Apples Can Drive BIrch-PoIIen-AIIergic Patients Nuts! T-Cell Crossreactlvlty as a Basis for Food Allergy

摘要

Background: Birch-pollen-allergic patients frequently develop allergic reactions to certain foods, e.g., apples, hazelnuts and celery, because these foods contain proteins highly homologous to the major birch pollen allergen, Bet v 1. Bet v 1-specific IgE antibodies crossrreact with these homo-logs resulting in IgE-mediated immediate symptoms, such as the oral allergy syndrome, after the consumption of fresh foods. Methods: The T-cell response to the Bet v 1-related food allergens Maid 1 (apple), Cor a 1 (hazelnut) and Api g 1 (celery) was characterized using allergen-specific T-cell lines and clones. Moreover, T-cell crossreactivity of food allergens with Bet v 1-specific T-cell cultures was analyzed. Results: The T-cell response to Bet v 1-related food allergens was found to be Th2-domi-nated. Mal d 1, Api g 1 and Cor a 1 contained several T-cell epitopes matching relevant T-cell-acti-vating regions of Bet v 1. Accordingly, they induced proliferation and eytokine production of Bet v 1-specific T-cells. These T-cell-stimulatory properties of food allergens resisted simulated gastrointestinal digestion and heat processing because both treatments did not destroy relevant T-cell epitopes. Moreover, T-cell crossreactivity caused late phase reactions in the skin of birch-pollen-allergic patients with atopic dermatitis. Conclusions: Our data emphasize that birch-pollen-related foods represent potent stimuli of pollen-specific T-cells which can be relevant for late phase reactions in birch-pollen-allergic patients with atopic dermatitis.