Interleukin-2, anti-interleukin-2 receptor antibody, and activation of macrophages.

Macrophages treated with IFN-gamma and IL-2 before exposure to parasites develop the ability to resist infection with amastigotes of Leishmania major. In this cooperative interaction of cytokines, IL-2 can be replaced with any of several mAb directed against the beta chain of the IL-2 receptor, but not by antibodies to a number of other cell receptors or antigens. Thus, antibodies to the IL-2 receptor act as agonists of IL-2 in the induction of a biologic activity in macrophages, and macrophages, a nonproliferating cell type, respond to signals transmitted through the beta chain of the IL-2 receptor.