Bet v 1(142-156) is the dominant T-cell epitope of the major birch pollen allergen and important for cross-reactivity with Bet v 1-related food allergens

Paul-Ehrlich-Institut, Langen, Hesse, Germany
Journal of Allergy and Clinical Immunology (Impact Factor: 11.25). 08/2005; 116(1):213-9. DOI: 10.1016/j.jaci.2005.04.019
Source: PubMed

ABSTRACT Individuals with birch pollen allergy frequently experience hypersensitivity reactions to certain foods, primarily because of IgE antibodies specific for the major birch pollen allergen Bet v 1 that cross-react with homologous food allergens.
We sought to characterize the major T-cell epitopes of Bet v 1 and to investigate their involvement in the cellular cross-reactivity with homologous food allergens.
T-cell epitope mapping of Bet v 1 was performed by testing Bet v 1-specific T-cell lines derived from 57 individuals with birch pollen allergy, with overlapping peptides representing the entire allergen. T-cell lines and T-cell clones were stimulated with Bet v 1-related major allergens from apple (Mal d 1), cherry (Pru av 1), hazelnut (Cor a 1), celery (Api g 1), carrot (Dau c 1), and soybean (Gly m 4) and with peptides deduced from the C-terminal amino acid sequences of these molecules. Results Bet v 1 142-156 , positioned in the highly conserved C-terminal region of Bet v 1, was identified as the major T-cell epitope recognized by 61% of individuals. Most T lymphocytes specific for Bet v 1 142-156 were activated by one or more homologous food proteins or the respective peptides, as indicated by proliferation and cytokine production.
The major T-cell epitope of Bet v 1, Bet v 1 142-156 , plays an important role in the cellular cross-reactivity between this respiratory allergen and related food allergens. Thus T lymphocytes specific for Bet v 1 142-156 might be activated by various Bet v 1-related food allergens in vivo, even out of the pollen season.

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    • "PR10 proteins show a high degree of amino acid sequence identity with the birch pollen allergens of the Bet v 1 family and are the most important elicitors of pollen-related food allergy. Approximately 90% of patients allergic to birch pollen have IgE antibodies against Bet v 1 (Jahn-Schmid et al. 2005). Carrot (Daucus carota) allergy is also a common phenomenon in patients with birch pollen allergy. "
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