Chemotactic activity of human recombinant granulocyte-macrophage colony-stimulating factor.

Recombinant human granulocyte-macrophage colony-stimulating factor seeded in the lower compartment of chemotaxis chambers induced migration of human peripheral blood monocytes and polymorphonuclear phagocytes and elicited an actual chemotactic response inphagocytes.

Abstract

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) seeded in the lower compartment of chemotaxis chambers induced migration of human peripheral blood monocytes and polymorphonuclear phagocytes. rhGM-CSF was active in inducing phagocyte migration at concentrations as low as 10 CML units/ml (corresponding to 0.002 microgram), and maximal activity was observed at 10(2)-10(4)/ml. Checkerboard analysis performed by seeding different concentrations of rhGM-CSF above and below the filter revealed that maximal induction of migration required a positive concentration gradient between the lower and upper compartment, and that rhGM-CSF elicited an actual chemotactic response in phagocytes. Human umbilical vein endothelial cells and blood large granular lymphocytes (LGL) responded poorly or not at all (endothelial cells) to rhGM-CSF under conditions in which appropriate reference chemoattractants were active. The chemotactic activity of rhGM-CSF may serve to recruit phagocytic cells from the blood compartment to amplify resistance against noxious agents.