Lymphocyte stimulation by herpes simplex virus (HSV) antigens. 1. Culture conditions, cell fractionation and presentation of HSV antigens.

Optimal culture conditions for rabbit lymphocytes were established. Inclusion of 2-mercaptoethanol in the medium greatly enhanced responses. Lymphocytes from the blood of HSV-immunized rabbits responded specifically in vitro to heat-killed (56 degree, 60 min) or UV-inactivated HSV preparations. A UV dose of 13,392 ergs/mm2 was the most suitable inactivating dose. Oral intramucosal injection was the most effective way of generating blood lymphocyte responses to HSV, but animals immunized in tradermally or in tramuscularly with HSV in Freund's adjuvant also produced antigen-reactive cells after five or more immunizations. There were differences in the shape of the dose-response curves to various HSV1 mutants which were probably due to differences in the production of "stimulatory" and inhibitory antigens. Appreciable lymphocyte stimulation could be obtained with tissue culture fluid and enveloped virus antigens. Lymphocytes from HSV1-immune animals were also responsive to HSV2 antigens.