Herpes simplex virus as an inducer of interferon in human monocyte cultures

Induction of alpha interferon in human monocyte cultures exposed to moderate titres of herpes simplex virus (HSV) is a regular phenomenon, but shows variability in the resulting interferon titres. Thirty recent clinical isolates of HSV (15 type 1 and 15 type 2) were found to be equally effective interferon inducers, irrespective of their origin. Ultraviolet irradiation or thermal inactivation of the virus or blocking of the DNA synthesis by foscarnet did not destroy the capability of the virus to induce interferon. These results show that the interferon response in HSV-exposed human monocytes is relatively independent from the inducing virus strain and does not require replication of HSV.