title: Characterization of causative allergens for wheat-dependent exercise-induced anaphylaxis sensitized with hydrolyzed wheat proteins in facial soap.
abstract: BACKGROUND
  In Japan, hydrolyzed wheat proteins (HWP) have been reported to cause wheat-dependent exercise-induced anaphylaxis (WDEIA) by transcutaneous sensitization using HWP-containing soap. Patients develop allergic reactions not only with soap use, but also with exercise after the intake of wheat protein (WP). ω5-Gliadin and HMW-glutenin were identified as major allergens in conventional WP-WDEIA patients. However, the allergens in HWP-WDEIA have yet to be elucidated.
  
  
  METHODS
  Sera were obtained from 22 patients with HWP-sensitized WDEIA. The allergenic activities of HWP and six recombinant wheat gluten proteins, including α/β-, γ-, ω1,2- and ω5-gliadin and low- and high molecular weight (HMW)-glutenins, were characterized by immunoblot analysis and histamine releasing test. IgE-binding epitopes were identified using arrays of overlapping peptides synthesized on SPOTs membrane.
  
  
  RESULTS
  Immunoblot analysis showed that IgE antibodies (Abs) from HWP-WDEIA bound to α/β-, γ- and ω1,2-gliadin. Recombinant γ-gliadin induced significant histamine release from basophils in eight of 11 patients with HWP-WDEIA. An IgE-binding epitope "QPQQPFPQ" was identified within the primary sequence of γ-gliadin, and the deamidated peptide containing the "PEEPFP" sequence bound with IgE Abs more strongly compared to the native epitope-peptide. The epitope-peptide inhibited IgE-binding to HWP, indicating that the specific IgE to HWP cross-reacts with γ-gliadin.
  
  
  CONCLUSIONS
  HWP-WDEIA patients could be sensitized to HWP containing a PEEPFP sequence, and WDEIA symptoms after WP ingestion could partly be induced by γ-gliadin. These findings could be useful to help develop tools for diagnosis and desensitization therapy for HWP-WDEIA.
authors: Department of Pathophysiology and Therapeutics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
authors: Tomoharu
authors: T
authors: Yokooji
authors: Saki
authors: S
authors: Kurihara
authors: Tomoko
authors: T
authors: Murakami
authors: Yuko
authors: Y
authors: Chinuki
authors: Hitoshi
authors: H
authors: Takahashi
authors: Eishin
authors: E
authors: Morita
authors: Susumu
authors: S
authors: Harada
authors: Kaori
authors: K
authors: Ishii
authors: Makiko
authors: M
authors: Hiragun
authors: Michihiro
authors: M
authors: Hide
authors: Hiroaki
authors: H
authors: Matsuo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000485:Allergens / Q000737:chemistry / Q000276:immunology; D000707:Anaphylaxis / Q000276:immunology*; D052179:Antigens, Plant / Q000276:immunology; D001491:Basophils / Q000276:immunology; D002478:Cells, Cultured; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000276:immunology / Q000302:isolation & purification; D015444:Exercise; D005260:Female; D005903:Gliadin / Q000737:chemistry / Q000276:immunology*; D005983:Glutens / Q000276:immunology; D006632:Histamine / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D007114:Immunization; D007073:Immunoglobulin E / Q000378:metabolism; D007564:Japan; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology; D012915:Soaps / Q000009:adverse effects* / Q000737:chemistry; D014908:Triticum / Q000737:chemistry / Q000276:immunology*; D021182:Wheat Hypersensitivity / Q000276:immunology*; D055815:Young Adult
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D018985:Epitopes, B-Lymphocyte; D010446:Peptide Fragments; D012915:Soaps; C475180:omega-5 gliadin, wheat; D007073:Immunoglobulin E; D005983:Glutens; D006632:Histamine; D005903:Gliadin; C037302:glutenin