title: IL-12 synergizes with IL-2 and other stimuli in inducing IL-10 production by human T cells.
abstract: IL-12, a potent inducer of IFN-gamma production by T cells and NK cells, has been recently reported to exacerbate an established Th2 response in vivo. However, the effect of IL-12 on Th2-lymphokine production remains unclear. Since IL-10 is a lymphokine associated with Th2 responses which decreases both IL-12-induced IFN-gamma production and IL-12 production by macrophages, we have analyzed here, in an APC-free system, the ability of IL-12 to modulate the production of human IL-10 by established Th0, Th1, and Th2 T cell clones (TCC), T cell lines, and purified peripheral blood T cells. IL-12 synergized with anti-CD3 mAb, Con A, or IL-2 in inducing IL-10 production by Th0, Th1, and Th2 TCC and by T cell lines. This effect was dose dependent (from 0.1 to 50 U/ml) and associated with an increase of IL-10 mRNA transcription. As previously reported, IL-12 also enhanced IFN-gamma production by stimulated Th1 and Th0 TCC and, to a lesser extent, IL-4 production by stimulated Th0 and Th2 TCC. These observations were extended to peripheral blood T cells stimulated in the presence of exogenous IL-2. Moreover, using neutralizing anti-IL-2 Ab, we report that endogenous IL-2 produced by stimulated Th0 TCC could in part contribute to the effect of IL-12 on IL-10 and IL-4 production. In conclusion, IL-12 synergizes with IL-2 and other stimuli in inducing IL-4 and IL-10 production by T cells. This property may help to explain why IL-12 does not efficiently down-regulate an established Th2 response.
authors.affiliation: Glaxo Institute for Molecular Biology, Department of Immunology, Geneva, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Jeannin
authors.forename: Y
authors.initials: Y
authors.lastname: Delneste
authors.forename: M
authors.initials: M
authors.lastname: Seveso
authors.forename: P
authors.initials: P
authors.lastname: Life
authors.forename: J Y
authors.initials: JY
authors.lastname: Bonnefoy
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001483:Base Sequence; D017252:CD3 Complex / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D002999:Clone Cells / Q000378:metabolism; D004357:Drug Synergism; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis*; D018664:Interleukin-12 / Q000494:pharmacology* / Q000502:physiology; D007376:Interleukin-2 / Q000494:pharmacology*; D015847:Interleukin-4 / Q000096:biosynthesis; D007399:Interphase / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D000276:Adjuvants, Immunologic; D000911:Antibodies, Monoclonal; D017252:CD3 Complex; D007376:Interleukin-2; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4