title: IgE epitopes of intact and digested Ara h 1: a comparative study in humans and rats.
abstract: BACKGROUND
  Allergen epitope characterization provides valuable information useful for the understanding of proteins as food allergens. It is believed that IgE epitopes in general are conformational, nevertheless, for food allergens known to sensitize through the gastrointestinal tract linear epitopes have been suggested to be of great importance.
  
  
  OBJECTIVE
  The aim of this study was to identify IgE specific epitopes of intact and digested Ara h 1, and to compare epitope patterns between humans and rats.
  
  
  METHODS
  Sera from five peanut allergic patients and five Brown Norway rats were used to identify intact and digested Ara h 1-specific IgE epitopes by competitive immunoscreening of a phage-displayed random hepta-mer peptide library using polyclonal IgE from the individual sera. The resulting peptide sequences were mapped on the surface of a three-dimensional structure of the Ara h 1 molecule to mimic epitopes using a computer-based algorithm.
  
  
  RESULTS
  Patients as well as rats were shown to have individual IgE epitope patterns. All epitope mimics were conformational and found to cluster into three different areas of the Ara h 1 molecule. Five epitope motifs were identified by patient IgE, which by far accounted for most of the eluted peptide sequences. Epitope patterns were rather similar for both intact and digested Ara h 1 as well as for humans and rats.
  
  
  CONCLUSIONS
  Individual patient specific epitope patterns have been identified for the major allergen Ara h 1. IgE binding epitopes have been suggested as biomarkers for persistency and severity of food allergy, wherefore recognition of particular epitope patterns or motifs could be a valuable tool for prevention, diagnosis, and treatment of food allergy.
authors.affiliation: National Food Institute, Division of Toxicology and Risk Assessment, Technical University of Denmark, Mørkhøj Bygade 19, Søborg, Denmark. kalb@food.dtu.dk
authors.forename: K L
authors.initials: KL
authors.lastname: Bøgh
authors.forename: H
authors.initials: H
authors.lastname: Nielsen
authors.forename: C B
authors.initials: CB
authors.lastname: Madsen
authors.forename: E N C
authors.initials: EN
authors.lastname: Mills
authors.forename: N
authors.initials: N
authors.lastname: Rigby
authors.forename: T
authors.initials: T
authors.lastname: Eiwegger
authors.forename: Z
authors.initials: Z
authors.lastname: Szépfalusi
authors.forename: E L
authors.initials: EL
authors.lastname: Roggen
mesh_terms: D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D052179:Antigens, Plant / Q000737:chemistry* / Q000276:immunology*; D010367:Arachis / Q000276:immunology; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology*; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology; D006023:Glycoproteins / Q000737:chemistry* / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D008297:Male; D008565:Membrane Proteins; D021183:Peanut Hypersensitivity / Q000276:immunology; D019151:Peptide Library; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology*; D051381:Rats; D055815:Young Adult
chemical_list: D000596:Amino Acids; D052179:Antigens, Plant; C500889:Ara h 1 protein, Arachis hypogaea; D000939:Epitopes; D006023:Glycoproteins; D008565:Membrane Proteins; D019151:Peptide Library; D010940:Plant Proteins; D007073:Immunoglobulin E