Abstract
Background: The allergens responsible for cashew food allergy have not been well characterized. Objectives: We initiated a study to clone cDNAs encoding cashew food allergens. Methods: A cashew cDNA library was screened with human serum for IgE-reactive clones and rabbit IgG anti-cashew extract antisera. Reactive clones were sequenced and expressed, and linear epitopes were identified by means of solid-phase overlapping peptide analysis. Immunoblot inhibition was used to identify the native peptide in cashew extract. Results: Four closely related clones reactive with both human and rabbit antisera were sequenced. Sequence analysis showed that these encode members of the vicilin/sucrose-binding protein family of plant seed storage proteins. Screening of the recombinant protein with sera from 20 patients with cashew allergy and 8 cashew-tolerant patients with allergies to other tree nuts showed that 50% and 25% of sera from patients with cashew allergy and cashew-tolerant subjects, respectively, bound the recombinant protein. The corresponding native allergen protein, designated Ana o 1, was located at approximately 50 kd. Epitope mapping revealed 11 linear IgE-binding epitopes, of which 3 appear to be immunodominant. None of the epitopes were shared in common with those of the peanut vicilin allergen Ara h 1. Conclusion: Ana o 1, a vicilin-like protein, is a major food allergen in cashews. Cashew and peanut vicilins do not share linear epitopes.
Original language | English (US) |
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Pages (from-to) | 160-166 |
Number of pages | 7 |
Journal | Journal of Allergy and Clinical Immunology |
Volume | 110 |
Issue number | 1 |
DOIs | |
State | Published - 2002 |
Keywords
- 7S globulin
- Ana o 1
- Anacardium occidental
- Cashew allergy
- Epitope map
- Food allergy
- Linear epitope
- Seed storage proteins
- Sucrose-binding protein
- Tree nut allergy
- Vicilin
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology