Comparative proteomics of common allergenic tree pollens of birch, alder
and hazel
Abstract
In addition to known allergens, other proteins in pollen can aid the
development of an immune response in allergic individuals. The
contribution of the “unknown” protein allergens is apparent in
phylogenetically related species where, despite of high homology of the
lead allergens, the degree of allergenic potential can vary greatly. The
aim of this study was to identify other potentially allergenic proteins
in pollen of three common and highly related allergenic tree species:
birch (Betula pendula), hazel (Corylus avellana) and alder (Alnus
glutinosa). For that purpose, we carried out a comprehensive,
comparative proteomic screening of the pollen from the three species. In
order to maximize protein recovery and coverage, different protein
extraction and isolation strategies during sample preparation were
employed. As a result, we report 2500 - 3000 identified proteins per
each of the pollen species. Identified proteins were further used for a
number of annotation steps, providing insight into differential
distribution of peptidases, peptidase inhibitors and other potential
allergenic proteins across the three species. Moreover, we carried out
functional enrichment analyses that, interestingly, corroborated high
species similarity in spite of their relatively distinct protein
profiles. We provide to our knowledge first insight into proteomes of
two very important allergenic pollen types, hazel and alder, where not
even transcriptomics data is available, and compared them to birch.
Datasets from this study can be readily used as protein databases, and
as such serve as basis for further functional studies.