RECEPTOR ROLE OF MEMBRANE-BOUND MACROPHAGE-COLONY-STIMULATING FACTOR

According to the definition of cytokine, the direction of signaling sh ould be from cytokine to receptor. The counter receptor was presented. Membrane bound macrophage colony-stimulating factor (m-M-CSF) and its receptor (M-CSF-R) were shown in human leukemic cell line J6-1 as aut ojuxtacrine mechanism. Soluble M-CSF receptor (sM-CSF-R), which was is olated from J6-1 cells membrane, was added into J6-1 cell culture. It was observed inhibition of J6-1 cell proliferation, decreasing of mito sis index and ratio of multinuclear cells, enlargement of cell diamete r and volume, down regulation of numerous surface antigens. Dramatic c hange of intracellular pH was shown between several min to 20 min afte r treatment of sM-CSF-R. It suggested that some information was transm itted via m-M-CSF from sM-CSF-R. This counter signaling was not influe nced by saccharification of m-M-CSF.