CHARACTERIZATION OF ANTIGENS AND ALLERGENS OF DATE PALM (PHOENIX-DACTYLIFERA) POLLEN - IMMUNOLOGICAL ASSESSMENT OF ATOPIC PATIENTS USING WHOLE EXTRACT AND ITS FRACTIONS

Antigenic and allergenic components of date palm (Phoenix dactylifera) pollen were investigated to observe their effects on the skin test reactivity, lymphocyte blastogenesis and cytokine production in atopic and healthy individuals. Date pollen extracts were fractionated using SDS-PAGE and Sephacryl S-200 gel filtration. Western blotting of SDS-PAGE separated components with antiserum raised against whole pollen extract in rabbits revealed at least 22 immunoreactive bands ranging in molecular weight between 12 and 94 kD. The immunogenicity of the pollen extract was further confirmed by strong positive reactions in ELISA and Ouchterlony's double diffusion tests. Immunoblot analyses revealed IgG and IgE reactive components (14-94 kD for IgG and 12-90 kD for IgE) in the skin test-positive patients' sera against whole pollen extract. Fifteen of 60 atopics reacted positively to either whole or some fractions of date pollen extract when skin tested. In response to whole or components of date pollen extract atopic patients showed differential peripheral blood lymphocyte (PBL) proliferative response and cytokine (IL-2, IL-4) production when compared with PBL of normal subjects. Our findings strongly suggest that date palm pollen should be considered a reaginic component and should be included in the battery of allergens for determining the allergic status of atopic patients, particularly in those parts of the world where the date palm is grown commercially.