[Interleukins: factors of intercellular communication].

Immune response implies reactions between immunocompetent cells. These reactions are made by direct contact between cells and via soluble factors. Among the latter, the interleukins, protein molecules produced during antigenic and mitogenic stimulation by the immunocompetent cells, intervene as modulators of the immune response. Interleukin-1, a protein synthesized by the activated macrophages, participates in the induction of interleukin-2 production by stimulated T-lymphocytes. Interleukin-2, a glycoprotein molecule, is the growth factor of activated T-lymphocytes by enabling their proliferation and clonal propagation. Interleukin-3, or Multi-colony stimulating factor, controls the production and the differentiation of haemopoietic cells and thus probably plays an important role in resistance to infections.