Interleukin-13 regulates the phenotype and function of human monocytes.
The monocyte glycosylphosphatidylinositol (GPI)-linked protein CD14 serves as the receptor for lipopolysaccharide (LPS), and regulates monocyte-lymphocyte interactions. We investigated whether CD14 expression is regulated by interleukin (IL)-13, a member of the chromosome 5 cytokine family. IL-13 inhibited CD14 expression on human monocytes. CD14 down-regulation resulted in the inhibition of LPS-induced release of tumor necrosis factor alpha, and involved neither shedding nor activation of endogenous GPI-anchor-cleaving enzymes. The CD14/actin RNA ratio was decreased 7-fold in IL-13-treated monocytes. Our results suggest that IL-13 down-regulates CD14 by suppressing CD14 RNA expression. Down-regulation of CD14, the LPS receptor, may play a major role in the anti-inflammatory effects of IL-13.
Viale
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Molecular Immunoregulation Unit, DIBIT/San Raffaele Scientific Institute, Milan, Italy.
Vercelli
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D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D015214:Antigens, Differentiation, Myelomonocytic / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects; D006801:Humans; D018793:Interleukin-13 / Q000494:pharmacology / Q000502:physiology*; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018793:Interleukin-13; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha