title: Type I IFN negatively regulates CD8+ T cell responses through IL-10-producing CD4+ T regulatory 1 cells.
abstract: Pleiotropic, immunomodulatory effects of type I IFN on T cell responses are emerging. We used vaccine-induced, antiviral CD8(+) T cell responses in IFN-beta (IFN-beta(-/-))- or type I IFN receptor (IFNAR(-/-))-deficient mice to study immunomodulating effects of type I IFN that are not complicated by the interference of a concomitant virus infection. Compared with normal B6 mice, IFNAR(-/-) or IFN-beta(-/-) mice have normal numbers of CD4(+) and CD8(+) T cells, and CD25(+)FoxP3(+) T regulatory (T(R)) cells in liver and spleen. Twice as many CD8(+) T cells specific for different class I-restricted epitopes develop in IFNAR(-/-) or IFN-beta(-/-) mice than in normal animals after peptide- or DNA-based vaccination. IFN-gamma and TNF-alpha production and clonal expansion of specific CD8(+) T cells from normal and knockout mice are similar. CD25(+)FoxP3(+) T(R) cells down-modulate vaccine-primed CD8(+) T cell responses in normal, IFNAR(-/-), or IFN-beta(-/-) mice to a comparable extent. Low IFN-alpha or IFN-beta doses (500-10(3) U/mouse) down-modulate CD8(+) T cells priming in vivo. IFNAR- and IFN-beta-deficient mice generate 2- to 3-fold lower numbers of IL-10-producing CD4(+) T cells after polyclonal or specific stimulation in vitro or in vivo. CD8(+) T cell responses are thus subjected to negative control by both CD25(+)FoxP3(+) T(R) cells and CD4(+)IL-10(+) T(R1) cells, but only development of the latter T(R) cells depends on type I IFN.
authors.affiliation: Department of Medical Microbiology and Immunology, University of Ulm, Helmholtzstrasse 8/1, D-89081 Ulm, Germany. nektarios.dikopoulos@medizin.uni-ulm.de
authors.forename: Nektarios
authors.initials: N
authors.lastname: Dikopoulos
authors.forename: Antonio
authors.initials: A
authors.lastname: Bertoletti
authors.forename: Andrea
authors.initials: A
authors.lastname: Kröger
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Hauser
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schirmbeck
authors.forename: Jörg
authors.initials: J
authors.lastname: Reimann
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D051858:Forkhead Transcription Factors; D007370:Interferon Type I / Q000276:immunology*; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000235:genetics / Q000276:immunology*; D008099:Liver / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout; D017471:Receptors, Interferon / Q000235:genetics; D015375:Receptors, Interleukin-2 / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D007370:Interferon Type I; D017471:Receptors, Interferon; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D007371:Interferon-gamma