Heterogeneity of a major allergen from olive (Olea europea) pollen

Studies were carried out in order to confirm and extend knowledge of the physico-chemical properties of an allergenic material found in the pollen of the olive tree (Olea europea). The sera from 88% of patients who were sensitive to olive pollen contained IgE that reacted with a 19,000 Mr component and many also reacted to a 17,000 Mr band as shown by SDS-PAGE immunoblotting. A monoclonal antibody (OL-1) produced to the 19,000 Mr component also reacted with the 17,000 Mr band, and with bands at 21,000 and 41,000 under non-reduced conditions. HPLC separation followed by SDS-PAGE and immunoblotting of the fractions indicated that the allergen fraction from which the 19,000 and 17,000 components were derived had a mol. wt between 50 and 60 kD. Isoelectricfocusing followed by immunoblotting and development with (OL-1) indicated heterogeneity of the allergen with respect to pI values. Two of the strongest components of the six identified which reacted with (OL-1) had pIs of about 5.0 and 6.0 confirming the published data. The study therefore showed that olive pollen contains a number of allergenic components, with various mol. wts and pI values, with some epitopes in common, which may in the native state be bound together or aggregated.