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Kanchan K, Grinek S, Bahnson HT, Ruczinski I, Shankar G, Larson D, Du Toit G, Barnes KC, Sampson HA, Suarez-Farinas M, Lack G, Nepom GT, Cerosaletti K, Mathias RA. HLA alleles and sustained peanut consumption promote IgG4 responses in subjects protected from peanut allergy. J Clin Invest 2022; 132:e152070. [PMID: 34981778 PMCID: PMC8718139 DOI: 10.1172/jci152070] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/28/2021] [Indexed: 11/18/2022] Open
Abstract
We investigated the interplay between genetics and oral peanut protein exposure in the determination of the immunological response to peanut using the targeted intervention in the LEAP clinical trial. We identified an association between peanut-specific IgG4 and HLA-DQA1*01:02 that was only observed in the presence of sustained oral peanut protein exposure. The association between IgG4 and HLA-DQA1*01:02 was driven by IgG4 specific for the Ara h 2 component. Once peanut consumption ceased, the association between IgG4-specific Ara h 2 and HLA-DQA1*01:02 was attenuated. The association was validated by observing expanded IgG4-specific epitopes in people who carried HLA-DQA1*01:02. Notably, we confirmed the previously reported associations with HLA-DQA1*01:02 and peanut allergy risk in the absence of oral peanut protein exposure. Interaction between HLA and presence or absence of exposure to peanut in an allergen- and epitope-specific manner implicates a mechanism of antigen recognition that is fundamental to driving immune responses related to allergy risk or protection.
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Affiliation(s)
- Kanika Kanchan
- Division of Allergy and Clinical Immunology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Stepan Grinek
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Henry T. Bahnson
- Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA
- The Immune Tolerance Network, Bethesda, Maryland, USA
| | - Ingo Ruczinski
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Gautam Shankar
- Division of Allergy and Clinical Immunology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - David Larson
- The Immune Tolerance Network, Bethesda, Maryland, USA
| | - George Du Toit
- The Department of Pediatric Allergy, Division of Asthma, Allergy and Lung Biology, King’s College London, and Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Kathleen C. Barnes
- The Department of Medicine, University of Colorado, Anschutz, Colorado, USA
| | | | - Mayte Suarez-Farinas
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gideon Lack
- The Department of Pediatric Allergy, Division of Asthma, Allergy and Lung Biology, King’s College London, and Guy’s and St. Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Gerald T. Nepom
- Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA
- The Immune Tolerance Network, Bethesda, Maryland, USA
| | - Karen Cerosaletti
- Benaroya Research Institute at Virginia Mason, Seattle, Washington, USA
| | - Rasika A. Mathias
- Division of Allergy and Clinical Immunology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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Achour J, Guinot M, Guillon B, Kapel R, Galet O, Adel‐Patient K, Hazebrouck S, Bernard H. Sensitization Potency of Sunflower Seed Protein in a Mouse Model: Identification of 2S-Albumins More Allergenic Than SFA-8. Mol Nutr Food Res 2021; 65:e2100369. [PMID: 34331387 PMCID: PMC9285957 DOI: 10.1002/mnfr.202100369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/23/2021] [Indexed: 11/12/2022]
Abstract
SCOPE Food allergy to sunflower seed (SFS) protein is not frequent and only non-specific lipid transfert protein (nsLTP) Hel a 3 is officially recognized as a food allergen. Out of the eleven seed storage 2S-albumins (SESA) detected in SFS, only SFA-8 allergenicity has been investigated so far. The study aimed then to evaluate SFS protein allergenicity and particularly, to compare the sensitization potency of SESA in a mouse model. METHODS AND RESULTS The most abundant SESA and nsLTP were isolated from SFS through a combination of chromatographic methods. Purified proteins were then used to measure specific IgG1 and IgE responses in BALB/c mice orally sensitized to different SFS protein isolates. The study, thus, confirmed the allergenicity of SFA-8 and Hel a 3 but mice were also highly sensitized to other SESA such as SESA2-1 or SESA20-2. Furthermore, competitive inhibition of IgE-binding revealed that SFA-8 IgE-reactivity was due to cross-reactivity with other SESA. 11S-globulins were weakly immunogenic and were rapidly degraded in an in vitro model of gastroduodenal digestion. In contrast, Hel a 3, SESA2-1 and SFA-8 were more resistant to proteolysis and gastroduodenal digestion did not affect their IgE-reactivity. CONCLUSIONS SESA2-1 or SESA20-2 were more potent allergens than SFA-8 in this mouse model. Allergenicity of SESA must be now confirmed in SFS-allergic patients.
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Affiliation(s)
- Jihana Achour
- CEAINRAEDépartement Médicaments et Technologies pour la Santé (DMTS)/Service de Pharmacologie et d'ImmunoanalyseUniversité Paris‐SaclayGif‐sur‐YvetteFrance
| | - Marine Guinot
- CEAINRAEDépartement Médicaments et Technologies pour la Santé (DMTS)/Service de Pharmacologie et d'ImmunoanalyseUniversité Paris‐SaclayGif‐sur‐YvetteFrance
| | - Blanche Guillon
- CEAINRAEDépartement Médicaments et Technologies pour la Santé (DMTS)/Service de Pharmacologie et d'ImmunoanalyseUniversité Paris‐SaclayGif‐sur‐YvetteFrance
| | - Romain Kapel
- Laboratoire Réactions et Génie des ProcédésCNRSLRGPUniversité de LorraineNancyFrance
| | | | - Karine Adel‐Patient
- CEAINRAEDépartement Médicaments et Technologies pour la Santé (DMTS)/Service de Pharmacologie et d'ImmunoanalyseUniversité Paris‐SaclayGif‐sur‐YvetteFrance
| | - Stéphane Hazebrouck
- CEAINRAEDépartement Médicaments et Technologies pour la Santé (DMTS)/Service de Pharmacologie et d'ImmunoanalyseUniversité Paris‐SaclayGif‐sur‐YvetteFrance
| | - Hervé Bernard
- CEAINRAEDépartement Médicaments et Technologies pour la Santé (DMTS)/Service de Pharmacologie et d'ImmunoanalyseUniversité Paris‐SaclayGif‐sur‐YvetteFrance
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Jambari NN, Liddell S, Martinez-Pomares L, Alcocer MJC. Effect of O-linked glycosylation on the antigenicity, cellular uptake and trafficking in dendritic cells of recombinant Ber e 1. PLoS One 2021; 16:e0249876. [PMID: 33914740 PMCID: PMC8084162 DOI: 10.1371/journal.pone.0249876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 03/29/2021] [Indexed: 11/18/2022] Open
Abstract
Ber e 1, a major Brazil nut allergen, has been successfully produced in the yeast Pichia pastoris expression system as homogenous recombinant Ber e 1 (rBer e 1) with similar physicochemical properties and identical immunoreactivity to its native counterpart, nBer e 1. However, O-linked glycans was detected on the P.pastoris-derived rBer e 1, which is not naturally present in nBer e 1, and may contribute to the allergic sensitisation. In this study, we addressed the glycosylation differences between P. pastoris-derived recombinant Ber e 1 and its native counterparts. We also determined whether this fungal glycosylation could affect the antigenicity and immunogenicity of the rBer e 1 by using dendritic cells (DC) as an immune cell model due to their role in modulating the immune response. We identified that the glycosylation occurs at Ser96, Ser101 and Ser110 on the large chain and Ser19 on the small polypeptide chain of rBer e 1 only. The glycosylation on rBer e 1 was shown to elicit varying degree of antigenicity by binding to different combination of human leukocyte antigens (HLA) at different frequencies compared to nBer e 1 when tested using human DC-T cell assay. However, both forms of Ber e 1 are weak immunogens based from their low response indexes (RI). Glycans present on rBer e 1 were shown to increase the efficiency of the protein recognition and internalization by murine bone marrow-derived dendritic cells (bmDC) via C-type lectin receptors, particularly the mannose receptor (MR), compared to the non-glycosylated nBer e 1 and SFA8, a weak allergenic 2S albumin protein from sunflower seed. Binding of glycosylated rBer e 1 to MR alone was found to not induce the production of IL-10 that modulates bmDC to polarise Th2 cell response by suppressing IL-12 production and DC maturation. Our findings suggest that the O-linked glycosylation by P. pastoris has a small but measurable effect on the in vitro antigenicity of the rBer e 1 compared to its non-glycosylated counterpart, nBer e 1, and thus may influence its applications in diagnostics and immunotherapy.
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Affiliation(s)
- Nuzul N. Jambari
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Laboratory of Food Safety and Food Integrity (FOSFI), Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Susan Liddell
- Division of Animal Science, School of Biosciences, University of Nottingham, Loughborough, United Kingdom
| | - Luisa Martinez-Pomares
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Marcos J. C. Alcocer
- Division of Food Sciences, School of Biosciences, University of Nottingham, Loughborough, United Kingdom
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Mattar H, Padfield P, Simpson A, Mills ENC. The impact of a baked muffin matrix on the bioaccessibility and IgE reactivity of egg and peanut allergens. Food Chem 2021; 362:129879. [PMID: 34118511 DOI: 10.1016/j.foodchem.2021.129879] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/22/2021] [Accepted: 04/09/2021] [Indexed: 11/20/2022]
Abstract
Baked matrices, such as muffin, may help to promote tolerance to food allergens by modifying allergen structure, digestibility, and capacity to stimulate the immune responses. However, the impact of the muffin matrix on the bioaccessibility of allergens in the gastrointestinal tract is not well understood. Muffin containing egg and peanut was subjected to in vitro oral-gastro-duodenal digestion. During gastric digestion, the majority of the egg allergen Gal d 2 and the peanut allergens Ara h 1 and 3 were not bioaccessible. Subsequent duodenal digestion increased allergen bioaccessibility with Gal d 2 and the peanut allergen Ara h 2 proving highly resistant to digestion. The IgE reactivity of bioaccessible peanut allergens was retained to a greater extent than that of egg allergens after oral-gastric digestion. The starch and gluten-rich muffin matrix modifies allergen bioaccessiblity in a manner more similar to baked matrices such as bread, than low water activity matrices such as cookies.
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Affiliation(s)
- Hadeer Mattar
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK
| | - Phil Padfield
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK
| | - Angela Simpson
- School of Biological Sciences, Manchester Academic Health Sciences Centre, Wythenshawe Hospital Manchester University NHS Foundation Trust, M23 9LT Manchester, UK
| | - E N Clare Mills
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK.
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Smits M, Meijerink M, Le TM, Knulst A, de Jong A, Caspers MPM, Lima ES, Babé L, Ladics G, McClain S, Houben G, Verhoeckx K. Predicting the allergenicity of legume proteins using a PBMC gene expression assay. BMC Immunol 2021; 22:27. [PMID: 33849432 PMCID: PMC8042678 DOI: 10.1186/s12865-021-00415-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 03/23/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Food proteins differ in their allergenic potential. Currently, there is no predictive and validated bio-assay to evaluate the allergenicity of novel food proteins. The objective of this study was to investigate the potential of a human peripheral blood mononuclear cell (PBMC) gene expression assay to identify biomarkers to predict the allergenicity of legume proteins. RESULTS PBMCs from healthy donors were exposed to weakly and strongly allergenic legume proteins (2S albumins, and 7S and 11S globulins from white bean, soybean, peanut, pea and lupine) in three experiments. Possible biomarkers for allergenicity were investigated by exposing PBMCs to a protein pair of weakly (white bean) and strongly allergenic (soybean) 7S globulins in a pilot experiment. Gene expression was measured by RNA-sequencing and differentially expressed genes were selected as biomarkers. 153 genes were identified as having significantly different expression levels to the 7S globulin of white bean compared to soybean. Inclusion of multiple protein pairs from 2S albumins (lupine and peanut) and 7S globulins (white bean and soybean) in a larger study, led to the selection of CCL2, CCL7, and RASD2 as biomarkers to distinguish weakly from strongly allergenic proteins. The relevance of these three biomarkers was confirmed by qPCR when PBMCs were exposed to a larger panel of weakly and strongly allergenic legume proteins (2S albumins, and 7S and 11S globulins from white bean, soybean, peanut, pea and lupine). CONCLUSIONS The PBMC gene expression assay can potentially distinguish weakly from strongly allergenic legume proteins within a protein family, though it will be challenging to develop a generic method for all protein families from plant and animal sources. Graded responses within a protein family might be of more value in allergenicity prediction instead of a yes or no classification.
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Affiliation(s)
- Mark Smits
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands
- Center of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marjolein Meijerink
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands.
| | - Thuy-My Le
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands
- Center of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - André Knulst
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands
- Center of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Aard de Jong
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
| | | | - Everton Souto Lima
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
| | - Lilia Babé
- DuPont Nutrition and Biosciences, Palo Alto, CA, USA
| | | | - Scott McClain
- Formerly, Syngenta Crop Protection, LLC, 754 Research Triangle Park, Durham, USA
| | - Geert Houben
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands
- Center of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kitty Verhoeckx
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht, The Netherlands
- Center of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
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Dreskin SC, Koppelman SJ, Andorf S, Nadeau KC, Kalra A, Braun W, Negi SS, Chen X, Schein CH. The importance of the 2S albumins for allergenicity and cross-reactivity of peanuts, tree nuts, and sesame seeds. J Allergy Clin Immunol 2021; 147:1154-1163. [PMID: 33217410 PMCID: PMC8035160 DOI: 10.1016/j.jaci.2020.11.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022]
Abstract
Allergies to peanuts, tree nuts, and sesame seeds are among the most important food-related causes of anaphylaxis. Important clinical questions include: Why is there a variable occurrence of coallergy among these foods and Is this immunologically mediated? The clinical and immunologic data summarized here suggest an immunologic basis for these coallergies that is based on similarities among the 2S albumins. Data from component resolved diagnostics have highlighted the relationship between IgE binding to these allergens and the presence of IgE-mediated food allergy. Furthermore, in vitro and in vivo experiments provide strong evidence that the 2S albumins are the most important allergens in peanuts for inducing an allergic effector response. Although the 2S albumins are diverse, they have a common disulfide-linked core with similar physicochemical properties that make them prime candidates to explain much of the observed coallergy among peanuts, tree nuts, and sesame seeds. The well-established frequency of cashew and pistachio nut coallergy (64%-100%) highlights how the structural similarities among their 2S albumins may account for observed clinical cross-reactivity. A complete understanding of the physicochemical properties of the 2S albumins in peanuts, tree nuts, and sesame seeds will enhance our ability to diagnose, treat, and ultimately prevent these allergies.
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Affiliation(s)
- Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo.
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Neb
| | - Sandra Andorf
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio; Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Kari C Nadeau
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Anjeli Kalra
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Catherine H Schein
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex; Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Tex.
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Thouvenot B, Roitel O, Tomasina J, Hilselberger B, Richard C, Jacquenet S, Codreanu-Morel F, Morisset M, Kanny G, Beaudouin E, Delebarre-Sauvage C, Olivry T, Favrot C, Bihain BE. Transcriptional frameshifts contribute to protein allergenicity. J Clin Invest 2020; 130:5477-5492. [PMID: 32634131 PMCID: PMC7524509 DOI: 10.1172/jci126275] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 07/01/2020] [Indexed: 01/07/2023] Open
Abstract
Transcription infidelity (TI) is a mechanism that increases RNA and protein diversity. We found that single-base omissions (i.e., gaps) occurred at significantly higher rates in the RNA of highly allergenic legumes. Transcripts from peanut, soybean, sesame, and mite allergens contained a higher density of gaps than those of nonallergens. Allergen transcripts translate into proteins with a cationic carboxy terminus depleted in hydrophobic residues. In mice, recombinant TI variants of the peanut allergen Ara h 2, but not the canonical allergen itself, induced, without adjuvant, the production of anaphylactogenic specific IgE (sIgE), binding to linear epitopes on both canonical and TI segments of the TI variants. The removal of cationic proteins from bovine lactoserum markedly reduced its capacity to induce sIgE. In peanut-allergic children, the sIgE reactivity was directed toward both canonical and TI segments of Ara h 2 variants. We discovered 2 peanut allergens, which we believe to be previously unreported, because of their RNA-DNA divergence gap patterns and TI peptide amino acid composition. Finally, we showed that the sIgE of children with IgE-negative milk allergy targeted cationic proteins in lactoserum. We propose that it is not the canonical allergens, but their TI variants, that initiate sIgE isotype switching, while both canonical and TI variants elicit clinical allergic reactions.
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Affiliation(s)
| | | | | | | | | | | | - Françoise Codreanu-Morel
- Unité Nationale d’Immunologie et d’Allergologie, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Martine Morisset
- Unité d’Allergologie, Département de Pneumologie, Centre Hospitalier Universitaire Angers, Angers, France
| | - Gisèle Kanny
- Service de Médecine Interne, Immunologie Clinique et Allergologie, Hôpitaux de Brabois, Centre Hospitalier Universitaire de Nancy, Vandœuvre-lès-Nancy, France
| | - Etienne Beaudouin
- Unité d’Allergologie, Centre Hospitalier Régional de Metz, Metz, France
| | - Christine Delebarre-Sauvage
- Allergology Center Saint-Vincent de Paul Hospital, Groupe Hospitalier de l’Institut Catholique de Lille, Lille, France
| | - Thierry Olivry
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Claude Favrot
- Clinic for Small Animal Internal Medicine, University of Zurich, Zurich, Switzerland
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Storni F, Cabral-Miranda G, Roesti E, Zha L, Engeroff P, Zeltins A, Cragg M, Vogel M, Bachmann MF. A Single Monoclonal Antibody against the Peanut Allergen Ara h 2 Protects against Systemic and Local Peanut Allergy. Int Arch Allergy Immunol 2020; 181:334-341. [PMID: 32155619 PMCID: PMC7265771 DOI: 10.1159/000505917] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 12/27/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Peanut allergy is the most prevalent and dangerous food allergy. Peanuts consist of a large number of different allergens and peanut-allergic patients are frequently sensitized to multiple allergens. Hence, conventional desensitization approaches aim at targeting as many allergens as possible. METHODS The monoclonal anti-Ara h 2 antibody (mAb) was produced by hybridoma cells derived from WT BALB/c mice after immunization with a vaccine based on virus-like particles coupled to Ara h 2. BALB/c mice were sensitized intraperitoneally with peanut extract absorbed to alum and mAbs were applied i.v. Challenge was performed the next day with the whole peanut extract intravenously and via skin prick test. RESULTS Here we show in peanut-allergic mice that a single high-affinity mAb specific for Ara h 2 is able to block systemic and local allergic reactions induced by the complex peanut extract. We confirm in vitro binding of the mAb to the inhibitory low-affinity FcγRIIb receptor using a sensitive biosensor and demonstrate in vivo that protection was dependent on FcγRIIb. CONCLUSION A single mAb specific for Ara h 2 is able to improve local and systemic allergic symptoms induced by the whole allergen mixture.
