[Cytokines and hematopoiesis].

The identification and purification of haemopoietic growth regulators have resulted in a better understanding of control mechanisms. Cloning and expression of the corresponding genes have shown that most of the activities observed correspond to specific glycoproteins produced by cells from numerous tissues, including those of bone marrow stroma and immune system. These cytokines activate the responsive cells through specific receptors expressed on their membranes. They exert an accurate control of haematopoiesis in a network of synergistic and antagonistic factors. The exact identification of their biological activities, together with the possibility of producing them in large amounts by genetic recombination, have already resulted in their therapeutic use with, in certain cases, a remarkable efficiency.