Recombinant and native human urinary colony-stimulating factor directly augments granulocytic and granulocyte-macrophage colony-stimulating factor production of human peripheral blood monocytes.

Colony-stimulating factor from human urine (CSF-HU) has been purified to a homogeneous protein, and its complementary DNA (cDNA) has been cloned. Recombinant CSF-HU was prepared from a serum-free medium conditioned by Chinese hamster ovary cells transfected with the cDNA and purified by the same method as that for the native protein. Purified CSF-HU stimulated human bone marrow cells to form macrophage colonies. It also stimulated human mature monocytes prepared from peripheral blood of healthy volunteers to produce human active colony-stimulating activity that stimulates human bone marrow cells to form granulocyte and macrophage colonies. This activity was partially neutralized by the addition of both polyclonal antibodies against human granulocyte colony-stimulating factor and against human granulocyte-macrophage CSF, respectively. The stimulation of monocytes by CSF-HU was not inhibited by the addition of polymyxin-B, which is known as a potent inhibitor of endotoxin. On the other hand, CSF-HU did not stimulate monocyte production of interleukin-1 and interferon. These results indicate that recombinant and native CSF-HU stimulates immature cells as well as mature cells in the human monocyte lineage.