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Affiliation(s)
- Federico Storni
- Immunology, RIA, Inselspital, University of Bern, Bern, Switzerland,
- Department of BioMedical Research, University of Bern, Bern, Switzerland,
- Department of Visceral Surgery and Medicine, University Hospital of Bern, Bern, Switzerland,
| | - Gustavo Cabral-Miranda
- Immunology, RIA, Inselspital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Elisa Roesti
- Immunology, RIA, Inselspital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Lisha Zha
- International Immunology Center of Anhui Agricultural Center, Anhui, China
| | - Paul Engeroff
- Immunology, RIA, Inselspital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Andris Zeltins
- Latvian Biomedical Research and Study Centre (BRSC), Riga, Latvia
| | - Mark Cragg
- Antibody and Vaccine Group, Centre for Cancer Immunology, Cancer Sciences Unit, Faculty of Medicine, General Hospital, University of Southampton, Southampton, United Kingdom
| | - Monique Vogel
- Immunology, RIA, Inselspital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin F Bachmann
- Immunology, RIA, Inselspital, University of Bern, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
- Nuffield Department of Medicine, Centre for Cellular and Molecular Physiology (CCMP), The Jenner Institute, University of Oxford, Oxford, United Kingdom
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9
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Ren L, Wu Z, Zhang Y, Li K, Yuan J, Li X, Yang A, Tong P, Chen H. Polyphenol-oxidase-catalyzed cross-linking of Ara h 2: reaction sites and effect on structure and allergenicity. J Sci Food Agric 2020; 100:308-314. [PMID: 31525267 DOI: 10.1002/jsfa.10040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 08/25/2019] [Accepted: 09/11/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Peanut is among the most common of food allergies, and one of its allergens is Ara h 2. A previous study revealed that this allergen was recognized by serum immunoglobulin E (IgE) in over 90% of a peanut-allergic patient population. Enzymatic cross-linking is a popular processing method used to tailor food functionality, such as antigenicity. RESULT The cross-linking reactions of Ara h 2 were catalyzed by polyphenol oxidase (PPO), and the relevant reaction sites were identified using mass spectrometry and StavroX software. Two pairs of intramolecular cross-linking peptides and two intermolecular cross-linking peptides were found. Intramolecular cross-linking was speculated to occur between ARG131 (amino acids 116-131) and TYR65 (amino acids 63-80) and between TYR60 (amino acids 56-62) and ARG92 (amino acids 92-102); the intermolecular cross-linking sites were ARG31 with TYR84 or TYR89 and TYR65 or TYR72 with ARG92 or ARG102 . Three out of four cross-linking peptides were found in α-helices, and destruction of this secondary structure resulted in a loose tertiary structure. Although seven linear allergen epitopes were involved in cross-linking, the IgE binding capacity of protein changed slightly, while its sensitization potential decreased in mouse model. CONCLUSION Exploring the structural change of Ara h 2 after cross-linking is beneficial in further understanding the influence of structure on sensitization. This result indicated the future possibility of precision processing on structure of proteins to improve their properties. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Linmei Ren
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Environment and Chemical Engineering, Nanchang University, Nanchang, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Food Science and Technology, Nanchang University, Nanchang, China
| | - Kun Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Hubei Provincial Key Lab for Quality and Safety of Traditional Chinese Medicine Health Food Jing Brand Bio-medicine Co Ltd, Huangshi, China
| | - Juanli Yuan
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
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10
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Ueberham E, Spiegel H, Havenith H, Rautenberger P, Lidzba N, Schillberg S, Lehmann J. Simplified Tracking of a Soy Allergen in Processed Food Using a Monoclonal Antibody-Based Sandwich ELISA Targeting the Soybean 2S Albumin Gly m 8. J Agric Food Chem 2019; 67:8660-8667. [PMID: 31298531 DOI: 10.1021/acs.jafc.9b02717] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Soybean allergens in food samples are currently detected in most cases using enzyme-linked immunosorbent assays (ELISAs) based on antibodies raised against bulk soybean proteins or specifically targeting soybean trypsin inhibitor, conglycinin, or glycinin. The various commercial ELISAs lack standardized reference material, and the results are often inaccurate because the antibodies cross-react with proteins from other legumes. Furthermore, the isolation of allergenic proteins involves laborious denaturing extraction conditions. To tackle these challenges, we have developed a novel sandwich ELISA based on monoclonal antibodies raised against the soybean 2S albumin Gly m 8 and a recombinant Gly m 8 reference protein with native-analogous characteristics. The antibodies do not cross-react with other legume proteins, and the extraordinary stability and solubility of Gly m 8 allows it to be extracted even from complex matrices after processing. The Gly m 8 ELISA therefore achieves greater specificity and reproducibility than current ELISA tests.
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Affiliation(s)
- Elke Ueberham
- Fraunhofer Institute for Cell Therapy and Immunology IZI , Perlickstraße 1 , 04103 Leipzig , Germany
| | - Holger Spiegel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , Forckenbeckstrasse 6 , 52074 Aachen , Germany
| | - Heide Havenith
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , Forckenbeckstrasse 6 , 52074 Aachen , Germany
| | - Paul Rautenberger
- Fraunhofer Institute for Cell Therapy and Immunology IZI , Perlickstraße 1 , 04103 Leipzig , Germany
| | - Norbert Lidzba
- Fraunhofer Institute for Cell Therapy and Immunology IZI , Perlickstraße 1 , 04103 Leipzig , Germany
| | - Stefan Schillberg
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME , Forckenbeckstrasse 6 , 52074 Aachen , Germany
| | - Jörg Lehmann
- Fraunhofer Institute for Cell Therapy and Immunology IZI , Perlickstraße 1 , 04103 Leipzig , Germany
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11
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Patil SU, Steinbrecher J, Calatroni A, Smith N, Ma A, Ruiter B, Virkud Y, Schneider M, Shreffler WG. Early decrease in basophil sensitivity to Ara h 2 precedes sustained unresponsiveness after peanut oral immunotherapy. J Allergy Clin Immunol 2019; 144:1310-1319.e4. [PMID: 31377342 DOI: 10.1016/j.jaci.2019.07.028] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/05/2019] [Accepted: 07/17/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND Only some patients with peanut allergy undergoing oral immunotherapy (OIT) achieve sustained clinical response. Basophil activation could provide a functional surrogate of efficacy. OBJECTIVE We hypothesized that changes in basophil sensitivity and area under the curve (AUC) to the immunodominant allergen Ara h 2 correlate with clinical responses to OIT. METHODS Children with peanut allergy aged 7 to 13 years were enrolled in a single-center, open-label peanut OIT trial. Levels of specific immunoglobulins were measured throughout OIT. Peripheral blood from multiple time points was stimulated in vitro with peanut allergens for flow cytometric assessment of the percentage of CD63hi activated basophils. RESULTS Twenty-two of 30 subjects were successfully treated with OIT; after avoidance, 9 achieved sustained unresponsiveness (SU), and 13 had transient desensitization (TD). Basophil sensitivity, measured by using the dose that induces 50% of the maximal basophil response, to Ara h 2 stimulation decreased from baseline in subjects with SU (after OIT, P = .0041; after avoidance, P = .0011). At 3 months of OIT, basophil sensitivity in subjects with SU decreased from baseline compared with that in subjects with TD (median, 18-fold vs 3-fold; P = .01), with a receiver operating characteristic of 0.84 and optimal fold change of 4.9. Basophil AUC to Ara h 2 was suppressed after OIT equally in subjects with SU and those with TD (P = .4). After avoidance, basophil AUC rebounded in subjects with TD but not those with SU (P < .001). Passively sensitized basophils suppressed with postavoidance SU plasma had a lower AUC than TD plasma (6.4% vs 38.9%, P = .03). CONCLUSIONS Early decreases in basophil sensitivity to Ara h 2 correlate with SU. Basophil AUC rebounds after avoidance in subjects with TD. Therefore, different aspects of basophil activation might be useful for monitoring of OIT efficacy.
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Affiliation(s)
- Sarita U Patil
- Food Allergy Center, Massachusetts General Hospital, Boston, Mass; Harvard Medical School, Boston, Mass; Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Boston, Mass; Food Allergy Science Initiative at Broad Institute at Massachusetts Institute of Technology and Harvard, Boston, Mass.
| | | | | | - Neal Smith
- Food Allergy Center, Massachusetts General Hospital, Boston, Mass
| | - Alex Ma
- Food Allergy Center, Massachusetts General Hospital, Boston, Mass
| | - Bert Ruiter
- Food Allergy Center, Massachusetts General Hospital, Boston, Mass; Harvard Medical School, Boston, Mass; Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Boston, Mass; Food Allergy Science Initiative at Broad Institute at Massachusetts Institute of Technology and Harvard, Boston, Mass
| | - Yamini Virkud
- Food Allergy Center, Massachusetts General Hospital, Boston, Mass; Harvard Medical School, Boston, Mass; Food Allergy Science Initiative at Broad Institute at Massachusetts Institute of Technology and Harvard, Boston, Mass
| | | | - Wayne G Shreffler
- Food Allergy Center, Massachusetts General Hospital, Boston, Mass; Harvard Medical School, Boston, Mass; Center for Immunology & Inflammatory Diseases, Massachusetts General Hospital, Boston, Mass; Food Allergy Science Initiative at Broad Institute at Massachusetts Institute of Technology and Harvard, Boston, Mass
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12
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Nihei M, Sato T, Horino S, Miura K. [SAFETY OF A THREE-LEVEL STEPWISE ORAL FOOD CHALLENGE FOR PEANUT ALLERGY]. Arerugi 2019; 68:851-856. [PMID: 31406081 DOI: 10.15036/arerugi.68.851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
BACKGROUND The present study aimed to assess the safety of a three-level stepwise oral food challenge (OFC) in patients with peanut allergy. METHODS This retrospective analysis reviewed laboratory test results and food allergy histories (obtained from medical records) of participants who underwent OFC using peanut butter for the first time at Miyagi Children's Hospital between January 2015 and December 2017. Total food dose was classified as follows: step 1, 0.1 g peanut butter; step 2, 0.5g peanut butter; and step 3, 3g peanut butter. RESULTS A total of 114 participants were included. OFC-positive rates were 52% (step 1), 35% (step 2), and 20% (step 3). Of the 41 OFC-positive participants, 1 required an intramuscular adrenaline injection during step 3. Peanut allergy history rates and peanut- and Ara h 2-specific immunoglobulin E (sIgE) titers were significantly higher during the low-dose step. CONCLUSION The three-level stepwise OFC with peanut butter is safe for patients with peanut allergy, as indicated by peanut- and Ara h 2-sIgE titers.
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Affiliation(s)
- Masato Nihei
- Department of Allergy, Miyagi Children's Hospital
| | - Taiki Sato
- Department of Allergy, Miyagi Children's Hospital
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13
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de Jong GAH, Jayasena S, Johnson P, Marsh J, Apostolovic D, van Hage M, Nordlee J, Baumert J, Taylor SL, Roucairol C, de Jongh H, Koppelman SJ. Purification and Characterization of Naturally Occurring Post-Translationally Cleaved Ara h 6, an Allergen That Contributes Substantially to the Allergenic Potency of Peanut. J Agric Food Chem 2018; 66:10855-10863. [PMID: 30284821 DOI: 10.1021/acs.jafc.8b03140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The 2S albumin Ara h 6 is one of the most important peanut allergens. A post-translationally cleaved Ara h 6 (pAra h 6) was purified from Virginia type peanuts, and the cleavage site was mapped using high-resolution mass spectrometry. Compared to intact Ara h 6, pAra h 6 lacks a 5-amino acid stretch, resembling amino acids 43-47 (UniProt accession number Q647G9) in the nonstructured loop. Consequently, pAra h 6 consists of two chains: an N-terminal chain of approximately 5 kDa and a C-terminal chain of approximately 9 kDa, held together by disulfide bonds. Intermediate post-translationally cleaved products, in which this stretch is cleaved yet still attached to one of the subunits, are also present. The secondary structure and immunoglobulin E (IgE) binding of pAra h 6 resembles that of intact Ara h 6, indicating that the loss of the nonstructured loop is not critical for maintaining the protein structure. Commercially available monoclonal and polyclonal immunoglobulin G (IgG) antibodies directed to Ara h 6 react with both intact Ara h 6 and pAra h 6, suggesting that the involved epitopes are not located in the area that is post-translationally cleaved. No differences between intact Ara h 6 and pAra h 6 in terms of IgE binding were found, suggesting that the area that is post-translationally cleaved is not involved in IgE epitopes either. For all main cultivars Runner, Virginia, Valencia, and Spanish, intact Ara h 6 and pAra h 6 occur in peanut at similar levels, indicating that pAra h 6 is a consistent and important contributor to the allergenic potency of peanut.
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Affiliation(s)
| | - Shyamali Jayasena
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Justin Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Danijela Apostolovic
- Immunology and Allergy Unit, Department of Medicine Solna , Karolinska Institutet , 171 77 Stockholm , Sweden
| | - Marianne van Hage
- Immunology and Allergy Unit, Department of Medicine Solna , Karolinska Institutet , 171 77 Stockholm , Sweden
| | - Julie Nordlee
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Joe Baumert
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Steve L Taylor
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Camille Roucairol
- DBV Technologies , Development Department , 92120 Montrouge , France
| | | | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
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14
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Koppelman SJ, Smits M, Tomassen M, de Jong GAH, Baumert J, Taylor SL, Witkamp R, Veldman RJ, Pieters R, Wichers H. Release of Major Peanut Allergens from Their Matrix under Various pH and Simulated Saliva Conditions-Ara h2 and Ara h6 Are Readily Bio-Accessible. Nutrients 2018; 10:E1281. [PMID: 30208580 PMCID: PMC6165493 DOI: 10.3390/nu10091281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/28/2018] [Accepted: 08/31/2018] [Indexed: 01/24/2023] Open
Abstract
The oral mucosa is the first immune tissue that encounters allergens upon ingestion of food. We hypothesized that the bio-accessibility of allergens at this stage may be a key determinant for sensitization. Light roasted peanut flour was suspended at various pH in buffers mimicking saliva. Protein concentrations and allergens profiles were determined in the supernatants. Peanut protein solubility was poor in the pH range between 3 and 6, while at a low pH (1.5) and at moderately high pHs (>8), it increased. In the pH range of saliva, between 6.5 and 8.5, the allergens Ara h2 and Ara h6 were readily released, whereas Ara h1 and Ara h3 were poorly released. Increasing the pH from 6.5 to 8.5 slightly increased the release of Ara h1 and Ara h3, but the recovery remained low (approximately 20%) compared to that of Ara h2 and Ara h6 (approximately 100% and 65%, respectively). This remarkable difference in the extraction kinetics suggests that Ara h2 and Ara h6 are the first allergens an individual is exposed to upon ingestion of peanut-containing food. We conclude that the peanut allergens Ara h2 and Ara h6 are quickly bio-accessible in the mouth, potentially explaining their extraordinary allergenicity.
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Affiliation(s)
- Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Mieke Smits
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
| | - Monic Tomassen
- Food & Biobased Research, Wageningen University and Research, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
| | | | - Joe Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Renger Witkamp
- Department of Human Nutrition, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Robert Jan Veldman
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
| | - Raymond Pieters
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
- Institute for Risk Assessment Sciences, Faculty of Veterinary Medicines, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, The Netherlands.
| | - Harry Wichers
- Food & Biobased Research, Wageningen University and Research, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
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15
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Shen M, Joshi AA, Vannam R, Dixit CK, Hamilton RG, Kumar CV, Rusling JF, Peczuh MW. Epitope-Resolved Detection of Peanut-Specific IgE Antibodies by Surface Plasmon Resonance Imaging. Chembiochem 2018; 19:199-202. [PMID: 29232483 PMCID: PMC5965296 DOI: 10.1002/cbic.201700513] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Indexed: 12/19/2022]
Abstract
Peanut allergy can be life-threatening and is mediated by allergen-specific immunoglobulin E (IgE) antibodies. Investigation of IgE antibody binding to allergenic epitopes can identify specific interactions underlying the allergic response. Here, we report a surface plasmon resonance imaging (SPRi) immunoassay for differentiating IgE antibodies by epitope-resolved detection. IgE antibodies were first captured by magnetic beads bearing IgE ϵ-chain-specific antibodies and then introduced into an SPRi array immobilized with epitopes from the major peanut allergen glycoprotein Arachis hypogaea h2 (Ara h2). Differential epitope responses were achieved by establishing a binding environment that minimized cross-reactivity while maximizing analytical sensitivity. IgE antibody binding to each Ara h2 epitope was distinguished and quantified from patient serum samples (10 μL each) in a 45 min assay. Excellent correlation of Ara h2-specific IgE values was found between ImmunoCAP assays and the new SPRi method.
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Affiliation(s)
- Min Shen
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Amit A Joshi
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Raghu Vannam
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Chandra K Dixit
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Robert G Hamilton
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Challa V Kumar
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - James F Rusling
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, 06032, USA
| | - Mark W Peczuh
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
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16
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Tontini C, Marinangeli L, Maiello N, Abbadessa S, Villalta D, Antonicelli L. Ara h 6 sensitization in peanut allergy: friend, foe or innocent bystander? Eur Ann Allergy Clin Immunol 2017; 49:18-21. [PMID: 28120602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The clinical role of Ara h 6 sensitization in peanut allergy is a current matter of debate. We investigated the role of Ara h 6 sensitization patterns in a sample of young adults from different Italian cities. Sera of 33 patients with specific IgE against Ara h 6 were selected. According to clinical symptoms upon peanut ingestion, patients were divided into severe reaction (SR) and mild-tolerant (MT) subgroups. While the SR group mainly showed sensitization patterns involving Ara h 2 and other major allergenic components, a previously undescribed association between Ara h 6 and Ara h 9 was found in the MT group. This pattern seems to be clustered in Mediterranean Italy and associated with Pru p 3 sensitization. This finding might shed a new light on the role of Ara h 6 sensitization in peanut allergy.
