title: Toll-like receptor 4-mediated innate IL-10 activates antigen-specific regulatory T cells and confers resistance to Bordetella pertussis by inhibiting inflammatory pathology.
abstract: Signaling through Toll-like receptors (TLR) activates dendritic cell (DC) maturation and IL-12 production, which directs the induction of Th1 cells. We found that the production of IL-10, in addition to inflammatory cytokines and chemokines, was significantly reduced in DCs from TLR4-defective C3H/HeJ mice in response to Bordetella pertussis. TLR4 was also required for B. pertussis LPS-induced maturation of DCs, but other B. pertussis components stimulated DC maturation independently of TLR4. The course of B. pertussis infection was more severe in C3H/HeJ than in C3H/HeN mice. Surprisingly, Ab- and Ag-specific IFN-gamma responses were enhanced at the peak of infection, whereas Ag-specific IL-10-producing T cells were significantly reduced in C3H/HeJ mice. This was associated with enhanced inflammatory cytokine production, cellular infiltration, and severe pathological changes in the lungs of TLR4-defective mice. Our findings suggest that TLR-4 signaling activates innate IL-10 production in response to B. pertussis, which both directly, and by promoting the induction of IL-10-secreting type 1 regulatory T cells, may inhibit Th1 responses and limit inflammatory pathology in the lungs during infection with B. pertussis.
authors.affiliation: Immune Regulation Research Group, Department of Biochemistry, Trinity College, Dublin 2, Ireland.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Higgins
authors.forename: Ed C
authors.initials: EC
authors.lastname: Lavelle
authors.forename: Chantelle
authors.initials: C
authors.lastname: McCann
authors.forename: Brian
authors.initials: B
authors.lastname: Keogh
authors.forename: Edel
authors.initials: E
authors.lastname: McNeela
authors.forename: Patricia
authors.initials: P
authors.lastname: Byrne
authors.forename: Brian
authors.initials: B
authors.lastname: O'Gorman
authors.forename: Andrew
authors.initials: A
authors.lastname: Jarnicki
authors.forename: Peter
authors.initials: P
authors.lastname: McGuirk
authors.forename: Kingston H G
authors.initials: KH
authors.lastname: Mills
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001885:Bordetella Infections / Q000235:genetics / Q000276:immunology* / Q000473:pathology* / Q000517:prevention & control; D001886:Bordetella pertussis / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D002460:Cell Line; D018925:Chemokines / Q000096:biosynthesis; D002999:Clone Cells; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D015536:Down-Regulation / Q000235:genetics / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D007113:Immunity, Innate / Q000235:genetics; D018836:Inflammation Mediators / Q000378:metabolism / Q000502:physiology*; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000502:physiology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D011956:Receptors, Cell Surface / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000382:microbiology; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D015854:Up-Regulation / Q000235:genetics / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D018925:Chemokines; D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D016753:Interleukin-10; D007371:Interferon-gamma