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Tuppo L, Alessandri C, Zaccaro L, Giangrieco I, Tamburrini M, Mari A, Ciardiello MA. Isolation, Characterization and IgE Binding of Two 2S Albumins of Pomegranate Seeds. Foods 2024; 13:1965. [PMID: 38998471 PMCID: PMC11241328 DOI: 10.3390/foods13131965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/14/2024] [Accepted: 06/19/2024] [Indexed: 07/14/2024] Open
Abstract
Literature reports suggest that the presence of proteins in pomegranate seeds is responsible for sensitization and IgE-mediated allergic reactions. The objective of this study was the analysis of a pomegranate seed extract and the isolation and characterization of proteins contained in high amounts. The extract characterization showed a protein profile with main bands at about 18 kDa and below 10 kDa upon SDS-PAGE, and molecules were recognized by specific IgEs upon immunoblotting. Then, two new 2S albumins, a monomeric and a heterodimeric one, were isolated by using classical biochemical methods. They were identified via direct protein sequencing and mass spectrometry, and their primary structure was analyzed and compared with homologous allergenic proteins via bioinformatics. In an Italian population of 703 suspected allergic patients, analyzed by using the FABER® test, the frequency of sensitization to the monomeric and heterodimeric 2S albumins was 1.7% and 0.28%, respectively. This study reports for the first time the isolation and characterization of two 2S albumins from pomegranate seeds. The clinical relevance of these molecules needs further investigation, for instance in populations having different exposures and allergy profiles.
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Affiliation(s)
- Lisa Tuppo
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
| | - Claudia Alessandri
- Associated Centers for Molecular Allergology (CAAM), 00100 Rome, Italy; (C.A.); (A.M.)
| | - Laura Zaccaro
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), 80131 Naples, Italy;
| | - Ivana Giangrieco
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
| | - Maurizio Tamburrini
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
| | - Adriano Mari
- Associated Centers for Molecular Allergology (CAAM), 00100 Rome, Italy; (C.A.); (A.M.)
| | - Maria Antonietta Ciardiello
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
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Koppelman SJ, de Jong GAH, Marsh J, Johnson P, Dowell E, Perusko M, Westphal A, van Hage M, Baumert J, Apostolovic D. Novel post-translationally cleaved Ara h 2 proteoforms: Purification, characterization and IgE-binding properties. Int J Biol Macromol 2024; 264:130613. [PMID: 38447836 DOI: 10.1016/j.ijbiomac.2024.130613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/01/2024] [Accepted: 03/02/2024] [Indexed: 03/08/2024]
Abstract
The 2S albumins Ara h 2 and Ara h 6 have been shown to be the most important source of allergenicity in peanut. Several isoforms of these allergens have been described. Using extraction and liquid chromatography we isolated proteins with homology to Ara h 2 and characterized hitherto unknown Ara h 2 proteoforms with additional post-translational cleavage. High-resolution mass spectrometry located the cleavage site on the non-structured loop of Ara h 2 while far UV CD spectroscopy showed a comparable structure to Ara h 2. The cleaved forms of Ara h 2 were present in genotypes of peanut commonly consumed. Importantly, we revealed that newly identified Ara h 2 cleaved proteoforms showed comparable IgE-binding using sera from 28 peanut-sensitized individuals, possessed almost the same IgE binding potency and are likely similarly allergenic as intact Ara h 2. This makes these newly identified forms relevant proteoforms of peanut allergen Ara h 2.
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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
| | | | - Justin Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Emily Dowell
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Marija Perusko
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Adrie Westphal
- Wageningen University and Research (WUR), Wageningen, the Netherlands
| | - Marianne van Hage
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Joseph Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Danijela Apostolovic
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
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Marini-Rapoport O, Fernández-Quintero ML, Keswani T, Zong G, Shim J, Pedersen LC, Mueller GA, Patil SU. Defining the cross-reactivity between peanut allergens Ara h 2 and Ara h 6 using monoclonal antibodies. Clin Exp Immunol 2024; 216:25-35. [PMID: 38346116 PMCID: PMC10929694 DOI: 10.1093/cei/uxae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/08/2023] [Accepted: 02/09/2024] [Indexed: 03/13/2024] Open
Abstract
In peanut allergy, Arachis hypogaea 2 (Ara h 2) and Arachis hypogaea 6 (Ara h 6) are two clinically relevant peanut allergens with known structural and sequence homology and demonstrated cross-reactivity. We have previously utilized X-ray crystallography and epitope binning to define the epitopes on Ara h 2. We aimed to quantitatively characterize the cross-reactivity between Ara h 2 and Ara h 6 on a molecular level using human monoclonal antibodies (mAbs) and structural characterization of allergenic epitopes. We utilized mAbs cloned from Ara h 2 positive single B cells isolated from peanut-allergic, oral immunotherapy-treated patients to quantitatively analyze cross-reactivity between recombinant Ara h 2 (rAra h 2) and Ara h 6 (rAra h 6) proteins using biolayer interferometry and indirect inhibitory ELISA. Molecular dynamics simulations assessed time-dependent motions and interactions in the antibody-antigen complexes. Three epitopes-conformational epitopes 1.1 and 3, and the sequential epitope KRELRNL/KRELMNL-are conserved between Ara h 2 and Ara h 6, while two more conformational and three sequential epitopes are not. Overall, mAb affinity was significantly lower to rAra h 6 than it was to rAra h 2. This difference in affinity was primarily due to increased dissociation of the antibodies from rAra h 6, a phenomenon explained by the higher conformational flexibility of the Ara h 6-antibody complexes in comparison to Ara h 2-antibody complexes. Our results further elucidate the cross-reactivity of peanut 2S albumins on a molecular level and support the clinical immunodominance of Ara h 2.
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Affiliation(s)
- Orlee Marini-Rapoport
- Harvard University, Cambridge, MA, USA
- Food Allergy Center, Massachusetts General Hospital, Boston, MA, USA
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, USA
| | | | - Tarun Keswani
- Food Allergy Center, Massachusetts General Hospital, Boston, MA, USA
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Guangning Zong
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Jane Shim
- Food Allergy Center, Massachusetts General Hospital, Boston, MA, USA
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Lars C Pedersen
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Geoffrey A Mueller
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Sarita U Patil
- Food Allergy Center, Massachusetts General Hospital, Boston, MA, USA
- Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, USA
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4
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Warmenhoven HJM, Hulsbos L, Dreskin SC, Akkerdaas JH, Versteeg SA, van Ree R. IgE cross-inhibition between Ara h 1 and Ara h 2 is explained by complex formation of both major peanut allergens. J Allergy Clin Immunol 2023; 152:436-444.e6. [PMID: 37028524 PMCID: PMC10528450 DOI: 10.1016/j.jaci.2023.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 03/10/2023] [Accepted: 03/31/2023] [Indexed: 04/09/2023]
Abstract
BACKGROUND Surprisingly, IgE cross-reactivity between the major peanut allergens Ara h 1, 2, and 3 has been reported despite very low sequence identities. OBJECTIVE We investigated the unexpected cross-reactivity between peanut major allergens. METHODS Cross-contamination of purified natural Ara h 1, 2, 3, and 6 was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blot test, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and sandwich enzyme-linked immunosorbent assay (ELISA). IgE cross-reactivity was studied with sera of peanut-allergic patients (n = 43) by ELISA and ImmunoCAP inhibition using both intact natural and recombinant allergens and synthetic peptides representing postulated Ara h 1 and Ara h 2 cross-reactive epitopes. RESULTS Both purified nAra h 1 and nAra h 3 were demonstrated to contain small but significant amounts of Ara h 2 and Ara h 6 (<1%) by sandwich ELISA, SDS-PAGE/Western blot analysis, and LC-MS/MS. IgE cross-inhibition between both 2S albumins and Ara h 1 and Ara h 3 was only observed when using natural purified allergens, not recombinant allergens or synthetic peptides. Apparent cross-reactivity was lost when purified nAra h 1 was pretreated under reducing conditions, suggesting that Ara h 2 and Ara h 6 contaminations may be covalently bound to Ara h 1 via disulfide interactions. CONCLUSION True cross-reactivity of both peanut 2S albumins with Ara h 1 and Ara h 3 could not be demonstrated. Instead, cross-contamination with small quantities was shown to be sufficient to cause significant cross-inhibition that can be misinterpreted as molecular cross-reactivity. Diagnostic tests using purified nAra h 1 and nAra h 3 can overestimate their importance as major allergens as a result of the presence of contaminating 2S albumins, making recombinant Ara h 1 and Ara h 3 a preferred alternative.
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Affiliation(s)
- Hans J M Warmenhoven
- HAL Allergy, J. H. Oortweg, Leiden, The Netherlands; Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Luuk Hulsbos
- HAL Allergy, J. H. Oortweg, Leiden, The Netherlands
| | - Stephen C Dreskin
- Department of Medicine, Division of Allergy and Clinical Immunology, University of Colorado-Denver, Aurora, Colo
| | - Jaap H Akkerdaas
- Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Serge A Versteeg
- Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Ronald van Ree
- Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands; Department of Otorhinolaryngology, Amsterdam University Medical Centers, Amsterdam, The Netherlands.