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Affiliation(s)
- C Tontini
- Dipartimento di Medicina Interna, U.O. Allergologia, Azienda Ospedaliero-Universitaria Ospedali Riuniti Ancona, Ancona, Italy. Phone: +39 071 596 5693 E-mail:
| | - L Marinangeli
- Dipartimento di Medicina Interna, U.O. Allergologia, Azienda Ospedaliero-Universitaria Ospedali Riuniti Ancona, Ancona, Italy
| | - N Maiello
- Dipartimento della Donna, del Bambino, Chirurgia Generale e Specialistica, Seconda Università di Napoli, Napoli, Italy
| | - S Abbadessa
- Dipartimento di Biochimica, Biofisica e Patologia Generale, Seconda Università di Napoli, Napoli, Italy
| | - D Villalta
- Allergologia ed Immunologia Clinica, Azienda Ospedaliera Santa Maria degli Angeli, Pordenone, Italy
| | - L Antonicelli
- Dipartimento di Medicina Interna, U.O. Allergologia, Azienda Ospedaliero-Universitaria Ospedali Riuniti Ancona, Ancona, Italy
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17
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van der Valk JPM, Schreurs MWJ, El Bouch R, Arends NJT, de Jong NW. Mono-sensitisation to peanut component Ara h 6: a case series of five children and literature review. Eur J Pediatr 2016; 175:1227-1234. [PMID: 27206507 PMCID: PMC5005383 DOI: 10.1007/s00431-016-2733-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 03/20/2016] [Accepted: 05/11/2016] [Indexed: 11/24/2022]
Abstract
UNLABELLED Here, we summarise the current clinical knowledge on Ara h 6 sensitisation and clinical relevance of this sensitisation pattern using five illustrative clinical cases. The literature search yielded a total of 166 papers, and an additional relevant article was found by 'snowballing'. A total of ten articles were considered relevant for this review. Most studies included patients with a sensitisation to Ara h 6 and cosensitisation to Ara h 2. Only three studies showed patients with a mono-sensitisation to Ara h 6. This illustrates that Ara h 6 mono-sensitisation has been neglected in literature. We present a case series of five children with sensitisation to peanut component Ara h 6. Only one of these five patients showed Ara h 8 cosensitivity. Three out of the five children had a positive double-blind placebo-controlled food challenge (DBPCFC), with moderate to strong reactions. CONCLUSION A mono-sensitisation to peanut component Ara h 6 is uncommon but can cause severe allergic reactions. Therefore, the determination of sIgE to Ara h 6 is warranted in patients with a suspected peanut allergy, especially in the absence of sensitisation to Ara h 1, 2, 3 and 9. WHAT IS KNOWN • Peanut allergy is common and can cause severe allergic reactions. • The diagnostics of peanut allergy has recently improved with the use of component resolved diagnosis What is new: • A mono-sensitisation to peanut component Ara h 6 is uncommon, but can cause severe allergic reactions • Determination of sIgE to Ara h 6 is warranted in patients with a suspected peanut allergy, especially in the absence of sensitisation to Ara h 1, 2, 3 and 9.
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Affiliation(s)
- J P M van der Valk
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands.
| | - M W J Schreurs
- Department of Immunology, Laboratory Medical Immunology, Erasmus MC, Rotterdam, The Netherlands
| | - R El Bouch
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands
| | - N J T Arends
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands
- Department of Paediatric Allergology, Diaconessenhuis Voorburg, Reinier de Graaf Group, Delft, The Netherlands
| | - N W de Jong
- Department of Internal Medicine, section of Allergology, Erasmus MC, Office Gk 323, P.O. box 2040, 3000CA, Rotterdam, The Netherlands
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18
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Wu Z, Lian J, Han Y, Zhou N, Li X, Yang A, Tong P, Chen H. Crosslinking of peanut allergen Ara h 2 by polyphenol oxidase: digestibility and potential allergenicity assessment. J Sci Food Agric 2016; 96:3567-3574. [PMID: 26597340 DOI: 10.1002/jsfa.7542] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/29/2015] [Accepted: 11/24/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND Peanut is one of the eight major food allergens. Its allergen, Ara h 2, can be recognized by over 90% of serum IgE samples from peanut-allergic patients. Therefore, reducing the allergenicity of Ara h 2 is especially important. RESULTS In the present study, polyphenol oxidase (PPO), a protein cross-linking reaction catalyst that acts on tyrosine residue, was used to modify Ara h 2. After crosslinking, the microstructure, digestibility, IgG binding capability and IgE binding capability of Ara h 2 were analyzed. Cross-linking decreased the potential allergenicity of Ara h 2 by masking the allergen epitope, while the antigenicity of Ara h 2 changed slightly. After crosslinking, the apparent diameter of Ara h 2 was altered from 300 to 1700 nm or 220 nm, indicating that polymerization could either be inter- or intramolecular. Regarding digestibility, crosslinked Ara h 2 was relatively more easily digested by gastric fluid compared with the untreated Ara h 2, but much more difficult in the intestinal fluid. CONCLUSION The crosslinking reaction catalyzed by PPO, as a non-thermal process, may be beneficial for avoiding food allergy. The reaction could mask allergen epitopes, decreasing the allergenicity of Ara h 2. © 2015 Society of Chemical Industry.
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Affiliation(s)
- Zhihua Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, 330047, China
| | - Jun Lian
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Yuanlong Han
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
- Jiangxi Synergy Pharmaceutical Co., Ltd, Fengxin, 330700, China
| | - Ningling Zhou
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
- Department of Food Science, Nanchang University, Nanchang, 330047, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, 330047, China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, 330047, China
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19
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Gregory JA, Shepley-McTaggart A, Umpierrez M, Hurlburt BK, Maleki SJ, Sampson HA, Mayfield SP, Berin MC. Immunotherapy using algal-produced Ara h 1 core domain suppresses peanut allergy in mice. Plant Biotechnol J 2016; 14:1541-50. [PMID: 26801740 PMCID: PMC5066676 DOI: 10.1111/pbi.12515] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 05/26/2023]
Abstract
Peanut allergy is an IgE-mediated adverse reaction to a subset of proteins found in peanuts. Immunotherapy aims to desensitize allergic patients through repeated and escalating exposures for several months to years using extracts or flours. The complex mix of proteins and variability between preparations complicates immunotherapy studies. Moreover, peanut immunotherapy is associated with frequent negative side effects and patients are often at risk of allergic reactions once immunotherapy is discontinued. Allergen-specific approaches using recombinant proteins are an attractive alternative because they allow more precise dosing and the opportunity to engineer proteins with improved safety profiles. We tested whether Ara h 1 and Ara h 2, two major peanut allergens, could be produced using chloroplast of the unicellular eukaryotic alga, Chlamydomonas reinhardtii. C. reinhardtii is novel host for producing allergens that is genetically tractable, inexpensive and easy to grow, and is able to produce more complex proteins than bacterial hosts. Compared to the native proteins, algal-produced Ara h 1 core domain and Ara h 2 have a reduced affinity for IgE from peanut-allergic patients. We further found that immunotherapy using algal-produced Ara h 1 core domain confers protection from peanut-induced anaphylaxis in a murine model of peanut allergy.
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Affiliation(s)
- James A Gregory
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ariel Shepley-McTaggart
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Michelle Umpierrez
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Barry K Hurlburt
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA
| | - Soheila J Maleki
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA
| | - Hugh A Sampson
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stephen P Mayfield
- Department of Biology, University of California San Diego, La Jolla, CA, USA
| | - M Cecilia Berin
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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20
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Han Y, Lin J, Bardina L, Grishina GA, Lee C, Seo WH, Sampson HA. What Characteristics Confer Proteins the Ability to Induce Allergic Responses? IgE Epitope Mapping and Comparison of the Structure of Soybean 2S Albumins and Ara h 2. Molecules 2016; 21:E622. [PMID: 27187334 PMCID: PMC6273924 DOI: 10.3390/molecules21050622] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/03/2016] [Accepted: 05/04/2016] [Indexed: 11/21/2022] Open
Abstract
Ara h 2, a peanut 2S albumin, is associated with severe allergic reactions, but a homologous protein, soybean 2S albumin, is not recognized as an important allergen. Structural difference between these proteins might explain this clinical discrepancy. Therefore, we mapped sequential epitopes and compared the structure of Ara h 2, Soy Al 1, and Soy Al 3 (Gly m 8) to confirm whether structural differences account for the discrepancy in clinical responses to these two proteins. Commercially synthesized peptides covering the full length of Ara h 2 and two soybean 2S albumins were analyzed by peptide microarray. Sera from 10 patients with peanut and soybean allergies and seven non-atopic controls were examined. The majority of epitopes in Ara h 2 identified by microarray are consistent with those identified previously. Several regions in the 2S albumins are weakly recognized by individual sera from different patients. A comparison of allergenic epitopes on peanut and soybean proteins suggests that loop-helix type secondary structures and some amino acids with a large side chain including lone electron pair, such as arginine, glutamine, and tyrosine, makes the peptides highly recognizable by the immune system. By utilizing the peptide microarray assay, we mapped IgE epitopes of Ara h 2 and two soybean 2S albumins. The use of peptide microarray mapping and analysis of the epitope characteristics may provide critical information to access the allergenicity of food proteins.
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Affiliation(s)
- Youngshin Han
- Division of Pediatric Allergy and Immunology and the Jaffe Food Allergy Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
- Department of Medical Science, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
| | - Jing Lin
- Division of Pediatric Allergy and Immunology and the Jaffe Food Allergy Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Ludmilla Bardina
- Division of Pediatric Allergy and Immunology and the Jaffe Food Allergy Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Galina A Grishina
- Division of Pediatric Allergy and Immunology and the Jaffe Food Allergy Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Chaeyoon Lee
- Department of Food Science and Engineering, Ewha Woman's University, Seoul 03760, Korea.
| | - Won Hee Seo
- Department of Pediatrics, Korea University College of Medicine, Seoul 02841, Korea.
| | - Hugh A Sampson
- Division of Pediatric Allergy and Immunology and the Jaffe Food Allergy Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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21
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Alves RC, Pimentel FB, Nouws HPA, Correr W, González-García MB, Oliveira MBPP, Delerue-Matos C. Detection of the peanut allergen Ara h 6 in foodstuffs using a voltammetric biosensing approach. Anal Bioanal Chem 2015; 407:7157-63. [PMID: 26164307 DOI: 10.1007/s00216-015-8879-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 05/27/2015] [Accepted: 06/24/2015] [Indexed: 12/13/2022]
Abstract
A voltammetric biosensor for Ara h 6 (a peanut allergen) detection in food samples was developed. Gold nanoparticle-modified screen-printed carbon electrodes were used to develop a sandwich-type immunoassay using two-monoclonal antibodies. The antibody-antigen interaction was detected through the electrochemical detection of enzymatically deposited silver. The immunosensor presented a linear range between 1 and 100 ng/ml, as well as high precision (inter-day RSD ≤9.8%) and accuracy (recoveries ≥96.7%). The detection and quantification limits were 0.27 and 0.88 ng/ml, respectively. It was possible to detect small levels of Ara h 6 in complex food matrices.
