Olive pollen is the second most frequent cause of respiratory allergy in Spain, reaching first cause in areas where its cultivation is extensive, such as Andalusia. A Spanish research team has identified and characterized the set of proteins of this pollen, including its allergens, providing relevant information for the diagnosis of allergy.
The identification of two hundred allergenic proteins of the almost two thousand proteins that make up the proteome of olive pollen can help improve the diagnosis of this common allergy and throw new clues about the basic biology of this tree, according to research led by the Complutense University of Madrid (UCM).
The cultivated olive tree (Olea europaea variante europaea) is essential for the consumption of olive oil and olives in the Mediterranean region. In addition, the promotion of the Mediterranean diet has made olive cultivation spread to many other countries, such as the United States, China or Australia.
“In fact, it was the enormous interest in understanding the biological mechanisms of olive oil production that led to the identification of the set of genes, or genome, of the olive tree, the wild variant from which cultivated olive trees originate. The recent publication of these data and their easy access gave us an excellent opportunity to elucidate the proteome of olive pollen,” explains Pablo San Segundo, a pre-doctoral researcher at the Department of Biochemistry and Molecular Biology of the UCM and co-principal author of the work, which has been published in the Journal of Proteome Research.
To carry out the study, the researchers had access to a high-performance technology known as mass spectrometry coupled to liquid chromatography through the Proteomics and Genomics Unit of the Center for Biological Research of the CSIC. With this technique, the scientists managed to identify almost two thousand different proteins, most of them involved in metabolic processes that occur during pollination.
“It is a complex and highly sensitive technique in which proteins are first cleaved into smaller parts called peptides, and then identify their amino acid sequence compared to a database, which in this case was the genome of the olive tree,” says Rodrigo Barderas, senior scientist at the Carlos III Health Institute.
Patient serum tests
Mayte Villalba, Professor of Biochemistry and Molecular Biology at the UCM, explains that when high levels of pollen are released into the environment and come into contact with the immune system of people predisposed to allergy, it stops recognizing certain proteins of pollen as harmless, then developing in front of some of them an allergic reaction with its consequent symptoms.
“Those proteins that cause allergy are known as allergens, and belong to very specific protein groups, usually with essential functions for the plant,” adds the UCM researcher. Comparing the proteins identified with the allergen databases, the researchers found 200 proteins distributed in 43 groups of allergens, 20 of which had not previously been described in olive pollen.
To conclude the study, the scientists used serum from patients allergic to olive pollen to confirm the clinical importance of any of the new potential allergens detected. Thus, they found that 15% of the analyzed patients, mostly children with severe respiratory symptoms, were sensitized to a protein that belongs to the group of cyclophilin allergens and has been named as Ole e 15, following the nomenclature allergen officer.
The study, which has the participation of two hospitals that collaborate in the thematic network of cooperative research in health Aradyal, Reina Sofía de Córdoba and the Jiménez Díaz Foundation, concludes that having identified the complete catalog of allergens of olive pollen will allow specifically determine to which allergens patients are sensitized and thus improve their diagnosis and treatment.
Source: SINC
