title: Dual role of the IL-12/IFN-gamma axis in the development of autoimmune myocarditis: induction by IL-12 and protection by IFN-gamma.
abstract: IL-12 and IFN-gamma positively regulate each other and type 1 inflammatory responses, which are believed to cause tissue damage in autoimmune diseases. We investigated the role of the IL-12/IFN-gamma (Th1) axis in the development of autoimmune myocarditis. IL-12p40-deficient mice on a susceptible background resisted myocarditis. In the absence of IL-12, autospecific CD4(+) T cells proliferated poorly and showed increased Th2 cytokine responses. However, IFN-gamma-deficient mice developed fatal autoimmune disease, and blockade of IL-4R signaling did not confer susceptibility to myocarditis in IL-12p40-deficient mice, demonstrating that IL-12 triggers autoimmunity by a mechanism independent of the effector cytokines IFN-gamma and IL-4. In conclusion, our results suggest that the IL-12/IFN-gamma axis is a double-edged sword for the development of autoimmune myocarditis. Although IL-12 mediates disease by induction/expansion of Th1-type cells, IFN-gamma production from these cells limits disease progression.
authors.affiliation: Medicine A, University Hospital, and Basel Institute for Immunology, Basel, Switzerland. ueriksson@uhbs.ch
authors.forename: U
authors.initials: U
authors.lastname: Eriksson
authors.forename: M O
authors.initials: MO
authors.lastname: Kurrer
authors.forename: W
authors.initials: W
authors.lastname: Sebald
authors.forename: F
authors.initials: F
authors.lastname: Brombacher
authors.forename: M
authors.initials: M
authors.lastname: Kopf
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001327:Autoimmune Diseases / Q000209:etiology* / Q000517:prevention & control; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D007371:Interferon-gamma / Q000502:physiology*; D018664:Interleukin-12 / Q000502:physiology*; D015847:Interleukin-4 / Q000502:physiology; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009205:Myocarditis / Q000209:etiology* / Q000517:prevention & control; D018418:Th2 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
chemical_list: D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma