Interleukin 2 down-modulates the macrophage colony-stimulating factor receptor in murine macrophages.
Macrophage colony-stimulating factor (M-CSF) is the main growth factor for mononuclear phagocytes. Responsiveness to growth factors is reduced in the course of functional activation of macrophages. We studied the interference of the macrophage activator interleukin 2 (IL-2) with the response to M-CSF, in macrophages of the M-CSF-dependent murine line BAC-1.2F5. Long-term effects of IL-2 on cell growth were determined, showing that IL-2 reduces the M-CSF-dependent proliferation of macrophages. Short-term effects of IL-2 on the expression of the receptor for M-CSF (M-CSF.R) were characterized in more detail. IL-2 rapidly down-modulated M-CSF.R in a dose-dependent fashion, and interferon-gamma and lipopolysaccharides synergized with IL-2 in this modulation. The IL-2-induced down-modulation of M-CSF.R was shown to require the activity of protein-kinase-C and phospholipase-C. The data are consistent with the hypothesis that the down-modulation of M-CSF.R is a general property of macrophage activators.
Dello Sbarba
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Istituto di Patologia Generale della Università degli Studi di Firenze, Florence, Italy.
Nencioni
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L
Labardi
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Rovida
E
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Caciagli
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B
Cipolleschi
M G
MG
D000818:Animals; D015536:Down-Regulation / Q000187:drug effects*; D004357:Drug Synergism; D007371:Interferon-gamma / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D011493:Protein Kinase C / Q000378:metabolism; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism
D007376:Interleukin-2; D008070:Lipopolysaccharides; D007371:Interferon-gamma; D016186:Receptor, Macrophage Colony-Stimulating Factor; D011493:Protein Kinase C; D010738:Type C Phospholipases