Protein unfolding strongly modulates the allergenicity and immunogenicity of Pru p 3, the major peach allergen

• Published in: Journal of allergy and clinical immunology 2011-11, Vol.128 (5), p.1022-1030.e7
• Main Authors: Toda, Masako, PhD, Reese, Gerald, PhD, Gadermaier, Gabriele, PhD, Schulten, Veronique, MSc, Lauer, Iris, PhD, Egger, Matthias, PhD, Briza, Peter, PhD, Randow, Stefanie, Wolfheimer, Sonja, Kigongo, Valencia, BSc, del Mar San Miguel Moncin, Maria, MD, Fötisch, Kay, PhD, Bohle, Barbara, PhD, Vieths, Stefan, PhD, Scheurer, Stephan, PhD
• Format: Article
• Language: English
• Subjects: allergen-specific immunotherapy; Allergens - chemistry; Allergens - immunology; Allergies; Allergy and Immunology; Animals; antigenicity; Antigens, Plant; Biological and medical sciences; Cell growth; Chemical bonds; Desensitization, Immunologic - methods; Experiments; folding variant; Food; Food allergies; Food Hypersensitivity - immunology; Food Hypersensitivity - prevention & control; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; hypoallergen; Immunization; immunogenicity; Immunopathology; Immunotherapy; Lymphocyte Activation - immunology; Lymphocytes; Medical sciences; Mice; Mice, Inbred CBA; nonspecific lipid transfer protein; Plant Proteins; Protein Structure, Secondary; Protein Unfolding; Pru p 3; Prunus; Prunus - immunology; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; T cell receptors; T-Lymphocytes - immunology
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2011.04.020

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. Conclusion 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.