Delineation of the Olive Pollen Proteome and Its Allergenome Unmasks Cyclophilin as a Relevant Cross-Reactive Allergen

Abstract

Olive pollen is a major allergenic source worldwide due to its extensive cultivation. We have combined available genomics data with a comprehensive proteomics approach to get the annotated olive tree (<i>Olea europaea</i> L.) pollen proteome and define its complex allergenome. A total of 1907 proteins were identified by LC-MS/MS using predicted protein sequences from its genome. Most proteins (60%) were predicted to possess catalytic activity and be involved in metabolic processes. In total, 203 proteins belonging to 47 allergen families were found in olive pollen. A peptidyl-prolyl <i>cis-trans</i> isomerase, cyclophilin, produced in <i>Escherichia coli</i>, was found as a new olive pollen allergen (Ole e 15). Most Ole e 15-sensitized patients were children (63%) and showed strong IgE recognition to the allergen. Ole e 15 shared high sequence identity with other plant, animal, and fungal cyclophilins and presented high IgE cross-reactivity with pollen, plant food, and animal extracts.