title: Protein unfolding strongly modulates the allergenicity and immunogenicity of Pru p 3, the major peach allergen.
abstract: BACKGROUND
  Allergen-specific immunotherapy for food allergies, including peach allergy, has not been established. Use of allergens with reduced allergenic potential and preserved immunogenicity could improve the safety and efficacy of allergen-specific immunotherapy.
  
  
  OBJECTIVE
  We sought to create a hypoallergenic derivative of the major peach allergen Pru p 3 and to characterize its biochemical and immunologic properties.
  
  
  METHODS
  A Pru p 3 folding variant generated by means of reduction and alkylation was investigated for structural integrity and stability to gastrointestinal enzymes. IgE reactivity and allergenic potency were determined by means of immunoblotting, ELISA, and in vitro mediator release assay with sera from patients with peach allergy. T-cell immunogenicity was investigated by using human allergen-specific T cells and CBA/J mice immunized with either native Pru p 3 (nPru p 3) or reduced and alkylated (R/A) Pru p 3. Pru p 3 processing by endolysosomal fractions of dendritic cells and antigenicity was examined in mice.
  
  
  RESULTS
  Unfolding of Pru p 3 reduced its high resistance to gastrointestinal proteolysis and almost completely abrogated its IgE reactivity and allergenic potency. However, R/A Pru p 3 was capable of stimulating human and murine T cells. Endolysosomal degradation of R/A Pru p 3 was accelerated in comparison with nPru p 3, but similar peptides were generated. IgG and IgE antibodies raised against nPru p 3 showed almost no cross-reactivity with R/A Pru p 3. Moreover, the antigenicity of R/A Pru p 3 was strongly reduced.
  
  
  CONCLUSIONS
  Unfolded Pru p 3 showed reduced allergenicity and antigenicity and preserved T-cell immunogenicity. The hypoallergenic variant of Pru p 3 could be a promising vaccine candidate for specific immunotherapy of peach allergy.
authors.affiliation: Junior Research Group Experimental Allergy Models, Paul-Ehrlich-Institut, Langen, Germany. todma@pei.de
authors.forename: Masako
authors.initials: M
authors.lastname: Toda
authors.forename: Gerald
authors.initials: G
authors.lastname: Reese
authors.forename: Gabriele
authors.initials: G
authors.lastname: Gadermaier
authors.forename: Veronique
authors.initials: V
authors.lastname: Schulten
authors.forename: Iris
authors.initials: I
authors.lastname: Lauer
authors.forename: Matthias
authors.initials: M
authors.lastname: Egger
authors.forename: Peter
authors.initials: P
authors.lastname: Briza
authors.forename: Stefanie
authors.initials: S
authors.lastname: Randow
authors.forename: Sonja
authors.initials: S
authors.lastname: Wolfheimer
authors.forename: Valencia
authors.initials: V
authors.lastname: Kigongo
authors.forename: Maria
authors.initials: M
authors.lastname: Del Mar San Miguel Moncin
authors.forename: Kay
authors.initials: K
authors.lastname: Fötisch
authors.forename: Barbara
authors.initials: B
authors.lastname: Bohle
authors.forename: Stefan
authors.initials: S
authors.lastname: Vieths
authors.forename: Stephan
authors.initials: S
authors.lastname: Scheurer
mesh_terms: D000485:Allergens / Q000737:chemistry* / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant; D003888:Desensitization, Immunologic / Q000379:methods; D005512:Food Hypersensitivity / Q000276:immunology* / Q000517:prevention & control; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008808:Mice, Inbred CBA; D010940:Plant Proteins; D017433:Protein Structure, Secondary; D058767:Protein Unfolding; D027861:Prunus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; C463181:Pru p 3 allergen