Effects of Interferons-α, -β, and -γ on Human Interleukin-2 Production

Interleukin-2 (IL-2) production was stimulated with staphylococcus enterotoxin A, heat-killed Staphylococcus aureus, or concanavalin A (ConA) in cultures of human peripheral blood mononuclear cells (PBMC). IL-2 was characterized by its effect on IL-2-dependent cytotoxic T lymphocytes (CTLL cells) and mouse thymocytes. Pretreatment of PBMC with greater than or equal to 100 IU/ml of human-alpha (HuIFN-alpha) or interferon-beta (HuIFN-beta), or with greater than or equal to 10 IU/ml HuIFN-gamma for 4 h enhanced the IL-2 production. The effects of 20-h IFN treatments were less pronounced or they exerted an inhibitory effect. Our results indicate that IFNs modulate IL-2 production, which in turn can mediate some of the immunomodulatory effects of IFNs.