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Öztemiz Topcu E, Gadermaier G. To stay or not to stay intact as an allergen: the endolysosomal degradation assay used as tool to analyze protein immunogenicity and T cell epitopes. FRONTIERS IN ALLERGY 2024; 5:1440360. [PMID: 39071040 PMCID: PMC11272489 DOI: 10.3389/falgy.2024.1440360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Accepted: 06/25/2024] [Indexed: 07/30/2024] Open
Abstract
Antigen uptake and processing of exogenous proteins is critical for adaptive immunity, particularly for T helper cell activation. Proteins undergo distinct proteolytic processing in endolysosomal compartments of antigen-presenting cells. The resulting peptides are presented on MHC class II molecules and specifically recognized by T cells. The in vitro endolysosomal degradation assay mimics antigen processing by incubating a protein of interest with a protease cocktail derived from the endolysosomal compartments of antigen presenting cells. The kinetics of protein degradation is monitored by gel electrophoresis and allows calculation of a protein's half-life and thus endolysosomal stability. Processed peptides are analyzed by mass spectrometry and abundant peptide clusters are shown to harbor T cell epitopes. The endolysosomal degradation assay has been widely used to study allergens, which are IgE-binding proteins involved in type I hypersensitivity. In this review article, we provide the first comprehensive overview of the endolysosomal degradation of 29 isoallergens and variants originating from the PR-10, Ole e 1-like, pectate lyase, defensin polyproline-linked, non-specific lipid transfer, mite group 1, 2, and 5, and tropomyosin protein families. The assay method is described in detail and suggestions for improved standardization and reproducibility are provided. The current hypothesis implies that proteins with high endolysosomal stability can induce an efficient immune response, whereas highly unstable proteins are degraded early during antigen processing and therefore not efficient for MHC II peptide presentation. To validate this concept, systematic analyses of high and low allergenic representatives of protein families should be investigated. In addition to purified molecules, allergen extracts should be degraded to analyze potential matrix effects and gastrointestinal proteolysis of food allergens. In conclusion, individual protein susceptibility and peptides obtained from the endolysosomal degradation assay are powerful tools for understanding protein immunogenicity and T cell reactivity. Systematic studies and linkage with in vivo sensitization data will allow the establishment of (machine-learning) tools to aid prediction of immunogenicity and allergenicity. The orthogonal method could in the future be used for risk assessment of novel foods and in the generation of protein-based immunotherapeutics.
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Peterkova L, Trifonova D, Gattinger P, Focke-Tejkl M, Garib V, Magbulova N, Djambekova G, Zakhidova N, Ismatova M, Sekerel BE, Tuten Dal S, Tulaev M, Kundi M, Keller W, Karaulov A, Valenta R. The cytoskeletal protein profilin is an important allergen in saltwort ( Salsola kali). Front Immunol 2024; 15:1379833. [PMID: 38911871 PMCID: PMC11190152 DOI: 10.3389/fimmu.2024.1379833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 05/13/2024] [Indexed: 06/25/2024] Open
Abstract
Pollen from Salsola kali, i.e., saltwort, Russian thistle, is a major allergen source in the coastal regions of southern Europe, in Turkey, Central Asia, and Iran. S. kali-allergic patients mainly suffer from hay-fever (i.e., rhinitis and conjunctivitis), asthma, and allergic skin symptoms. The aim of this study was to investigate the importance of individual S. kali allergen molecules. Sal k 1, Sal k 2, Sal k 3, Sal k 4, Sal k 5, and Sal k 6 were expressed in Escherichia coli as recombinant proteins containing a C-terminal hexahistidine tag and purified by nickel affinity chromatography. The purity of the recombinant allergens was analyzed by SDS-PAGE. Their molecular weight was determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and their fold and secondary structure were studied by circular dichroism (CD) spectroscopy. Sera from clinically well-characterized S. kali-allergic patients were used for IgE reactivity and basophil activation experiments. S. kali allergen-specific IgE levels and IgE levels specific for the highly IgE cross-reactive profilin and the calcium-binding allergen from timothy grass pollen, Phl p 12 and Phl p 7, respectively, were measured by ImmunoCAP. The allergenic activity of natural S. kali pollen allergens was studied