1. Art v 1 IgE epitopes of patients and humanized mice are conformationalMaja Zabel, Milena Weber, Bernhard Kratzer, Cordula Köhler, Beatrice Jahn-Schmid, Gabriele Gadermaier, Pia Gattinger, Urška Bidovec, Peter Korošec, Ursula Smole, Rudolf Valenta, Winfried F. Pickl, 2022, original scientific article Abstract: Background: 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. Keywords: mugwort pollen allergy, IgE epitope, allergen-specific immunotherapy Published in DiRROS: 31.08.2022; Views: 994; Downloads: 401 Link to file |
2. Safety and efficacy of immunotherapy with the recombinant B-cell epitope-based grass pollen vaccine BM32Verena Niederberger, Angela Neubauer, Philippe Gevaert, Mihaela Zidarn, Margitta Worm, Werner Aberer, Hans Jørgen Malling, Oliver Pfaar, Ludger Klimek, Wolfgang Pfützner, 2018, original scientific article Abstract: Background BM32 is a grass pollen allergy vaccine based on recombinant fusion proteins consisting of nonallergenic peptides from the IgE-binding sites of the 4 major grass pollen allergens and the hepatitis B preS protein. Objective We sought to study the safety and clinical efficacy of immunotherapy (allergen immunotherapy) with BM32 in patients with grass pollen-induced rhinitis and controlled asthma. Methods A double-blind, placebo-controlled, multicenter allergen immunotherapy field study was conducted for 2 grass pollen seasons. After a baseline season, subjects (n = 181) were randomized and received 3 preseasonal injections of either placebo (n = 58) or a low dose (80 [micro]g, n = 60) or high dose (160 [micro]g, n = 63) of BM32 in year 1, respectively, followed by a booster injection in autumn. In the second year, all actively treated subjects received 3 preseasonal injections of the BM32 low dose, and placebo-treated subjects continued with placebo. Clinical efficacy was assessed by using combined symptom medication scores, visual analog scales, Rhinoconjunctivitis Quality of Life Questionnaires, and asthma symptom scores. Adverse events were graded according to the European Academy of Allergy and Clinical Immunology. Allergen-specific antibodies were determined by using ELISA, ImmunoCAP, and ImmunoCAP ISAC. Results Although statistical significance regarding the primary end point was not reached, BM32-treated subjects, when compared with placebo-treated subjects, showed an improvement regarding symptom medication, visual analog scale, Rhinoconjunctivitis Quality of Life Questionnaire, and asthma symptom scores in both treatment years. This was accompanied by an induction of allergen-specific IgG without induction of allergen-specific IgE and a reduction in the seasonally induced increase in allergen-specific IgE levels in year 2. In the first year, more grade 2 reactions were observed in the active (n = 6) versus placebo (n = 1) groups, whereas there was almost no difference in the second year. Conclusions Injections of BM32 induced allergen-specific IgG, improved clinical symptoms of seasonal grass pollen allergy, and were well tolerated. Keywords: allergy, allergen immunotherapy, B-cell epitope-based immunotherapy Published in DiRROS: 17.12.2020; Views: 1737; Downloads: 1045 Full text (3,82 MB) This document has many files! More... |