Similar Allergenicity to Different Species Is a Consequence of Highly Cross-Reactive Art v 1-Like Molecules.

Pollens of weeds are relevant elicitors of type I allergies. While many species occur worldwide, allergy research so far has only focused on . We aimed to characterize other prevalent species regarding their allergen profiles. Aqueous extracts of pollen from seven species were characterized by gel electrophoresis and ELISA using sera from mugwort pollen-allergic patients ( = 11). The cDNA sequences of defensin-proline-linked proteins (DPLPs) were obtained, and purified proteins were tested in a competition ELISA, in rat basophil mediator release assays, and for activation of Jurkat T cells transduced with an Art v 1-specific TCR. IgE cross-reactivity to other allergens was evaluated using ImmunoCAP and ISAC. The protein patterns of spp. pollen extracts were similar in gel electrophoresis, with a major band at 24 kDa corresponding to DPLPs, like the previously identified Art v 1. Natural Art v 1 potently inhibited IgE binding to immobilized pollen extracts. Six novel Art v 1 homologs with high sequence identity and equivalent IgE reactivity were identified and termed Art ab 1, Art an 1, Art c 1, Art f 1, Art l 1, and Art t 1. All proteins triggered mediator release and cross-reacted at the T cell level. The extracts contained additional IgE cross-reactive molecules from the nonspecific lipid transfer protein, pectate lyase, profilin, and polcalcin family. Our findings demonstrate that DPLPs in various species have high allergenic potential. Therefore, related species need to be considered to be allergen elicitors, especially due to the consideration of potential geographic expansion due to climatic changes.