in basophil activation experiments. Recombinant S. kali allergens were folded when studied by CD analysis. The sum of recombinant allergen-specific IgE levels and allergen-extract-specific IgE levels was highly correlated. Sal k 1 and profilin, reactive with IgE from 64% and 49% of patients, respectively, were the most important allergens, whereas the other S. kali allergens were less frequently recognized. Specific IgE levels were highest for profilin. Of note, 37% of patients who were negative for Sal k 1 showed IgE reactivity to Phl p 12, emphasizing the importance of the ubiquitous cytoskeletal actin-binding protein, profilin, for the diagnosis of IgE sensitization in S. kali-allergic patients. rPhl p 12 and rSal k 4 showed equivalent IgE reactivity, and the clinical importance of profilin was underlined by the fact that profilin-monosensitized patients suffered from symptoms of respiratory allergy to saltwort. Accordingly, profilin should be included in the panel of allergen molecules for diagnosis and in molecular allergy vaccines for the treatment and prevention of S. kali allergy.
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Affiliation(s)
- Ludmila Peterkova
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Daria Trifonova
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Pia Gattinger
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Margarete Focke-Tejkl
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- Karl Landsteiner University, Krems an der Donau, Austria
| | - Victoria Garib
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- Ministry of Higher Education, Science and Innovation, Tashkent, Uzbekistan
| | - Nigora Magbulova
- International Center of Molecular Allergology, Ministry of Higher Education, Science and Innovation, Tashkent, Uzbekistan
| | - Gulnara Djambekova
- International Center of Molecular Allergology, Ministry of Higher Education, Science and Innovation, Tashkent, Uzbekistan
| | | | | | - Bulent Enis Sekerel
- Pediatric Allergy and Asthma Division, Hacettepe University School of Medicine, Ankara, Türkiye
| | - Sevda Tuten Dal
- Pediatric Allergy and Asthma Division, Hacettepe University School of Medicine, Ankara, Türkiye
| | - Mikhail Tulaev
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Michael Kundi
- Karl Landsteiner University, Krems an der Donau, Austria
- Department of Environmental Health, Center for Public Health, Medical University of Vienna, Vienna, Austria
| | - Walter Keller
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, Graz, Austria
| | - Alexander Karaulov
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Rudolf Valenta
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia
- Karl Landsteiner University, Krems an der Donau, Austria
- National Research Center, National Research Center Institute of Immunology (NRCI) Institute of Immunology, Federal Medical-Biological Agency of Russia (FMBA), Moscow, Russia
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Wróblewska B, Kuliga A, Wnorowska K. Bioactive Dairy-Fermented Products and Phenolic Compounds: Together or Apart. Molecules 2023; 28:8081. [PMID: 38138571 PMCID: PMC10746084 DOI: 10.3390/molecules28248081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Fermented dairy products (e.g., yogurt, kefir, and buttermilk) are significant in the dairy industry. They are less immunoreactive than the raw materials from which they are derived. The attractiveness of these products is based on their bioactivity and properties that induce immune or anti-inflammatory processes. In the search for new solutions, plant raw materials with beneficial effects have been combined to multiply their effects or obtain new properties. Polyphenols (e.g., flavonoids, phenolic acids, lignans, and stilbenes) are present in fruit and vegetables, but also in coffee, tea, or wine. They reduce the risk of chronic diseases, such as cancer, diabetes, or inflammation. Hence, it is becoming valuable to combine dairy proteins with polyphenols, of which epigallocatechin-3-gallate (EGCG) and chlorogenic acid (CGA) show a particular predisposition to bind to milk proteins (e.g., α-lactalbumin β-lactoglobulin, αs1-casein, and κ-casein). Reducing the allergenicity of milk proteins by combining them with polyphenols is an essential issue. As potential 'metabolic prebiotics', they also contribute to stimulating the growth of beneficial bacteria and inhibiting pathogenic bacteria in the human gastrointestinal tract. In silico methods, mainly docking, assess the new structures of conjugates and the consequences of the interactions that are formed between proteins and polyphenols, as well as to predict their action in the body.