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Affiliation(s)
- Rita C Alves
- REQUIMTE/LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida 431, 4200-072, Porto, Portugal
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22
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Cabanillas B, Novak N. Allergic Reactions to Pine Nut: A Review. J Investig Allergol Clin Immunol 2015; 25:329-33. [PMID: 26727761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
Abstract
Pine nut is a nutrient-rich food with a beneficial impact on human health. The many bioactive constituents of pine nut interact synergistically to affect human physiology in a favorable way. However, pine nut can trigger dangerous allergic reactions. Severe anaphylactic reactions to pine nut accounted for most of the 45 cases reported in the scientific literature. Pine nut allergy seems to be characterized by low IgE cross-reactivity with other commonly consumed nuts and a high monosensitization rate. The present review provides updated information on allergic reactions to pine nut, molecular characterization of its allergens, and potential homologies with other nut allergens.
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23
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Mattison CP, Desormeaux WA, Wasserman RL, Yoshioka-Tarver M, Condon B, Grimm CC. Decreased immunoglobulin E (IgE) binding to cashew allergens following sodium sulfite treatment and heating. J Agric Food Chem 2014; 62:6746-6755. [PMID: 24926808 DOI: 10.1021/jf501117p] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Cashew nut and other nut allergies can result in serious and sometimes life-threatening reactions. Linear and conformational epitopes within food allergens are important for immunoglobulin E (IgE) binding. Methods that disrupt allergen structure can lower IgE binding and lessen the likelihood of food allergy reactions. Previous structural and biochemical data have indicated that 2S albumins from tree nuts and peanuts are potent allergens, and that their structures are sensitive to strong reducing agents such as dithiothreitol. This study demonstrates that the generally regarded as safe (GRAS) compound sodium sulfite effectively disrupted the structure of the cashew 2S albumin, Ana o 3, in a temperature-dependent manner. This study also showed that sulfite is effective at disrupting the disulfide bond within the cashew legumin, Ana o 2. Immunoblotting and ELISA demonstrated that the binding of cashew proteins by rabbit IgG or IgE from cashew-allergic patients was markedly lowered following treatment with sodium sulfite and heating. The results indicate that incorporation of sodium sulfite, or other food grade reagents with similar redox potential, may be useful processing methods to lower or eliminate IgE binding to food allergens.
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Affiliation(s)
- Christopher P Mattison
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, Louisiana 70124, United States
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24
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Koid AE, Chapman MD, Hamilton RG, van Ree R, Versteeg SA, Dreskin SC, Koppelman SJ, Wünschmann S. Ara h 6 complements Ara h 2 as an important marker for IgE reactivity to peanut. J Agric Food Chem 2014; 62:206-13. [PMID: 24328145 PMCID: PMC4055559 DOI: 10.1021/jf4022509] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The similarities of two major peanut allergens, Ara h 2 and Ara h 6, in molecular size, amino acid sequence, and structure have made it difficult to obtain natural Ara h 6 free of Ara h 2. The objectives of this study were to purify natural Ara h 6 that is essentially free of Ara h 2 and to compare its IgE reactivity and potency in histamine release assays to Ara h 2. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the highly purified allergen (<0.01% Ara h 2) revealed a single 14.5 kD band, and the identity of Ara h 6 was confirmed by liquid chromatography-tandem mass spectrometry. Ara h 6 showed a higher seroprevalence in chimeric IgE enzyme-linked immunosorbent assay (n = 54) but a weaker biological activity in basophil histamine release assays than Ara h 2. Purified Ara h 6 will be useful for diagnostic IgE antibody assays as well as molecular and cellular studies to investigate the immunological mechanisms of peanut allergy.
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Affiliation(s)
- Audrey E Koid
- INDOOR Biotechnologies, Inc., 1216 Harris St, Charlottesville, VA 22903
| | - Martin D Chapman
- INDOOR Biotechnologies, Inc., 1216 Harris St, Charlottesville, VA 22903
| | - Robert G Hamilton
- Johns Hopkins University School of Medicine, 600 N Wolfe St #6-113, Baltimore, MD 21287
| | - Ronald van Ree
- Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam-Zuidoost, The Netherlands
| | - Serge A Versteeg
- Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam-Zuidoost, The Netherlands
| | - Stephen C Dreskin
- University of Colorado Denver, School of Medicine, 1250 14th St, Denver, CO 80202
| | | | - Sabina Wünschmann
- INDOOR Biotechnologies, Inc., 1216 Harris St, Charlottesville, VA 22903
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25
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Ebisawa M, Brostedt P, Sjölander S, Sato S, Borres MP, Ito K. Gly m 2S albumin is a major allergen with a high diagnostic value in soybean-allergic children. J Allergy Clin Immunol 2013; 132:976-8.e1-5. [PMID: 23763971 DOI: 10.1016/j.jaci.2013.04.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 03/21/2013] [Accepted: 04/12/2013] [Indexed: 10/26/2022]
Affiliation(s)
- Motohiro Ebisawa
- Clinical Research Center for Allergy and Rheumatology, Sagamihara National Hospital, Sagamihara, Japan.
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26
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Kim J, Lee JY, Han Y, Ahn K. Significance of Ara h 2 in clinical reactivity and effect of cooking methods on allergenicity. Ann Allergy Asthma Immunol 2012; 110:34-8. [PMID: 23244656 DOI: 10.1016/j.anai.2012.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 09/19/2012] [Accepted: 10/14/2012] [Indexed: 11/16/2022]
Abstract
BACKGROUND The prevalence and clinical severity of peanut allergy vary between Western countries and Asia. It has been suggested that cooking methods are responsible for this discrepancy. OBJECTIVES To evaluate the specific IgE responses to major peanut allergens in peanut allergic Korean children and to examine the influence of different cooking methods on peanut proteins. METHODS Raw peanut protein extracts were immunolabeled with serum samples from 42 children with a level of peanut specific IgE of 15 kUA/L or higher to detect specific binding to Ara h 1, Ara h 2, and Ara h 3. Clinical severity scores were assessed on a scale of 0 to 5. Protein extracts from boiled, roasted, fried, and pickled peanuts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with pooled serum samples from 7 patients. RESULTS Most patients' serum samples reacted with Ara h 1 (76.2%) and Ara h 3 (78.6%) from raw peanuts, whereas only 53.0% of patients had specific IgE against Ara h 2. IgE binding to Ara h 2 was more prevalent in patients with more severe reaction than in those with mild reactions. IgE binding to Ara h 2 was increased by roasting, but there was significantly less IgE binding after vinegar treatment. CONCLUSION Our results suggest that Ara h 2 is an important allergen to predict clinical symptoms but less prevalent in Korean children than in Western children. This finding may be attributed in part to different cooking methods and dietary habits among regions.
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Affiliation(s)
- Jihyun Kim
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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27
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Nair DN, Singh V, Yamaguchi Y, Singh DD. Jatropha curcas hemagglutinin is similar to a 2S albumin allergen from the same source and has unique sugar affinities. Planta 2012; 236:1499-1505. [PMID: 22798079 DOI: 10.1007/s00425-012-1702-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Accepted: 06/25/2012] [Indexed: 06/01/2023]
Abstract
We have previously reported the purification and preliminary X-ray characterization of a hemagglutinin from the seeds of Jatropha curcas and, with the detailed sequencing information available now, we find that it is similar to a 2S albumin allergen isolated from the same source. Through a search of Jatropha genome database (http://www.kazusa.or.jp/jatropha/), we map it to the sequence id JcCA0234191 (now referred to as Jcr4S00619.70 in the new version, release 4.5) which has a conserved alpha amylase inhibitor/seed storage protein domain found in the 2S albumin allergens. The putative sequence of the small and large chains of the protein is assigned and the total mass of the two subunits matches with the intact mass 10 kDa determined through MALDI. The protein retains hemagglutination activity between pH 6-9 and up to 60 °C on heat treatment and its hemagglutination activity is inhibited by sialic acid and fetuin. Bioinformatics studies show that the isolated protein sequence clusters in close association with a 2S albumin from Ricinus communis in phylogeny analysis and has a conservation of the characteristic four disulfide linkage pattern. Hemagglutinins and lectins are known to have allergenic effects through their interaction with immunoglobulin E and histamine release and earlier studies have shown that this interaction can be inhibited by lectin-specific sugars. We hope this report bridges the plant allergens and hemagglutinins further for exploring possible mediation of allergenic activity through sialic acid and complex sugar interactions and generates further interest in the area.
