ABSTRACT
A number of important functions have been ascribed to interleukin-2 (IL-2). Human recombinant IL-2 (rIL-2) administered to mice induced the proliferation and activation of natural killer (NK) cells and hematopoietic cells, including both myeloid and erythroid cells. The administration of rIL-2 to experimental animals has proved effective in increasing resistance against various infectious agents, including certain specific bacterial, viral, and parasitic agents. An important observation was that splenic cells enriched in T cells, but not serum, from immune mice transferred resistance in murine cryptococcal infections. The appreciation of a possible role for rIL-2 in the treatment of life-threatening infections in man was part of the rationale for exploring the effects of the lymphokine in patients with the acquired immunodeficiency syndrome. The role of rIL-2 on NK cell activity and survival in cryptococcal-infected mice was determined in three separate experiments.