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Affiliation(s)
- Barbara Wróblewska
- Institute of Animal Reproduction and Food Research, Polish Academy of Science, 10-748 Olsztyn, Poland; (A.K.); (K.W.)
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Korotchenko E, Schießl V, Scheiblhofer S, Schubert M, Dall E, Joubert IA, Strandt H, Neuper T, Sarajlic M, Bauer R, Geppert M, Joedicke D, Wildner S, Schaller S, Winkler S, Gadermaier G, Horejs‐Hoeck J, Weiss R. Laser-facilitated epicutaneous immunotherapy with hypoallergenic beta-glucan neoglycoconjugates suppresses lung inflammation and avoids local side effects in a mouse model of allergic asthma. Allergy 2021; 76:210-222. [PMID: 32621318 PMCID: PMC7818228 DOI: 10.1111/all.14481] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/28/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022]
Abstract
Background Allergen‐specific immunotherapy via the skin targets a tissue rich in antigen‐presenting cells, but can be associated with local and systemic side effects. Allergen‐polysaccharide neoglycogonjugates increase immunization efficacy by targeting and activating dendritic cells via C‐type lectin receptors and reduce side effects. Objective We investigated the immunogenicity, allergenicity, and therapeutic efficacy of laminarin‐ovalbumin neoglycoconjugates (LamOVA). Methods The biological activity of LamOVA was characterized in vitro using bone marrow‐derived dendritic cells. Immunogenicity and therapeutic efficacy were analyzed in BALB/c mice. Epicutaneous immunotherapy (EPIT) was performed using fractional infrared laser ablation to generate micropores in the skin, and the effects of LamOVA on blocking IgG, IgE, cellular composition of BAL, lung, and spleen, lung function, and T‐cell polarization were assessed. Results Conjugation of laminarin to ovalbumin reduced its IgE binding capacity fivefold and increased its immunogenicity threefold in terms of IgG generation. EPIT with LamOVA induced significantly higher IgG levels than OVA, matching the levels induced by s.c. injection of OVA/alum (SCIT). EPIT was equally effective as SCIT in terms of blocking IgG induction and suppression of lung inflammation and airway hyperresponsiveness, but SCIT was associated with higher levels of therapy‐induced IgE and TH2 cytokines. EPIT with LamOVA induced significantly lower local skin reactions during therapy compared to unconjugated OVA. Conclusion Conjugation of ovalbumin to laminarin increased its immunogenicity while at the same time reducing local side effects. LamOVA EPIT via laser‐generated micropores is safe and equally effective compared to SCIT with alum, without the need for adjuvant.
