Abstract
The replication of herpes simplex virus (HSV) type 1 in macrophages grown from spleen cells of mouse strains susceptible to HSV infection in vivo was very sensitive to interferon (IFN). Different types of mouse IFN (α, , γ) exhibited similar antiviral activities. However, treatment of cells with IFN-γ in combination with IFN-α or IFN- resulted in a synergistic inhibition of virus growth. As shown by assaying HSV DNA polymerase, IFN inhibited expression of the -genes. Inhibition of enzyme induction correlated well with the reduction of viral yield. Induction of HSV DNA polymerase was delayed by IFN in a dose-dependent manner. These results show that IFN inhibits HSV replication at an early step prior to or during the synthesis of -proteins.