The group of Winfried Pickl published a study revealing that Art v 1 IgE epitopes of patients and humanized mice are conformational.

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.

Zabel M, Weber M, Kratzer B, Köhler C, Jahn-Schmid B, Gadermaier G, Gattinger P, Bidovec-Stojkovič U, Korošec P, Smole U, Wurzinger G, Chen KW, Panaitescu CB, Klimek L, Pablos I, Niespodziana K, Neunkirchner A, Keller W, Valenta R, Pickl WF. (2022). Art v 1 IgE epitopes of patients and humanized mice are conformational. J Allergy Clin Immunol. 2022 Jun 20:S0091-6749(22)00701-1. doi: 10.1016/j.jaci.2022.04.031. Online ahead of print. PMID: 35738928