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Affiliation(s)
| | - Viktoria Schießl
- Department of Biosciences University of Salzburg Salzburg Austria
| | | | - Mario Schubert
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Elfriede Dall
- Department of Biosciences University of Salzburg Salzburg Austria
| | | | - Helen Strandt
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Theresa Neuper
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Muamera Sarajlic
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Renate Bauer
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Mark Geppert
- Department of Biosciences University of Salzburg Salzburg Austria
| | - David Joedicke
- Research and Development University of Applied Biosciences Upper Austria Hagenberg Austria
| | - Sabrina Wildner
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Susanne Schaller
- Research and Development University of Applied Biosciences Upper Austria Hagenberg Austria
| | - Stephan Winkler
- Research and Development University of Applied Biosciences Upper Austria Hagenberg Austria
| | | | | | - Richard Weiss
- Department of Biosciences University of Salzburg Salzburg Austria
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Robledo-Retana T, Mani BM, Teran LM. Ligustrum pollen: New insights into allergic disease. World Allergy Organ J 2020; 13:100104. [PMID: 32055279 PMCID: PMC7005548 DOI: 10.1016/j.waojou.2020.100104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 11/28/2019] [Accepted: 01/15/2020] [Indexed: 11/29/2022] Open
Abstract
Respiratory allergies are important medical conditions because they affect nearly 20% of the population worldwide, with higher prevalence in industrialized cities. Aeroallergens such as pollen are responsible for up to 40% of respiratory allergies. The pollen from Ligustrum (privet hedge) is a great source of inhalant allergens associated with allergic respiratory diseases around the world. However, it has been underestimated as a sensitization factor. Interestingly, over the last few years a number of novel allergens have been identified from Ligustrum using immunoproteomics technologies. Cross-linking of IgE and Ligustrum allergens could lead to the rapid release of inflammatory mediators by mast cells and basophils. These will promote a late response characterized by activation of T cells and overproduction of Th2 cytokines such as IL-4, IL-5, IL-9, and IL-13. These inflammatory changes cause respiratory diseases like asthma and allergic rhinitis in sensitized subjects. Here, we review Ligustrum pollen allergens and focus on their clinical and immunological significance in allergic disease as well as the use of hypoallergenic derivatives in personalized therapy.
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Affiliation(s)
- Tania Robledo-Retana
- Biochemistry Department, Queen Mary University of London, Mile End Rd, London, E1 4NS, UK
| | - Blessy M Mani
- Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, C.P. 14080, Mexico City, Mexico
| | - Luis M Teran
- Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, C.P. 14080, Mexico City, Mexico
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Soh WT, Aglas L, Mueller GA, Gilles S, Weiss R, Scheiblhofer S, Huber S, Scheidt T, Thompson PM, Briza P, London RE, Traidl‐Hoffmann C, Cabrele C, Brandstetter H, Ferreira F. Multiple roles of Bet v 1 ligands in allergen stabilization and modulation of endosomal protease activity. Allergy 2019; 74:2382-2393. [PMID: 31230350 PMCID: PMC6910946 DOI: 10.1111/all.13948] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 04/30/2019] [Indexed: 12/21/2022]
Abstract
Background Over 100 million people worldwide suffer from birch pollen allergy. Bet v 1 has been identified as the major birch pollen allergen. However, the molecular mechanisms of birch allergic sensitization, including the roles of Bet v 1 and other components of the birch pollen extract, remain incompletely understood. Here, we examined how known birch pollen–derived molecules influence the endolysosomal processing of Bet v 1, thereby shaping its allergenicity. Methods We analyzed the biochemical and immunological interaction of ligands with Bet v 1. We then investigated the proteolytic processing of Bet v 1 by endosomal extracts in the presence and absence of ligands, followed by a detailed kinetic analysis of Bet v 1 processing by individual endolysosomal proteases as well as the T‐cell epitope presentation in BMDCs. Results We identified E1 phytoprostanes as novel Bet v 1 ligands. Pollen‐derived ligands enhanced the proteolytic resistance of Bet v 1, affecting degradation kinetics and preferential cleavage sites of the endolysosomal proteases cathepsin S and legumain. E1 phytoprostanes exhibited a dual role by stabilizing Bet v 1 and inhibiting cathepsin protease activity. Conclusion Bet v 1 can serve as a transporter of pollen‐derived, bioactive compounds. When carried to the endolysosome, such compounds can modulate the proteolytic activity, including its processing by cysteine cathepsins. We unveil a paradigm shift from an allergen‐centered view to a more systemic view that includes the host endolysosomal enzymes.
