[Interleukine-3: a multifunctional cytokine].

Normal hematopoiesis is regulated in part by a variety of growth factors (HGF) acting at different stages of cellular maturation. Among the HGF acting on early progenitors, Interleukin-3 (IL-3) is one of the first well characterized. This cytokine exhibits various biological activities including proliferative effects on hematopoietic stem cells as well as regulatory properties on mature elements involved in inflammation and late hypersensitivity. Therapeutical use of IL-3 has been suggested in various situations involving bone marrow abnormalities, chemotherapy during acute leukemias or HIV infections, and bone marrow transplantation. Nevertheless, present data concerning such therapeutic studies involving IL-3 alone are deceptive. Thus, current investigations are conducted to investigate the potential therapeutic effects of HGF combinations that include IL-3, of or fusion proteins such as IL-3/GM-CSF or IL-3/Epo hybrid molecules.