Colony-stimulating factors and host defense.

Colony-stimulating factors are growth factors responsible for the proliferation and the maturation of bone marrow stem cells to fully differentiated granulocytes and monocytes. In addition to their effects on hematopoiesis, some colony-stimulating factors prime mature cells for enhanced chemotaxis, phagocytosis, and killing in response to physiologic stimuli. The action of colony-stimulating factors is mediated by growth factor receptors on precursor and mature effector cells. The results of studies of granulocyte-macrophage colony-stimulating factors in patients with the acquired immunodeficiency syndrome (AIDS) suggest a possible therapeutic role for colony-stimulating factors in augmenting mechanism of host defense.