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Affiliation(s)
- Divya N Nair
- Department of Bioinformatics and Structural Biology, Indian Institute of Advanced Research, Koba, Gandhinagar, 382007, Gujarat, India
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28
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Lin J, Bruni FM, Fu Z, Maloney J, Bardina L, Boner AL, Gimenez G, Sampson HA. A bioinformatics approach to identify patients with symptomatic peanut allergy using peptide microarray immunoassay. J Allergy Clin Immunol 2012; 129:1321-1328.e5. [PMID: 22444503 DOI: 10.1016/j.jaci.2012.02.012] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 01/09/2012] [Accepted: 02/09/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Peanut allergy is relatively common, typically permanent, and often severe. Double-blind, placebo-controlled food challenge is considered the gold standard for the diagnosis of food allergy-related disorders. However, the complexity and potential of double-blind, placebo-controlled food challenge to cause life-threatening allergic reactions affects its clinical application. A laboratory test that could accurately diagnose symptomatic peanut allergy would greatly facilitate clinical practice. OBJECTIVE We sought to develop an allergy diagnostic method that could correctly predict symptomatic peanut allergy by using peptide microarray immunoassays and bioinformatic methods. METHODS Microarray immunoassays were performed by using the sera from 62 patients (31 with symptomatic peanut allergy and 31 who had outgrown their peanut allergy or were sensitized but were clinically tolerant to peanut). Specific IgE and IgG(4) binding to 419 overlapping peptides (15 mers, 3 offset) covering the amino acid sequences of Ara h 1, Ara h 2, and Ara h 3 were measured by using a peptide microarray immunoassay. Bioinformatic methods were applied for data analysis. RESULTS Individuals with peanut allergy showed significantly greater IgE binding and broader epitope diversity than did peanut-tolerant individuals. No significant difference in IgG(4) binding was found between groups. By using machine learning methods, 4 peptide biomarkers were identified and prediction models that can predict the outcome of double-blind, placebo-controlled food challenges with high accuracy were developed by using a combination of the biomarkers. CONCLUSIONS In this study, we developed a novel diagnostic approach that can predict peanut allergy with high accuracy by combining the results of a peptide microarray immunoassay and bioinformatic methods. Further studies are needed to validate the efficacy of this assay in clinical practice.
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Affiliation(s)
- Jing Lin
- Pediatric Allergy and Immunology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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29
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Glaumann S, Nopp A, Johansson SGO, Rudengren M, Borres MP, Nilsson C. Basophil allergen threshold sensitivity, CD-sens, IgE-sensitization and DBPCFC in peanut-sensitized children. Allergy 2012; 67:242-7. [PMID: 22126416 DOI: 10.1111/j.1398-9995.2011.02754.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Immunoglobulin E (IgE)-sensitization to peanut is common and can indicate an allergy. A positive test needs to be confirmed by a double-blind, placebo-controlled food challenge (DBPCFC), which is regarded as 'the gold standard'. The aim of the study was to evaluate the basophil allergen threshold sensitivity (CD-sens) and antibodies to peanut allergen components in relation to DBPCFC in the diagnoses of peanut allergy in children. METHODS Thirty-eight children with suspected peanut allergy underwent a DBPCFC. CD-sens to peanut and Ara h 2 were analysed as well as IgE-antibody to peanut and some of its allergen components (Ara h 1, 2, 3, 8 and 9). RESULTS Twenty-five children had a positive DBPCFC, and 92% of these were positive in CD-sens to peanut and Ara h 2. Two children with a positive DBPCFC were classified as 'low-responders' and were not further evaluated. Children positive in DBPCFC had higher CD-sens values to peanut (median 1.3; range 0.4-29, n = 21) compared with children negative in DBPCFC (median 0; range 0-0.5, n = 13) (P < 0.0001). A positive DBPCFC correspond with increased levels of IgE-antibody to Ara h 1, 2 and 3 compared with those with a negative challenge (P < 0.0001 for all). All children with a negative CD-sens were negative in DBPCFC. CONCLUSION In this study, a negative CD-sens to peanut excluded peanut allergy. Both tests, CD-sens to peanut and immunoassay for IgE-antibody to the peanut components, appear to be safe, time saving and cost-effective complements to DBPCFC.
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Affiliation(s)
- S Glaumann
- Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Sweden
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30
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Mueller GA, Gosavi RA, Pomés A, Wünschmann S, Moon AF, London RE, Pedersen LC. Ara h 2: crystal structure and IgE binding distinguish two subpopulations of peanut allergic patients by epitope diversity. Allergy 2011; 66:878-85. [PMID: 21255036 DOI: 10.1111/j.1398-9995.2010.02532.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Peanut allergy affects 1% of the population and causes the most fatal food-related anaphylactic reactions. The protein Ara h 2 is the most potent peanut allergen recognized by 80-90% of peanut allergic patients. METHODS The crystal structure of the major peanut allergen Ara h 2 was determined for the first time at 2.7 Å resolution using a customized maltose-binding protein (MBP)-fusion system. IgE antibody binding to the MBP fusion construct vs the natural allergen was compared by ELISA using sera from peanut allergic patients. RESULTS The structure of Ara h 2 is a five-helix bundle held together by four disulfide bonds and related to the prolamin protein superfamily. The fold is most similar to other amylase and trypsin inhibitors. The MBP--Ara h 2 fusion construct was positively recognized by IgE from 76% of allergic patients (25/33). Two populations of patients could be identified. Subpopulation 1 (n = 14) showed an excellent correlation of IgE antibody binding to natural vs recombinant Ara h 2. Subpopulation 2 (n = 15) showed significantly reduced IgE binding to the MBP fusion protein. Interestingly, about 20% of the IgE binding in subpopulation 2 could be recovered by increasing the distance between MBP and Ara h 2 in a second construct. DISCUSSION The reduced IgE binding to the MBP--Ara h 2 of subpopulation 2 indicates that the MBP molecule protects an immunodominant epitope region near the first helix of Ara h 2. Residues involved in the epitope(s) are suggested by the crystal structure. The MBP--Ara h 2 fusion constructs will be useful to further elucidate the relevance of certain epitopes to peanut allergy.
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MESH Headings
- 2S Albumins, Plant/chemistry
- 2S Albumins, Plant/genetics
- 2S Albumins, Plant/immunology
- 2S Albumins, Plant/metabolism
- Antigens, Plant/chemistry
- Antigens, Plant/genetics
- Antigens, Plant/immunology
- Antigens, Plant/metabolism
- Arachis/genetics
- Arachis/immunology
- Arachis/metabolism
- Crystallization
- Crystallography, X-Ray
- Glycoproteins/chemistry
- Glycoproteins/genetics
- Glycoproteins/immunology
- Glycoproteins/metabolism
- Humans
- Immunodominant Epitopes/chemistry
- Immunodominant Epitopes/genetics
- Immunodominant Epitopes/immunology
- Immunoglobulin E/immunology
- Immunoglobulin E/metabolism
- Maltose-Binding Proteins/chemistry
- Maltose-Binding Proteins/genetics
- Maltose-Binding Proteins/metabolism
- Models, Molecular
- Peanut Hypersensitivity/classification
- Peanut Hypersensitivity/diagnosis
- Peanut Hypersensitivity/immunology
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
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Affiliation(s)
- G A Mueller
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
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31
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Kim JS, Nowak-Węgrzyn A. Component-resolved diagnostics: shedding light on the so-called 'squishy science' of food allergies? Int Arch Allergy Immunol 2011; 156:231-3. [PMID: 21720168 DOI: 10.1159/000324834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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32
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Hu CQ, Chen HB, Gao JY, Luo CP, Ma XJ, Tong P. High-pressure microfluidisation-induced changes in the antigenicity and conformation of allergen Ara h 2 purified from Chinese peanut. J Sci Food Agric 2011; 91:1304-1309. [PMID: 21384372 DOI: 10.1002/jsfa.4318] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 12/16/2010] [Accepted: 12/16/2010] [Indexed: 05/30/2023]
Abstract
BACKGROUND Peanut allergy is one of the most serious food allergies, and Ara h 2 is one of the most important peanut allergens as it is recognised by serum immunoglobulin E from more than 90% of peanut-allergic individuals. Dynamic high-pressure microfluidisation has been widely used in food processing as a new technology. The aim of this study was to investigate the effect of high-pressure microfluidisation on the antigenicity and structure of Ara h 2. Extracted peanut allergen Ara h 2 was treated under a continuous pressure array of 60, 90, 120, 150 and 180 MPa. Immunoreactivity was measured by indirect enzyme-linked immunosorbent assay with rabbit polyclonal antibodies. Secondary structure was analysed by circular dichroism. Surface hydrophobicity and sulfhydryl groups were assessed via fluorescence and UV absorption spectra respectively. RESULTS High-pressure microfluidisation treatment decreased the antigenicity of peanut allergen Ara h 2, changed its secondary structure and increased its UV absorption intensity and surface hydrophobicity. CONCLUSION The change in conformation contributed to the decrease in antigenicity of Ara h 2, and the spatial conformation of peanut allergen Ara h 2 plays a critical role in its antigenicity.
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Affiliation(s)
- Chun-qiu Hu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
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33
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Jiang S, Zhou Z, Sun Y, Wang S. [Progress of researches on the allergens Ara h 1, Ara h 2 and Ara h 3 from peanut]. Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 2010; 27:1401-1405. [PMID: 21375004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Peanut is one of the most popular foods in the world due to its high nutrition; however, it contains multiple seed storage proteins which are identified as allergens and hence are the most common cause of life-threatening, IgE-mediated anaphylaxis among the hypersensitive individuals. Three peanut proteins, Arachis hypogaea allergy 1, 2, 3 (Ara h 1, Ara h 2 and Ara h 3), which have the common biochemical characteristics like resistance to proteases and heat, are considered as the major allergens because they are recognized by serum IgE from a peanut-allergic patient population. The linear IgE-binding epitopes in the allergens lay the foundation of the anaphylaxis in the peanut-allergic individuals. Peanut allergy is often a life-long problem, so many investigators are focusing on decreasing clinical reactivity. In this review, the latest advances in the researches on biochemical characteristics, structure and function of the three major allergens were described and particular attention was given to the immunity properties of the three allergens. The future research directions were also discussed.
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Affiliation(s)
- Shengjuan Jiang
- College of Life Science, Anhui Science and Technology University, Fengyang 233100, China.
