai virus and herpes simplex virus (HSV) infections in mice

The efficacy of recombinant cytokines such as murine interferon-gamma (IFN-gamma), human granulocyte colony-stimulating factor (G-CSF), mouse granulocytic-macrophage colony-stimulating factor (GM-CSF) and human interleukin-1 beta (IL-1 beta) has been examined for augmentation of host resistance against Sendai virus and herpes simplex virus (HSV) infections. All four cytokines were found to protect mice against Sendai virus infection. IFN-gamma afforded protection when administered intranasally but not intravenously several days before the infection. Intranasal administration of G-CSF one day before the infection was the most effective administration route and timing. Intranasal administration of GM-CSF was found to afford protection 1 or 3 days before the infection. IL-1 beta demonstrated therapeutic activity against Sendai virus infection after intranasal administration on the same day as the infection. When each of the cytokines was administered subcutaneously four times daily into cyclophosphamide-treated mice before intravenous infection with HSV, only GM-CSF revealed any protective activity.