Further studies on the regulation of lymphokine biosynthesis in contact sensitivity

Contact sensitivity (CS) results from a series of cellular interactions involving CD4+ T cells and macrophages. We have studied the production of lymphokines by T cells from mice immunized by contact sensitization and by a variety of stimuli leading to CS or tolerance to CS. Primed T cells from mice immunized for CS are predominantly of the TH1 type. Conversely, a failure in the activation of these antigen-specific TH1 cells is a key step in the induction of tolerance to CS. Spleen cells from tolerant mice can suppress the production of lymphokines from primed cells, both in an adoptive transfer system and when mixed with effector cells in vitro. The relative importance of lymphokine competition, prostaglandin production by adherent cells, and other mechanisms underlying this suppression is discussed.