title: IL-10- and IL-12-independent down-regulation of allergic sensitization by stimulation of CD40 signaling.
abstract: Interaction between CD154 (CD40 ligand) on activated T lymphocytes and its receptor CD40 has been shown to be critically involved in the generation of cell-mediated as well as humoral immunity. CD40 triggering activates dendritic cells (DC), enhances their cytokine production, up-regulates the expression of costimulatory molecules, and induces their maturation. It is unknown how stimulation of CD40 during sensitization to an airborne allergen may affect the outcome of allergic airway inflammation. We took advantage of a mouse model of allergic asthma and a stimulatory mAb to CD40 (FGK45) to study the effects of CD40-mediated DC activation on sensitization to OVA and subsequent development of OVA-induced airway inflammation. Agonistic anti-CD40 mAb (FGK45) injected during sensitization with OVA abrogated the development of allergic airway inflammation upon repeated airway challenges with OVA. Inhibition of bronchial eosinophilia corresponded with reduced Th2 cytokine production and was independent of IL-12, as evidenced by a similar down-regulatory effect of anti-CD40 mAb in IL-12 p40-deficient mice. In addition, FGK45 equally down-regulated allergic airway inflammation in IL-10-deficient mice, indicating an IL-10-independent mechanism of action of FGK45. In conclusion, our results show that CD40 signaling during sensitization shifts the immune response away from Th2 cytokine production and suppresses allergic airway inflammation in an IL-12- and IL-10-independent way, presumably resulting from enhanced DC activation during sensitization.
authors.affiliation: Laboratory of Experimental Immunology, University Hospitals, Faculty of Medicine, Katholieke Universiteit Leuven, Leuven, Belgium. Peter.Hellings@med.kuleuven.be
authors.forename: Peter W
authors.initials: PW
authors.lastname: Hellings
authors.forename: Ahmad
authors.initials: A
authors.lastname: Kasran
authors.forename: Dominique
authors.initials: D
authors.lastname: Bullens
authors.forename: Lutgart
authors.initials: L
authors.lastname: Overbergh
authors.forename: Chantal
authors.initials: C
authors.lastname: Mathieu
authors.forename: Hubertine
authors.initials: H
authors.lastname: Heremans
authors.forename: Patrick
authors.initials: P
authors.lastname: Matthys
authors.forename: Louis
authors.initials: L
authors.lastname: Boon
authors.forename: Mark
authors.initials: M
authors.lastname: Jorissen
authors.forename: Jan L
authors.initials: JL
authors.lastname: Ceuppens
mesh_terms: D000818:Animals; D019013:CD40 Antigens / Q000276:immunology / Q000378:metabolism*; D016207:Cytokines / Q000096:biosynthesis; D015536:Down-Regulation / Q000276:immunology*; D006967:Hypersensitivity / Q000276:immunology*; D007109:Immunity; D007114:Immunization; D007249:Inflammation; D016753:Interleukin-10 / Q000502:physiology*; D018664:Interleukin-12 / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D015398:Signal Transduction / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D019013:CD40 Antigens; D016207:Cytokines; D016753:Interleukin-10; D018664:Interleukin-12