In vitro induction of human cell-mediated cytotoxicity directed against herpes simplex virus-infected cells. Kinetics in normal donors and patients with recurrent herpes labialis.

In order to analyse cellular cytotoxic mechanisms involved in herpes virus infections, human peripheral blood mononuclear leukocytes (PBML) were incubated (sensitized) for up to 7 days with uninfected or herpes simplex virus type 1 (HSV-1)-infected cells. The sensitized PBML were then tested in a 5-hr 51Cr-release microassay against uninfected, HSV-1-infected, or cytomegalovirus (CMV)-infected target cells. PBML from normal donors, sensitized with HSV-1 infected cells, exhibited strong cytotoxicity against these same cells, but not against CMV-infected target cells. Peak cytotoxic activity was found after 6 days of sensitization. In contrast, PBML from herpes patients showed an earlier (3 days) and a higher cytotoxic response than normal PBML. In both groups however, maximal stimulation of lymphocyte transformation was observed at 6 days, suggesting that the early cytotoxic response in herpes patients could be an in vitro correlate of an anamnestic, or secondary response.