Macrophage colony-stimulating factor and granulocyte colony-stimulating factor separated from fibrosarcoma tissue in mice.

Large increases of granulocytes and monocytes were found in the blood of mice bearing fibrosarcoma. Extraction of the tumor tissue with isotonic saline yielded a colony-stimulating factor (CSF). Further extraction of the saline-insoluble materials with 0.1% sodium dodecyl sulfate afforded another pool of CSF. Incubation of the tumor cells in vitro resulted in the accumulation of CSF activity in the culture medium. The CSF from these sources produced both granulocyte colonies and macrophage colonies in murine bone marrow cell culture. Subsequently, the activity producing granulocyte colonies was separated from that producing macrophage colonies by isoelectrofocusing and repeated gel-filtration chromatography. It was also shown that anti-L cell CSF antiserum neutralized the macrophage CSF activity but not the granulocyte CSF activity. These results show that the granulocytosis-inducing tumor produces two types of CSF.