Role of GM-CSF in phagocyte recruitment and regulation of c-fos protooncogene expression.

Recombinant GM-CSF induced migration across polycarbonate filters of monocytes and polymorphonuclear leukocytes. Checkerboard analysis revealed that induction of phagocyte migration involved actual chemotaxis. Hence GM-CSF, released by activated endothelium and leukocytes, may play a role in phagocyte recruitment to amplify resistance against noxious agents. Activation of leukocytes by GM-CSF was associated with early, transient augmentation of the expression of the c-fos protooncogene. c-fos expression may be associated with functional reprogramming of phagocytes by this cytokine.