Characterization of Causative Allergens for Wheat-Dependent Exercise-Induced Anaphylaxis Sensitized with Hydrolyzed Wheat Proteins in Facial Soap (1)
ω5-Gliadin and HMW-glutenin were identified as major allergens in conventional WP-WDEIA patients, whereas the aller- gens and their IgE Ab binding epitopes in HWP- WDEIA patients have not been identified.
Gene bank#: AF120267 (γ-gliadin), and AB 181300 (ω5-gliadin),
The PCR product of ω5-gliadin digested with NdeI and SalI was ligated to pCold III vector.
HWP appeared as smeared band on SDS-PAGE with CBB staining while separated bands were detected in WPs.
Sera from all HWP-WDEIA patients showed the smear IgE-binding to HWP in wide molecular weight ranges by western blotting.
Most patients with WP-WDEIA showed specific IgE-binding to ω5-gliadin and HMW-glutenin, confirming previous reports. In contrast to WP-WDEIA patients, higher specific IgE-reactivity to α!β-,γ-, and ω1,2-gliadin were observed in HWP-WDEIA patients.
The histamine re- leases were observed by γ-gliadin in 8 of 11 HWP- WDEIA patients, and with α/β- and ω1,2-gliadins in one of 11 patients each. No histamine release was induced by ω5-gliadin.
Sera from three patients re- acted with many peptides, in particular, the sequence “QFLQPQQPFPQQPQ” of peptide 9 was recognized most strongly by IgE Abs of 2 HWP-WDEIA patients
The common IgE-binding epitope in HWP- WDEIA was QPQQPFPQ. The substitutions generally increased IgE binding to peptides, and the common epitope was determined as PEEPFP.
Specific IgEs to HWP cross-react with the QFLQPQQPFPQQPQ aa sequence from γ-gliadin, and the IgE-binding ability could be enhanced by deamidation.
