Cell-mediated cytotoxicity to herpes-infected cells in humans: dependence on antibodies

Herpes simplex virus type 1 (HSV-1)-infected human skin fibroblasts were used as target cells in a 51Cr release assay, using peripheral blood mononuclear cells from HSV-seropositive and -seronegative donors as effector cells. Cytotoxicity was exerted by ordinarily prepared lymphoid cells but could be reduced by extensive washing of the effector cells. The antibody dependence of the system was shown by the recovery of activity through addition of positive serum or medium used for the early washes of effector cells. Three donors found to be seronegative in the usual serological tests were shown to be seropositive in this test. It is proposed that the assay can be used as a very sensitive serological test.