ABSTRACT
Immunoglobulin E (IgE)-mediated allergy affects more than 25% of the world’s population and proteins from trees, grasses, and mites are the most important causes of this disease. In trees, allergenic proteins can either occur in pollen, fruits, or seeds. Trees, recognized as major pollen allergen sources, belong to certain botanical orders with defined geographical distributions and flowering periods. Tree pollen allergens characterized to date represent predominantly low-molecular-weight intracellular proteins or glycoproteins that are rapidly released after contact of pollen with aqueous solutions. Carbohydrate moieties may represent cross-reactive IgE epitopes occurring in tree pollen and several unrelated allergen sources but seem to have little clinical relevance. Pollen grains are single cells that contain within themselves the male reproductive cells, the sperm cells. The rapid progress of allergen characterization through the application of molecular cloning techniques has provided recombinant allergens covering most allergen sources, including trees.
