BELL PEPPERS (CAPSICUM-ANNUUM) EXPRESS ALLERGENS (PROFILIN, PATHOGENESIS-RELATED PROTEIN P23 AND BET V-1) DEPENDING ON THE HORTICULTURAL STRAIN

Background: Little is known about the role of bell peppers in food all ergy We collected sera from 11 patients with food allergy to bell pepp ers to analyze bell pepper extracts for allergen composition. Methods: Proteins of mature fruits of eight horticultural strains of bell pepp ers were extracted and tested with patients' sera for IgE binding and with monoclonal and polyclonal antibodies in immunoblot. Results: Prof ilin was detected in bell pepper extracts by an anti-celery profilin a ntibody. It showed high IgE binding activity in all extracts, which co uld be inhibited by recombinant birch pollen profilin. Anti-birch poll en monoclonal antibody BIP3, directed against birch pollen proteins be tween 30 and 69 kD, bound to bell pepper antigens of comparable molecu lar weights. A homologue of the major birch pollen allergen Bet v 1 wa s detected in four of eight horticultural strains of bell peppers, and was shown to bind IgE in 1 of the 11 patients. A 23-kD allergen of be ll peppers was shown to correspond to the 23-kD major paprika allergen by IgE absorption experiments. Its N-terminal sequence showed 100% id entity to P23 from tomatoes. Conclusion: The appearance of profilin in all and Bet v 1 in 50% of the tested horticultural strains indicates that bell peppers have to be considered potentially dangerous for Bet v I-and profilin-sensitized patients. Moreover, in 4 of 8 horticultura l strains of bell peppers a homologue of the osmotin-like protein P23 from tomatoes is responsible for substantial IgE binding. Contact with Bet v 1 and P23 homologues in bell peppers can therefore be minimized by avoidance of the respective horticultural strains.