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Affiliation(s)
- Wai Tuck Soh
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Lorenz Aglas
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Geoffrey A. Mueller
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory National Institute of Environmental Health Sciences, National Institutes of Health Research Triangle Park North Carolina
| | - Stefanie Gilles
- Institute of Environmental Medicine UNIKA‐T, Technical University Munich and Helmholtz Zentrum München Augsburg Germany
- Christine‐Kühne‐Center for Allergy Research and Education (CK CARE) Davos Switzerland
| | - Richard Weiss
- Department of Biosciences University of Salzburg Salzburg Austria
| | | | - Sara Huber
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Tamara Scheidt
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Peter M. Thompson
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory National Institute of Environmental Health Sciences, National Institutes of Health Research Triangle Park North Carolina
| | - Peter Briza
- Department of Biosciences University of Salzburg Salzburg Austria
| | - Robert E. London
- Department of Health and Human Services, Genome Integrity and Structural Biology Laboratory National Institute of Environmental Health Sciences, National Institutes of Health Research Triangle Park North Carolina
| | - Claudia Traidl‐Hoffmann
- Institute of Environmental Medicine UNIKA‐T, Technical University Munich and Helmholtz Zentrum München Augsburg Germany
- Christine‐Kühne‐Center for Allergy Research and Education (CK CARE) Davos Switzerland
| | - Chiara Cabrele
- Department of Biosciences University of Salzburg Salzburg Austria
| | | | - Fatima Ferreira
- Department of Biosciences University of Salzburg Salzburg Austria
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Verhoeckx K, Bøgh KL, Dupont D, Egger L, Gadermaier G, Larré C, Mackie A, Menard O, Adel-Patient K, Picariello G, Portmann R, Smit J, Turner P, Untersmayr E, Epstein MM. The relevance of a digestibility evaluation in the allergenicity risk assessment of novel proteins. Opinion of a joint initiative of COST action ImpARAS and COST action INFOGEST. Food Chem Toxicol 2019; 129:405-423. [PMID: 31063834 DOI: 10.1016/j.fct.2019.04.052] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/25/2019] [Accepted: 04/27/2019] [Indexed: 01/09/2023]
Abstract
The current allergenicity assessment of novel proteins is based on the EFSA GMO guidance. Recently, EFSA launched a new guidance document on allergenicity assessment of GM plants (2017). This document describes, amongst other topics, the new scientific and regulatory developments on in vitro protein digestibility tests. The EFSA GMO Panel stated that for in vitro protein digestibility tests, additional investigations are needed before any additional recommendation in the form of guidance can be provided. To this end, an interim phase is considered necessary to evaluate the revisions to the in vitro gastrointestinal digestion test, proposed by EFSA. This prompted the establishment of a joint workshop through two COST Action networks: COST Action ImpARAS and COST Acton INFOGEST. In 2017, a workshop was organised to discuss the relevance of digestion in allergenicity risk assessment and how to potentially improve the current methods and readouts. The outcome of the workshop is that there is no rationale for a clear readout that is predictive for allergenicity and we suggest to omit the digestion test from the allergenicity assessment strategy for now, and put an effort into filling the knowledge gaps as summarized in this paper first.
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Affiliation(s)
| | - Katrine Lindholm Bøgh
- National Food Institute, Technical University of Denmark, DK-2800, Kgs. Lyngby, Denmark.
| | | | - Lotti Egger
- Agroscope, Schwarzenburgstr. 161, 3003, Bern, Charlotte, Switzerland.
| | - Gabriele Gadermaier
- University of Salzburg, Department of Biosciences, Hellbrunnerstraße 34, 5020 Salzburg, Austria.
| | - Colette Larré
- INRA UR1268 BIA, Rue de la Géraudière, BP 71627, 44316 Nantes, France.
| | - Alan Mackie
- School of Food Science and Nutrition, University of Leeds, LS2 9JT, UK.
| | | | - Karine Adel-Patient
- UMR Service de Pharmacologie et Immunoanalyse, Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, F-91191, Gif-sur-Yvette Cedex, France.
| | | | - Reto Portmann
- Agroscope, Schwarzenburgstr. 161, 3003 Bern, Switzerland.
| | - Joost Smit
- Institute of Risk Assessment Sciences, Utrecht University, Yalelaan 104, 3584CM, Utrecht, the Netherlands.
| | - Paul Turner
- Section of Paediatrics, Imperial College London, London, United Kingdom.
| | - Eva Untersmayr
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
| | - Michelle M Epstein
- Department of Dermatology, Experimental Allergy Laboratory, Medical University of Vienna, Waehringer Guertel 18-20 room 4P9.02, 1090, Vienna, Austria.
