title: Granulocyte/macrophage colony-stimulating factor inhibits IL-12 production of mouse Langerhans cells.
abstract: We investigated the capacity of mouse Langerhans cells (LC) to produce IL-12, a central cytokine in a Th1 type of immune responses. We prepared purified LC (>95%) from BALB/c mouse skin by the panning method using anti-I-Ad mAb. An ELISA showed that purified LC spontaneously produced IL-12 p40, and that its production was up-regulated following simultaneous stimulation with anti-CD40 mAb and IFN-gamma. Surprisingly, GM-CSF strikingly inhibited IL-12 p40 production by anti-CD40/IFN-gamma-stimulated LC (% inhibition = 97.0 +/- 0.9% at 1 ng/ml GM-CSF). Supernatants of 48-h cultured keratinocytes (KC) also caused the inhibition of LC IL-12 p40 secretion, and this effect was neutralized by anti-GM-CSF mAb. IL-1alpha (1 ng/ml)-stimulated KC produced much more GM-CSF than unstimulated KC (60.9 +/- 0.2 pg/ml vs 20.9 +/- 1.7 pg/ml), and IL-1alpha-stimulated KC supernatants strongly inhibited IL-12 p40 production by anti-CD40/IFN-gamma-stimulated LC (% inhibition = 89.4 +/- 1.4%). A bioassay using an IL-12-dependent T cell line demonstrated the correlation of the level of IL-12 p40 with the bioactivity of IL-12. These results provide important implications for the pathogenesis of atopic dermatitis, which involves the participation of LC and KC with the capacity to produce IL-12 and GM-CSF, respectively.
authors.affiliation: Department of Dermatology, University of Tokyo, Tokyo, Japan. ytada-tky@umin.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Tada
authors.forename: A
authors.initials: A
authors.lastname: Asahina
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.forename: M
authors.initials: M
authors.lastname: Tomura
authors.forename: H
authors.initials: H
authors.lastname: Fujiwara
authors.forename: K
authors.initials: K
authors.lastname: Tamaki
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015703:Antigens, CD / Q000096:biosynthesis; D019013:CD40 Antigens / Q000276:immunology; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D015536:Down-Regulation / Q000276:immunology; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000502:physiology*; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007371:Interferon-gamma / Q000494:pharmacology; D018664:Interleukin-12 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D015603:Keratinocytes / Q000276:immunology / Q000378:metabolism; D007801:Langerhans Cells / Q000276:immunology* / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology / Q000276:immunology; D015854:Up-Regulation / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D019013:CD40 Antigens; D007166:Immunosuppressive Agents; D008562:Membrane Glycoproteins; D018664:Interleukin-12; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor