EFFECTS OF MACROPHAGE-COLONY-STIMULATING FACTOR ON HUMAN MONOCYTES - INDUCTION OF EXPRESSION OF UROKINASE-TYPE PLASMINOGEN-ACTIVATOR, BUT NOT OF SECRETED PROSTAGLANDIN-E2, INTERLEUKIN-6, INTERLEUKIN-1, OR TUMOR-NECROSIS-FACTOR-ALPHA

It is often assumed that macrophage-colony stimulating factor (M-CSF) or CSF-1, as well as granulocyte macrophage-CSF (GM-CSF). can induce inflammatory mediator production by monocytes/macrophages. We demonstrate with elutriation-purified human monocytes that, in contrast to lipopolysaccharide, recombinant human CSF-1 does not induce secretion of prostaglandin E2, interleukin-6 (IL-6), IL-1beta, or tumor necrosis factor alpha, as measured by immunoassay; however, increased urokinase-type plasminogen activator (u-PA) activity in cell lysates and mRNA was observed. Similar results were obtained when the monocytes were treated with recombinant human GM-CSF. Such increased u-PA expression may contribute to the function of CSF-1 at sites of inflammation.