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Asarnoj A, Movérare R, Ostblom E, Poorafshar M, Lilja G, Hedlin G, van Hage M, Ahlstedt S, Wickman M. IgE to peanut allergen components: relation to peanut symptoms and pollen sensitization in 8-year-olds. Allergy 2010; 65:1189-95. [PMID: 20146729 DOI: 10.1111/j.1398-9995.2010.02334.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Allergen-specific IgE testing is often performed with crude peanut extract, but the results may be difficult to interpret because of cross-reactions between peanut and other plant allergens. The aim was to investigate IgE reactivity to peanut allergen components in children from a birch-rich region in relation to pollen sensitization and peanut symptoms. METHODS From a birth cohort, clinical parameters were obtained through questionnaires and IgE antibody levels to peanut and birch pollen were measured. Different peanut/birch sensitization phenotypes were defined among 200 selected children. IgE reactivity to peanut and pollen allergen components was analysed using microarray technique. RESULTS Peanut symptoms were reported in 87% of the children with IgE reactivity to any of the peanut allergens Ara h 1, 2 or 3 but not to Ara h 8 (n = 46) vs 17% of children with IgE reactivity to Ara h 8 but not to Ara h 1, 2 or 3 (n = 23), P < 0.001. Furthermore, symptoms were more severe in children with Ara h 1, 2 or 3 reactivity. Children with IgE reactivity both to Ara h 2 and to Ara h 1 or 3 more often reported peanut symptoms than children with IgE only to Ara h 2 (97%vs 70%, P = 0.016), particularly respiratory symptoms (50%vs 9%, P = 0.002). CONCLUSIONS IgE analysis to peanut allergen components may be used to distinguish between peanut-sensitized individuals at risk of severe symptoms and those likely to have milder or no symptoms to peanut if sensitized to pollen allergens and their peanut homologue allergens.
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MESH Headings
- 2S Albumins, Plant/immunology
- Antigens, Plant/immunology
- Arachis/immunology
- Betula/immunology
- Child
- Cohort Studies
- Cross Reactions
- Female
- Glycoproteins/immunology
- Humans
- Immunoglobulin E/blood
- Male
- Peanut Hypersensitivity/complications
- Peanut Hypersensitivity/epidemiology
- Peanut Hypersensitivity/etiology
- Peanut Hypersensitivity/immunology
- Peanut Hypersensitivity/physiopathology
- Pollen/immunology
- Rhinitis, Allergic, Seasonal/complications
- Rhinitis, Allergic, Seasonal/epidemiology
- Rhinitis, Allergic, Seasonal/immunology
- Rhinitis, Allergic, Seasonal/physiopathology
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Affiliation(s)
- A Asarnoj
- National Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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Hu CQ, Gao JY, Chen HB, Luo CP, Yan F. [Effect of heat treatment on the antigenicity and conformation of peanut allergen Ara h 2]. Guang Pu Xue Yu Guang Pu Fen Xi 2010; 30:2550-2554. [PMID: 21105438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Peanut allergen Ara h 2 was extracted from peanuts and was identified by SDS-PAGE and MALDI-TOF-MS. Effect of heat treatment on the antigenicity and structure of Ara h 2 was measured by indirect ELISA, CD, fluorescence and UV absorption spectra. The results showed that the antigenicity of Ara h 2 had a slight increase after being heated at 55 or 70 degrees C, while above 85 degrees C the antigenicity decreased significantly, and the antigeicity of Ara h 2 decreased with increasing temperature. The CD showed that the secondary structure of Ara h 2 was changed after heat treatment. The ANS fluorescence probe emission spectra analysis demonstrated that the heat treatment induced an increase in surface hydrophobicity of Ara h 2. The UV absorption spectra showed that the absorption maximum wavelength was increased when Ara h 2 was heated except the sample heating at 50 degrees C for 30 min. So the changes in conformation of Ara h 2 lead to the antigenicity degression.
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Affiliation(s)
- Chun-qiu Hu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
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Schmitt DA, Nesbit JB, Hurlburt BK, Cheng H, Maleki SJ. Processing can alter the properties of peanut extract preparations. J Agric Food Chem 2010; 58:1138-1143. [PMID: 20028112 DOI: 10.1021/jf902694j] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
As peanut allergy is an increasing public health risk, affecting over 1% of the United States and United Kingdom school children, it is important that methods and reagents for accurate diagnosis of food allergy and detection of allergenic foods are reliable and consistent. Given that most current experimental, diagnostic, and detection tests rely on the presence of soluble allergens in food extracts, we investigated the effects of thermal processing on the solubility and IgE binding of the major peanut allergens, Ara h 1 and Ara h 2. The soluble and insoluble fractions of peanuts that were boiled, fried, and roasted were subjected to electrophoresis and Western blot analysis using anti-Ara h 1 and anti-Ara h 2 antibodies and serum IgE from peanut allergic individuals. Overall protein solubility is reduced with processing and IgE binding increases in the insoluble fractions, due mostly to the increase in the amount of insoluble proteins, with increased time of heating in all processes tested. Therefore, it can be concluded that thermal processing of peanuts alters solubility, and the differences in protein solubility within various extract preparations may contribute to inconsistent skin prick test and immunoassay results, particularly when nonstandardized reagents are used.
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Affiliation(s)
- David A Schmitt
- US Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, 1100 Robert E Lee Boulevard, New Orleans, Louisiana 70124, USA
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Ramos ML, Huntley JJ, Maleki SJ, Ozias-Akins P. Identification and characterization of a hypoallergenic ortholog of Ara h 2.01. Plant Mol Biol 2009; 69:325-335. [PMID: 19009240 DOI: 10.1007/s11103-008-9428-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 10/29/2008] [Indexed: 05/27/2023]
Abstract
Peanut (Arachis hypogaea L.), can elicit type I allergy becoming the most common cause of fatal food-induced anaphylactic reactions. Strict avoidance is the only effective means of dealing with this allergy. Ara h 2, a peanut seed storage protein, has been identified as the most potent peanut allergen and is recognized by approximately 90% of peanut hypersensitive individuals in the US. Because peanut has limited genetic variation, wild relatives are a good source of genetic diversity. After screening 30 Arachis duranensis accessions by EcoTILLing, we characterized five different missense mutations in ara d 2.01. None of these polymorphisms induced major conformational modifications. Nevertheless, a polymorphism in the immunodominant epitope #7 (S73T) showed a 56-99% reduction in IgE-binding activity and did not affect T cell epitopes, which must be retained for effective immunotherapy. The identification of natural hypoallergenic isoforms positively contributes to future immunological and therapeutic studies and peanut cultivar development.
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Affiliation(s)
- M Laura Ramos
- Department of Horticulture, University of Georgia, Tifton Campus, Tifton, GA 31793, USA
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39
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Dooper MMBW, Plassen C, Holden L, Lindvik H, Faeste CK. Immunoglobulin E cross-reactivity between lupine conglutins and peanut allergens in serum of lupine-allergic individuals. J Investig Allergol Clin Immunol 2009; 19:283-291. [PMID: 19639724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Lupine is used increasingly in food products. The development of lupine allergy in peanut-allergic patients is believed to occur as a result of cross-reactivity between lupine and peanut proteins. OBJECTIVE To investigate the degree of immunoglobulin (Ig) E cross-reactivity between allergens in lupine and peanut. METHODS We investigated IgE cross-reactivity between lupine alpha-, beta-, gamma-, and delta-conglutins and the major peanut allergens Ara h 1, Ara h 2 and Ara h 3 using enzyme-linked immunosorbent assay with sera from patients with coexisting peanut and lupine allergy. RESULTS Peanut proteins inhibited IgE binding towards alpha- conglutins, delta-conglutins, and, to a lesser degree, beta-conglutins, while no IgE cross-reaction with delta-conglutin was observed. Ara h 2 most potently inhibited IgE binding to lupine and delta-conglutins, while Ara h 1 most potently cross-reacted with beta-conglutin. Ara h 3 was apparently not involved in these mechanisms. CONCLUSIONS The present study reveals IgE cross-reactivity between the 2S albumins Ara h 2 and delta-conglutin, and the 7S vicilin-like Ara h 1 and beta-conglutin, which are possibly based on homologies between phylogenetically related proteins. Ara h 2 was the most potent inhibitor of IgE binding to lupine conglutins.
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Chu Y, Faustinelli P, Ramos ML, Hajduch M, Stevenson S, Thelen JJ, Maleki SJ, Cheng H, Ozias-Akins P. Reduction of IgE binding and nonpromotion of Aspergillus flavus fungal growth by simultaneously silencing Ara h 2 and Ara h 6 in peanut. J Agric Food Chem 2008; 56:11225-11233. [PMID: 19007236 DOI: 10.1021/jf802600r] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The most potent peanut allergens, Ara h 2 and Ara h 6, were silenced in transgenic plants by RNA interference. Three independent transgenic lines were recovered after microprojectile bombardment, of which two contained single, integrated copies of the transgene. The third line contained multiple copies of the transgene. Ara h 2 expression was significantly suppressed in all three lines, whereas Ara h 6 was reduced in two lines. Expression of peanut allergens Ara h 1 and Ara h 3 was not noticeably affected. Significant reduction of human IgE binding to Ara h 2 and Ara h 6 also was observed. Seed weight and germination data from transgenic and nontransgenic segregants showed no significant differences. Data collected from in vitro Aspergillus flavus infection indicate no significant difference in fungal growth between the transgenic lines and the nontransgenic controls. These data suggest that silencing Ara h 2 and Ara h 6 is a feasible approach to produce hypoallergenic peanut.
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Affiliation(s)
- Ye Chu
- Department of Horticulture, University of Georgia, 31793, USA
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