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Pablos I, Eichhorn S, Machado Y, Briza P, Neunkirchner A, Jahn-Schmid B, Wildner S, Soh WT, Ebner C, Park JW, Pickl WF, Arora N, Vieths S, Ferreira F, Gadermaier G. Distinct epitope structures of defensin-like proteins linked to proline-rich regions give rise to differences in their allergenic activity. Allergy 2018; 73:431-441. [PMID: 28960341 PMCID: PMC5771466 DOI: 10.1111/all.13298] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2017] [Indexed: 01/17/2023]
Abstract
Background Art v 1, Amb a 4, and Par h 1 are allergenic defensin‐polyproline–linked proteins present in mugwort, ragweed, and feverfew pollen, respectively. We aimed to investigate the physicochemical and immunological features underlying the different allergenic capacities of those allergens. Methods Recombinant defensin‐polyproline–linked proteins were expressed in E. coli and physicochemically characterized in detail regarding identity, secondary structure, and aggregation status. Allergenic activity was assessed by mediator releases assay, serum IgE reactivity, and IgE inhibition ELISA using sera of patients from Austria, Canada, and Korea. Endolysosomal protein degradation and T‐cell cross‐reactivity were studied in vitro. Results Despite variations in the proline‐rich region, similar secondary structure elements were observed in the defensin‐like domains. Seventy‐four percent and 52% of the Austrian and Canadian patients reacted to all three allergens, while Korean patients were almost exclusively sensitized to Art v 1. This was reflected by IgE inhibition assays demonstrating high cross‐reactivity for Austrian, medium for Canadian, and low for Korean sera. In a subgroup of patients, IgE reactivity toward structurally altered Amb a 4 and Par h 1 was not changed suggesting involvement of linear epitopes. Immunologically relevant endolysosomal stability of the defensin‐like domain was limited to Art v 1 and no T‐cell cross‐reactivity with Art v 125‐36 was observed. Conclusions Despite structural similarity, different IgE‐binding profiles and proteolytic processing impacted the allergenic capacity of defensin‐polyproline–linked molecules. Based on the fact that Amb a 4 demonstrated distinct IgE‐binding epitopes, we suggest inclusion in molecule‐based allergy diagnosis.
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Affiliation(s)
- I. Pablos
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
| | - S. Eichhorn
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
| | - Y. Machado
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
| | - P. Briza
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
| | - A. Neunkirchner
- Center for Pathophysiology, Infectiology and Immunology; Institute of Immunology; Medical University of Vienna; Vienna Austria
| | - B. Jahn-Schmid
- Department of Pathophysiology and Allergy Research; Medical University of Vienna; Vienna Austria
| | - S. Wildner
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
- Christian Doppler Laboratory for Biosimilar Characterization; University of Salzburg; Salzburg Austria
| | - W. T. Soh
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
| | - C. Ebner
- Allergy Clinic Reumannplatz; Vienna Austria
| | - J.-W. Park
- Department of Internal Medicine and Institute of Allergy; Yonsei University College of Medicine; Seoul Korea
| | - W. F. Pickl
- Center for Pathophysiology, Infectiology and Immunology; Institute of Immunology; Medical University of Vienna; Vienna Austria
| | - N. Arora
- Allergy and Immunology Section; CSIR-Institute of Genomic and Integrative Biology; Delhi India
| | - S. Vieths
- Division of Allergology; Paul-Ehrlich-Institut; Langen Germany
| | - F. Ferreira
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
| | - G. Gadermaier
- Division of Allergy and Immunology; Department of Molecular Biology; University of Salzburg; Salzburg Austria
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