Reactivation of herpes simplex virus is associated with production of a low molecular weight factor that inhibits lymphokine activity in vitro.

Peripheral blood mononuclear cells obtained during recrudescent Herpes simplex virus (HSV) infection and stimulated with UV-inactivated viral antigen (UV-HSV) for 24 hr produced a low molecular weight (dialyzable) factor that inhibited lymphokine activity. This factor prevented the expression of leukocyte inhibitory factor (LIF) activity, but not its production. It was not made in UV-HSV-stimulated cultures grown in presence of 2 X 10(-6) M indomethacin nor in cultures of peripheral blood mononuclear cells obtained during convalescence or quiescence (greater than 4 days from onset of clinical symptoms) or from seropositive controls without a history of recurrent HSV disease. Dialyzable inhibitory factor production required OKM1+, OKT8+, and OKIa+ cells as determined by complement-mediated lysis with monoclonal antibody. Dialyzable inhibitory factor activity was associated with a trypsin-sensitive 8.2 K fraction as determined by Sephadex chromatography followed by sodium dodecyl sulfate-acrylamide gel electrophoresis.