Hypersensitivity to Ailanthus altissima (tree of heaven) pollen: identification of a major IgE-binding component

Abstract

Ailanthusaltissima or Ailanthusglandulosa (Simaroubaceae) is known as tree of heaven. It is a dioecious plant with staminate and pistillate flowers that grow on separate trees. In recent years, A.altissima has been frequently planted in numerous areas, especially in arid and semiarid lands of Iran and also used as an ornamental tree in several Iran cities including Kerman. The aim of this research was to identify IgE-binding proteins responsible for type I hypersensitivities of A. altissima pollen extract. In this study, pollen’s proteins were extracted and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Total protein content of pollen extracts was measured by Bradford assay. Allergenicity of pollen extract was evaluated by skin test and immunoblotting. Results showed that total protein concentration of A.altissima pollen was found to be 1.34 μg μl−1. In A. altissima pollen extract, different protein fractions were identified by SDS-PAGE mostly at 42, 53.7, 63, 87.7, 100 and 120 kDa. Skin tests showed a delayed hypersensitivity. Immunoblotting of A. altissima pollen extract with pooled subject’s sera detected a major IgE-binding component of 42 kDa. Moreover, these results will provide a platform for cloning cDNA encoding allergenic protein from A.altissima pollen.