Art v 1 IgE epitopes of patients and humanized mice are conformationalZabel, Maja (Avtor) Weber, Milena (Avtor) Kratzer, Bernhard (Avtor) Köhler, Cordula (Avtor) Jahn-Schmid, Beatrice (Avtor) Gadermaier, Gabriele (Avtor) Gattinger, Pia (Avtor) Bidovec, Urška (Avtor) Korošec, Peter (Avtor) Smole, Ursula (Avtor) Valenta, Rudolf (Avtor) Pickl, Winfried F. (Avtor) mugwort pollen allergyIgE epitopeallergen-specific immunotherapyBackground: Worldwide, pollen of the weed mugwort (Artemisia vulgaris) is a major cause of severe respiratory allergy, with its major allergen, Art v 1, being the key pathogenic molecule for millions of patients. Humanized mice transgenic for a human T-cell receptor specific for the major Art v 1 T-cell epitope and the corresponding HLA have been made. Objective: We sought to characterize IgE epitopes of Art v 1–sensitized patients and humanized mice for molecular immunotherapy of mugwort allergy. Methods: Four overlapping peptides incorporating surface-exposed amino acids representing the full-length Art v 1 sequence were synthesized and used to search for IgE reactivity to sequential epitopes. For indirect mapping, peptide-specific rabbit antibodies were raised to block IgE against surface-exposed epitopes on folded Art v 1. IgE reactivity and basophil activation studies were performed in clinically defined mugwort-allergic patients. Secondary structure of recombinant (r) Art v 1 and peptides was determined by circular dichroism spectroscopy. Results: Mugwort-allergic patients and humanized mice sensitized by allergen inhalation showed IgE reactivity and/or basophil activation mainly to folded, complete Art v 1 but not to unfolded, sequential peptide epitopes. Blocking of allergic patients’ IgE with peptide-specific rabbit antisera identified a hitherto unknown major conformational IgE binding site in the C-terminal Art v 1 domain. Conclusions: Identification of the new major conformational IgE binding site on Art v 1, which can be blocked with IgG raised against non-IgE reactive Art v 1 peptides, is an important basis for the development of a hypoallergenic peptide vaccine for mugwort allergy.20222022-08-31 14:21:20Neznano15408sl