Tropomyosin in mugwort cross-reacts to house dust mite, eliciting non-Th2 response in allergic rhinitis patients sensitized to house dust mite

Abstract

Background Mugwort and house dust mite (HDM) are two of the most common inhalant allergens in Asia, however, whether mugwort affects polysensitized HDM+ allergic rhinitis (AR) patients has not been elucidated. Methods Overall, 15,884 AR outpatients were assessed for clinical status. Amino acid sequences of mugwort were determined by mass spectrometry. Afterward, cross-reactivity between mugwort tropomyosin and Dermatophagoides pteronyssinus 10 (Der p10) was analysed by ELISA inhibition and basophil activation experiments. To compare immunologic responses eliciting by two different tropomyosins, peripheral blood mononuclear cells (PBMCs) of HDM-monosensitized patients were stimulated by mugwort, HDM, Der p10 and synthetic peptides representing mugwort tropomyosin respectively. Results Polysensitized HDM+AR patients were mainly sensitized to cat and mugwort, and the positive rate of monosensitized HDM+AR out-clinic patients was increased during the mugwort pollen season. Tropomyosin protein was able to find in mugwort. Synthetic tropomyosin peptide of mugwort activated basophils which were primed by HDM-specific IgE; ELISA inhibition experiment showed synthetic tropomyosin peptide of mugwort inhibited IgE binding to HDM tropomyosin, Der p10. Unlike HDM and Derp 10, mugwort and mugwort tropomyosin mainly induced IFN-γ and IL-17 release in PBMCs of monosensitized HDM+AR patients, but not IL-5. Conclusions Pan-allergen tropomyosin accounts for the cross-reactivity between mugwort and HDM, which reminds HDM+ patients to reduce mugwort exposure in mugwort pollen season in virtue of the tropomyosin induced mild inflammation.

An overview of tropomyosin as an important seafood allergen: Structure, cross‐reactivity, epitopes, allergenicity, and processing modifications

“…The structure and sequence similarity of TM is the foundation of cross‐reactivity among different arthropod species. The high homology in the sequence is up to 98% among crustacean TMs, and 68%−100% among molluskan TMs (Duan et al., 2021; Palmer et al., 2020; Prester, 2016). Similarly, the high homology in the sequence is 80%−97% among crustaceans and house dust mite TMs and 78%−98% among crustacean and cockroach TMs.…”

Comparative analysis of chronic rhinitis patient profiles during autumn pollen season between grassland and non-grassland cities in North China

“…A longitudinal study from 18 major cities in China showed that the self-reported prevalence of AR in adults increased by 6.5% in 6 years [ 4 ]. Mugwort and house dust mites are the two most commonly inhaled allergens in Asia [ 5 ]. In North China, more than 50% of individuals with respiratory allergy are allergic to Artemisia pollen [ 6 ].…”