The Wellcome Foundation lecture, 1986. The molecular control of normal and leukaemic granulocytes and macrophages.

The development of semisolid culture methods supporting the clonal proliferation and maturation of granulocytes and macrophages led to the discovery of a group of specific glycoproteins, the colony-stimulating factors (CSFs), whose function it is to control the proliferation and functional activity of granulocytes, macrophages and associated blood cells. The four known CSFs in the mouse and man have been purified and complementary DNAs (cDNAs) for each have been cloned. The injection of bacterially synthesized recombinant CSF into mice has demonstrated that these CSFs can function in vivo to regulate granulocyte and macrophage formation. A major physiological role played by these CSFs is to control resistance to invading microorganisms through mechanisms capable of extremely rapid activation. Because the CSFs are the only known proliferative factors for these cells, the CSFs are involved in the initiation and the emergence of myeloid leukaemia but, conversely, at least one of the CSFs, G-CSF, is able to suppress myeloid leukaemic populations because of the ability of the CSFs to initiate differentiation commitment in responding granulocytic and macrophage populations. The CSFs are promising agents for clinical use in the treatment of infections in patients with depressed granulocyte-macrophage formation and possibly in the management of some types of myeloid leukaemia.