Major allergens of date palm (Phoenix dactylifera L.) pollen

Abstract

The IgE-binding components of date palm (Phoenix dactylifera L.) pollen were determined by ELISA and Western blotting in atopic patients in order to identify its major allergens. From a pool of previously identified allergenic fractions and sera from 15 skin-test-positive, atopic subjects, four components of 12, 14.4, 57, and 65-67 kDa were found to bind IgE in 80-93% of sera. Two other components of molecular masses 28-30 and 37-40 kDa also bound 60-80% of atopic sera. The immunologic specificity of date-pollen allergen that induced antibody response in sera of atopic patients was confirmed with ELISA. Furthermore, most of the reactivity in pooled positive atopic serum and antiserum raised in rabbits was eliminated after the sera were absorbed with the allergen. IgG immunoblot analyses showed varying degrees of cross-reactivity with common local allergens, notably Bermuda grass, but were generally of low intensity. These results indicate that date pollen has six major allergens with the 12, 14.4, 57, and 65-67 kDa bands binding 80-93%, and the 28-30 and 37-40 kDa bands 60-80% of atopic sera. We propose that these major allergens be assigned the notations "Pho d I" to "Pho d VI" in the order listed.

Cultivar-Specific IgE-Epitopes in Date (<i>Phoenix dactylifera</i> L.) Fruit Allergy

“…However, in that study only about 50% of patients’ sera bound IgE at 54–58 kDa. Studies on allergenicity of date palm pollen [3, 10, 12]and the present study on date fruits have all indicated that there are distinct differences in allergenicity and antigenicity of cultivars.…”

“…Due to the dioecious nature of the date palm, and the long period of cultivation in areas where it is used as a food crop, the palm is heterozygous and has resulted in the establishment of hundreds of varieties or cultivars. The allergenicity of date pollen has been established [10]and the allergenic variability of pollen from different cultivars of the date palm has been elucidated [3]. Since then, differences in the allergenicity of cultivars of other plants such as olives [11]pecan, wild chenopods and some amaranths have been demonstrated [12, 13].…”

“…Enhanced chemiluminescence (ECL) (Amersham International plc, Bucks, UK) detection method was used according to manufacturer’s guidelines followed by autoradiography. This method has increased sensitivity and made it possible to detect some of the weaker reacting bands [10]. The resultant autoradiographs were photographed and kept as a permanent record.…”

Date Palm Pollen Allergoid: Characterization of Its Chemical-Physical and Immunological Properties

“…Sera derived from patients with skin prick test (SPT) were positive to highly allergenic cultivars as previously described [16]. …”

“…The existence of date palm cultivars which are differentially allergenic can create problems [12,13,14], making it difficult to devise precise in vitro and in vivo diagnosis, a factor which in turn creates gross underestimates of the real incidence of this kind of allergy [15]. The use of diagnostic extract prepared from highly allergenic cultivars which contain all major date pollen allergens is fundamental to identifying people affected by such a specific allergic disease and to develop a vaccine for specific immunotherapy [14, 16, 17]. …”