title: A novel approach for investigation of specific and cross-reactive IgE epitopes on Bet v 1 and homologous food allergens in individual patients.
abstract: BACKGROUND
  A clinically relevant allergic reaction requires recognition of at least two different epitopes on the surface of the allergen by IgE. These epitopes may be specific or cross-reactive. Moreover, patterns of IgE reactivity may be patient-specific. The aim of our study was to compare specific and cross-reactive IgE epitopes and epitope patterns between individual patients. We used Bet v 1-related food allergy as a model.
  
  
  METHODS
  Five patients were investigated by cross-competitive ELISA for specific and cross-reacting IgE to Bet v 1, and its homologues Gly m 4 (soybean), Ara h 8 (peanut), and Pru av 1 (cherry). Allergen-specific as well as cross-reactive IgE epitopes were assessed by competitive immunoscreening of a phage-displayed random 7-mer peptide library using polyclonal purified IgE from individual sera. The resulting peptide mimics were mapped on the surface of the 3D-structure of the allergens using a computer-based algorithm.
  
  
  RESULTS
  Competitive immunoscreening and epitope mapping identified patient-specific IgE epitope patterns. However, one IgE-binding surface area that was recognized by all patients and two recognized by three patients were identified on all four proteins. These results are consistent with the determination of IgE cross-reactivity of the individual patients' sera against the four recombinant allergens by cross-competitive ELISA.
  
  
  CONCLUSIONS
  Selection of phage-displayed peptide mimics with serum IgE from allergic patients in combination with computer-based mapping of the peptide mimics onto the surface of the three-dimensional allergen structure is a promising novel tool to investigate IgE epitope specificity in individual patients. Such basic information on epitope structure may be used for prediction of cross-reactivity and potential allergenicity of novel foods.
authors.affiliation: Allergy Unit, Department of Dermatology, University Hospital Zurich, Switzerland.
authors.forename: Diana
authors.initials: D
authors.lastname: Mittag
authors.forename: Vincent
authors.initials: V
authors.lastname: Batori
authors.forename: Philipp
authors.initials: P
authors.lastname: Neudecker
authors.forename: Regina
authors.initials: R
authors.lastname: Wiche
authors.forename: Esben P
authors.initials: EP
authors.lastname: Friis
authors.forename: Barbara K
authors.initials: BK
authors.lastname: Ballmer-Weber
authors.forename: Stefan
authors.initials: S
authors.lastname: Vieths
authors.forename: Erwin L
authors.initials: EL
authors.lastname: Roggen
mesh_terms: D055516:2S Albumins, Plant; D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000097:blood / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology; D052179:Antigens, Plant; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology*; D005260:Female; D005512:Food Hypersensitivity / Q000097:blood / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000032:analysis / Q000097:blood / Q000276:immunology*; D008297:Male; D019151:Peptide Library; D010940:Plant Proteins / Q000097:blood / Q000276:immunology*; D030262:Soybean Proteins / Q000276:immunology; D040681:Structural Homology, Protein
chemical_list: D055516:2S Albumins, Plant; D000485:Allergens; D052179:Antigens, Plant; C492737:Ara h 6 allergen, Arachis hypogaea; C405762:Bet v 7 protein, Betula verrucosa; D000939:Epitopes; D019151:Peptide Library; D010940:Plant Proteins; C479400:Pru av 1 allergen, Prunus avium; D030262:Soybean Proteins; D007073:Immunoglobulin E