Lymphocyte transformation and interferon production in human mononuclear cell microcultures for assay of cellular immunity to herpes simplex virus.
Interferon production and transformation in response to herpes simplex virus antigen were studied in microcultures of human mononuclear cells. Mononuclear cells consisting of monocytes and both T and B lymphocytes were purified by Ficoll-Hypaque gradients. Lymphocytes, predominantly T with 5% B, were obtained by passage of buffy-coat cells through nylon fiber columns. For some experiments, autochthonous macrophages and column-purified lymphocytes were stimulated with herpesvirus antigen. The effect of specific antibody and cell concentration on reactivity is described. Crude and purified antigens were compared as cell culture stimulants. Significant differences in transformation and interferon were observed between donors with a history of herpes labialis and donors with no detectable antibody, both in cultures prepared by Ficoll-Hypaque gradients and by column purification of lymphocytes. Cultures from seronegative donors prepared by Ficoll-Hypaque gradients produced interferon but did not transform when stimulated by herpes simplex antigen. "Immune" interferon production, that is, type II as opposed to type I, occurred only with autochthonous macrophage and column-purified lymphocyte cultures. Interferon produced by Ficoll-Hypaque-purified mononuclear cultures was type I, and its production was unrelated to immune status. Similarly, column-purified lymphocytes responded to herpes simplex virus antigen with type I interferon if obtained from a seropositive donor.