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

Interleukin-2 (IL-2) production was stimulated with staphylococcus enterotoxin A, heatkilled 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 ≥ 100 IU/ml of human-α (HuIFN-α) or interferon-β (HuIFN-β), or with ≥ 10 IU/ml HuIFN-γ 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.