title: Prevention of intestinal allergy in mice by rflaA:Ova is associated with enforced antigen processing and TLR5-dependent IL-10 secretion by mDC.
abstract: Conjugated vaccines consisting of flagellin and antigen activate TLR5 and induce strong innate and adaptive immune responses. Objective of the present study was to gain further insight into the mechanisms by which flagellin fusion proteins mediate their immune modulating effects. In a mouse model of Ova-induced intestinal allergy a fusion protein of flagellin and Ova (rflaA:Ova) was used for intranasal and intraperitoneal vaccination. Aggregation status of flaA, Ova and flaA:Ova were compared by light scattering, uptake of fluorescence labeled proteins into mDC was analyzed, processing was investigated by microsomal digestion experiments. Mechanism of DC-activation was investigated using proteasome and inflammasome inhibitors. Immune responses of wildtype, IL-10(-/-), TLR5(-/-) mDCs and Ova-transgenic T cells were investigated. Mucosal and i.p.-application of rflaA:Ova were able to prevent allergic sensitization, suppress disease-related symptoms, prevent body weight loss and reduction in food uptake. Intranasal vaccination resulted in strongest suppression of Ova-specific IgE production. These protective effects were associated with increased aggregation of rflaA:Ova and accompanied by tenfold higher uptake rates into mDC compared to the mixture of both proteins. Microsomal digestion showed that stimulation with rflaA:Ova resulted in faster degradation and the generation of different peptides compared to rOva. rflaA:Ova-mediated activation of mDC could be suppressed in a dose-dependent manner by the application of both inflammasome and proteasome inhibitors. Using TLR5(-/-) mDC the rflaA:Ova induced IL-10 secretion was shown to be TLR5 dependent. In co-cultures of IL-10(-/-) mDC with DO11.10 T cells the lack of rflaA:Ova-mediated IL-10 secretion resulted in enhanced levels of both TH2 (IL-4, IL-5) and TH1 (IL-2 and IFN-y) cytokines. In summary, mucosal vaccination with flaA:Ova showed strongest preventive effect. Stimulation with rflaA:Ova results in strong immune modulation mediated by enhanced uptake of the aggregated fusion protein, likely resulting in a different processing by DC as well as stronger TLR5 mediated cell activation.
authors: Division of Allergology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Stefan
authors: S
authors: Schülke
authors: Division of Allergology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Sonja
authors: S
authors: Wolfheimer
authors: Christian Doppler Laboratory for Allergy Diagnosis and Therapy, Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors: Gabriele
authors: G
authors: Gadermaier
authors: Division of Allergology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Andrea
authors: A
authors: Wangorsch
authors: Junior Research Group "Experimental Allergy Models", Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Susanne
authors: S
authors: Siebeneicher
authors: Christian Doppler Laboratory for Allergy Diagnosis and Therapy, Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors: Peter
authors: P
authors: Briza
authors: Division of Microbiology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Ingo
authors: I
authors: Spreitzer
authors: Division of Allergology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Dirk
authors: D
authors: Schiller
authors: Division of Microbiology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Bettina
authors: B
authors: Loeschner
authors: Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Osaka, Osaka Prefecture, Japan.
authors: Satoshi
authors: S
authors: Uematsu
authors: CNRS Department of Molecular and Experimental Immunology and Neurogenetics, Allergy and Lung Inflammation, University of Orléans, Orléans, Loiret département, France.
authors: Bernard
authors: B
authors: Ryffel
authors: Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Osaka, Osaka Prefecture, Japan.
authors: Shizuo
authors: S
authors: Akira
authors: Junior Research Group "Novel vaccination strategies and early immune responses", Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Zoe
authors: Z
authors: Waibler
authors: Division of Allergology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Stefan
authors: S
authors: Vieths
authors: Junior Research Group "Experimental Allergy Models", Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Masako
authors: M
authors: Toda
authors: Division of Allergology, Paul-Ehrlich-Institut, Langen, Hessen, Germany.
authors: Stephan
authors: S
authors: Scheurer
mesh_terms: D056704:Adaptive Immunity / Q000276:immunology; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D004195:Disease Models, Animal; D006967:Hypersensitivity / Q000517:prevention & control*; D016753:Interleukin-10 / Q000276:immunology*; D007422:Intestines / Q000276:immunology*; D051379:Mice; D051198:Toll-Like Receptor 5 / Q000276:immunology*; D014611:Vaccination / Q000379:methods*
chemical_list: D051198:Toll-Like Receptor 5; D016753:Interleukin-10