MECHANISM OF INHIBITION OF HSV-1 REPLICATION BY TUMOR-NECROSIS-FACTOR AND INTERFERON-GAMMA

Tumor necrosis factor (TNF) synergizes with interferon (IFNγ) in the blockade of HSV-1 replication. Antibodies against IFNβ block this synergism, implying a role of IFNβ in the antiviral activity of TNF plus IFNγ. IFNβ1 added exogenously to Hep-2 cells shows antiviral activity against HSV-1 only at high concentrations, whereas IFNβ2 (also known as IL-6) alone has no effect on the replication of VSV or HSV-1 even when 1,000 U/ml are present. Our results are in accordance with the idea that TNF induces IFNβ1 and that both cytokines must be present in the culture medium to synergize with IFNγ in order to inhibit HSV-1 replication. © 1991.