Antigen-mediated interleukin production by mononuclear cells from delayed hypersensitive mice.

Antigen-induced production of interleukins was examined using lymph node cells from BALB/c mice immunized with soluble protein antigens emulsified in complete Freund's adjuvant. We found both Interleukin 1 and Interleukin 2 activity in the antigen-stimulated culture supernatants of lymph node cells obtained from mice immunized with the corresponding antigen. The induction of interleukins correlated with in vivo (footpad response) and in vitro (lymphocyte proliferation) manifestations of delayed hypersensitivity. The kinetics of appearance of IL 1 and IL 2 in culture was similar. Stimulation with unrelated antigens could induce neither interleukins nor both types of cell-mediated immune responses. These results demonstrate that interleukins are inducible by stimulation with soluble proteins under conditions of immunization that lead to cell-mediated immunity.