Effects of different interferons on the replication of herpes simplex virus in human T lymphocytes

Human T cells were activated with PHA and after 48 h they were treated with preparations of different human interferons (IFNs). After a further incubation period of 24 h, the cells were washed and infected with herpes simplex virus type 1 (HSV-1). Reduced virus titers were observed in T cells pretreated with IFN-alpha or IFN-beta, whereas IFN-gamma showed no antiviral effects. These findings indicate that IFN-gamma does not exert protection against viral infection in this system. We investigated the synthesis of HSV-coded early and late proteins in T cells pretreated with IFN-alpha and IFN-beta. Immunofluorescence studies revealed inhibition of expression of the immediate early alpha-protein ICP 4. Induction of DNA-polymerase, a viral beta-protein, was inhibited both by IFN-alpha and IFN-beta in a dose-dependent manner. As suggested by SDS-polyacrylamide gel electrophoresis, other viral beta- and gamma-proteins of HSV were inhibited by IFN-alpha and IFN-beta as well.