title: Tackling Bet v 1 and associated food allergies with a single hybrid protein.
abstract: BACKGROUND
  Allergy vaccines should be easily applicable, safe, and efficacious. For Bet v 1-mediated birch pollen and associated food allergies, a single wild-type allergen does not provide a complete solution.
  
  
  OBJECTIVE
  We aimed to combine immunologically relevant epitopes of Bet v 1 and the 2 clinically most important related food allergens from apple and hazelnut to a single hybrid protein, termed MBC4.
  
  
  METHODS
  After identification of T cell epitope-containing parts on each of the 3 parental allergens, the hybrid molecule was designed to cover relevant epitopes and evaluated in silico. Thereby a mutation was introduced into the hybrid sequence, which should alter the secondary structure without compromising the immunogenic properties of the molecule.
  
  
  RESULTS
  MBC4 and the parental allergens were purified to homogeneity. Analyses of secondary structure elements revealed substantial changes rendering the hybrid de facto nonreactive with patients' serum IgE. Nevertheless, the protein was monomeric in solution. MBC4 was able to activate T-cell lines from donors with birch pollen allergy and from mice immunized with the parental allergens. Moreover, on immunization of mice and rabbits, MBC4 induced cross-reactive IgG antibodies, which were able to block the binding of human serum IgE.
  
  
  CONCLUSIONS
  Directed epitope rearrangements combined with a knowledge-based structural modification resulted in a protein unable to bind IgE from allergic patients. Still, properties to activate specific T cells or induce blocking antibodies were conserved. This suggests that MBC4 is a suitable vaccine candidate for the simultaneous treatment of Bet v 1 and associated food allergies.
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Heidi
authors.initials: H
authors.lastname: Hofer
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Claudia
authors.initials: C
authors.lastname: Asam
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Hauser
authors.affiliation: Department of Pathophysiology and Allergy Research and Christian Doppler Laboratory for Immunomodulation, Medical University of Vienna, Vienna, Austria.
authors.forename: Birgit
authors.initials: B
authors.lastname: Nagl
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Josef
authors.initials: J
authors.lastname: Laimer
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Himly
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Briza
authors.affiliation: Allergy Clinic Reumannplatz, Vienna, Austria.
authors.forename: Christof
authors.initials: C
authors.lastname: Ebner
authors.affiliation: Department of Dermatology, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Roland
authors.initials: R
authors.lastname: Lang
authors.affiliation: Department of Dermatology, Paracelsus Medical University, Salzburg, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hawranek
authors.affiliation: Department of Pathophysiology and Allergy Research and Christian Doppler Laboratory for Immunomodulation, Medical University of Vienna, Vienna, Austria.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bohle
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Peter
authors.initials: P
authors.lastname: Lackner
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria.
authors.forename: Fátima
authors.initials: F
authors.lastname: Ferreira
authors.affiliation: Department of Molecular Biology, University of Salzburg, Salzburg, Austria. Electronic address: michael.wallner@sbg.ac.at.
authors.forename: Michael
authors.initials: M
authors.lastname: Wallner
mesh_terms: D000485:Allergens / Q000235:genetics / Q000276:immunology*; D000818:Animals; D052179:Antigens, Plant / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D003429:Cross Reactions; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000097:blood / Q000276:immunology* / Q000628:therapy; D007114:Immunization; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008807:Mice, Inbred BALB C; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology*; D011817:Rabbits; D013601:T-Lymphocytes / Q000276:immunology; D014612:Vaccines
chemical_list: D000485:Allergens; D052179:Antigens, Plant; C061277:Cor a I protein, hazel; D018984:Epitopes, T-Lymphocyte; D007074:Immunoglobulin G; C095551:MALD1 protein, Malus domestica; D010940:Plant Proteins; D014612:Vaccines; C061312:Bet v 1 allergen, Betula; D007073:Immunoglobulin E
keywords: Bet v 1; Birch pollen allergy; allergy vaccine candidate; birch pollen–associated food allergy; molecular allergology