ALLERGENS FROM BIRCH POLLEN AND POLLEN OF THE EUROPEAN CHESTNUT SHARECOMMON EPITOPES

Type I allergy to pollen of the European chestnut (Castanea sativa) re presents a major cause of pollinosis in (sub) Mediterranean areas. Usi ng sera from 14 patients with established allergy to pollen of the Eur opean chestnut, 13/14 sera (92%) showed IgE-binding to a 22 kD protein , 2/14 (14%) displayed additional binding to a 14 kD protein and 1/14 (7%) bound only to the 14 kD protein of European chestnut pollen extra ct. Two monoclonal mouse antibodies, BIP 1 and BIP 4, directed against different epitopes of Bet v I (the major birch pollen allergen), and a rabbit antibody to recombinant birch profilin (rBet v II) were used to characterize the proteins of the European chestnut pollen. The reco mbinant birch pollen allergens, rBet v I and rBet v II (profilin) were employed to show common allergenic structures on proteins from both b irch and European chestnut pollen by IgE-inhibition experiments. Despi te the fact that the 22 kD protein displayed a higher molecular weight in comparison to the 17 kD major birch pollen allergen, Bet v I, we c ould demonstrate reactivity of both monoclonal antibodies, BIP 1 and B IP 4, with this protein. A complete inhibiton of IgE-binding to this 2 2 kD protein was shown by pre-incubating sera with purified recombinan t Bet v I. In addition, the 14 kD protein could be identified by IgE-i nhibition studies with recombinant Bet v II and by using a rabbit anti -profilin antibody as the profilin from pollen of the European chestnu t.