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5
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Yang X, Bai H, Yin L, Wang J, Xue W, Jia X. Evaluation of allergenic protein profiles in three Chinese high-oleic acid peanut cultivars using NanoLC-Orbitrap mass spectrometry. FOOD SCIENCE AND HUMAN WELLNESS 2023. [DOI: 10.1016/j.fshw.2022.09.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kanchan K, Shankar G, Huffaker MF, Bahnson HT, Chinthrajah RS, Sanda S, Manohar M, Ling H, Paschall JE, Toit GD, Ruczinski I, Togias A, Lack G, Nadeau KC, Jones SM, Nepom GT, Mathias RA. HLA-associated outcomes in peanut oral immunotherapy trials identify mechanistic and clinical determinants of therapeutic success. Front Immunol 2022; 13:941839. [PMID: 36466872 PMCID: PMC9717393 DOI: 10.3389/fimmu.2022.941839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/06/2022] [Indexed: 11/19/2022] Open
Abstract
Rationale Previous studies identified an interaction between HLA and oral peanut exposure. HLA-DQA1*01:02 had a protective role with the induction of Ara h 2 epitope-specific IgG4 associated with peanut consumption during the LEAP clinical trial for prevention of peanut allergy, while it was a risk allele for peanut allergy in the peanut avoidance group. We have now evaluated this gene-environment interaction in two subsequent peanut oral immunotherapy (OIT) trials - IMPACT and POISED - to better understand the potential for the HLA-DQA1*01:02 allele as an indicator of higher likelihood of desensitization, sustained unresponsiveness, and peanut allergy remission. Methods We determined HLA-DQA1*01:02 carrier status using genome sequencing from POISED (N=118, age: 7-55yr) and IMPACT (N=126, age: 12-<48mo). We tested for association with remission, sustained unresponsiveness (SU), and desensitization in the OIT groups, as well as peanut component specific IgG4 (psIgG4) using generalized linear models and adjusting for relevant covariates and ancestry. Results While not quite statistically significant, a higher proportion of HLA-DQA1*01:02 carriers receiving OIT in IMPACT were desensitized (93%) compared to non-carriers (78%); odds ratio (OR)=5.74 (p=0.06). In this sample we also observed that a higher proportion of carriers achieved remission (35%) compared to non-carriers (22%); OR=1.26 (p=0.80). In POISED, carriers more frequently attained continued desensitization (80% versus 61% among non-carriers; OR=1.28, p=0.86) and achieved SU (52% versus 31%; OR=2.32, p=0.19). psIgG4 associations with HLA-DQA1*01:02 in the OIT arm of IMPACT which included younger study subjects recapitulated patterns noted in LEAP, but no associations of note were observed in the older POISED study subjects. Conclusions Findings across three clinical trials show a pattern of a gene environment interaction between HLA and oral peanut exposure. Age, and prior sensitization contribute additional determinants of outcomes, consistent with a mechanism of restricted antigen recognition fundamental to driving protective immune responses to OIT.
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Affiliation(s)
- Kanika Kanchan
- Division of Allergy and Clinical Immunology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Gautam Shankar
- Division of Allergy and Clinical Immunology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | | | - Henry T. Bahnson
- The Immune Tolerance Network, Seattle, WA, United States,Benaroya Research Institute at Virginia Mason, Seattle, WA, United States
| | - R Sharon Chinthrajah
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University, Palo Alto, CA, United States
| | - Srinath Sanda
- The Immune Tolerance Network, San Francisco, CA, United States
| | - Monali Manohar
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University, Palo Alto, CA, United States
| | - Hua Ling
- Institute of Genetic Medicine, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Justin E. Paschall
- Institute of Genetic Medicine, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - 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’ National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Ingo Ruczinski
- Department of Biostatistics, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Alkis Togias
- Division of Allergy, Immunology, and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Gideon Lack
- The Department of Pediatric Allergy, Division of Asthma, Allergy and Lung Biology, King’s College London, and Guy’s and St Thomas’ National Health Service (NHS) Foundation Trust, London, United Kingdom
| | - Kari C. Nadeau
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University, Palo Alto, CA, United States
| | - Stacie M. Jones
- Department of Pediatrics, University of Arkansas for Medical Sciences and Arkansas Children’s Hospital, Little Rock, AR, United States
| | - Gerald T. Nepom
- The Immune Tolerance Network, Seattle, WA, United States,Benaroya Research Institute at Virginia Mason, Seattle, WA, United States
| | - Rasika A. Mathias
- Division of Allergy and Clinical Immunology, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, United States,*Correspondence: Rasika Mathias,
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7
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Faisal S, Zhang J, Meng S, Shi A, Li L, Wang Q, Maleki SJ, Adhikari B. Effect of high-moisture extrusion and addition of transglutaminase on major peanut allergens content extracted by three step sequential method. Food Chem 2022; 385:132569. [PMID: 35338998 DOI: 10.1016/j.foodchem.2022.132569] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 01/30/2022] [Accepted: 02/24/2022] [Indexed: 02/04/2023]
Abstract
The effect of high-moisture extrusion (HME) with or without transglutaminase (TGase) on peanut allergen levels and their extractability was studied. A three-stage sequential protein extraction significantly improved the protein recovery in processed samples (extrudate meat analogue); from 5.56 to 18.75 mg/100 mg without TGase, and from 4.59 to 20.82 mg/100 mg with 0.3% TGase. The total major allergen content was reduced by 91% (Ara h 1), 61% (Ara h 2), 60% (Ara h 6), and 55% (Ara h 3). Western-blot analysis of soluble extracts reflected the presence of Ara h 1 and Ara h 2 in significantly lower, indicating a potential reduction in IgE binding. During different processing zones, the most significant reduction in allergenic proteins was in the melting zone. The significant alteration in secondary and tertiary structures as a result of crosslinking shearing and degradation of proteins is likely to lead to allergen reduction.
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Affiliation(s)
- Shah Faisal
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Research Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, PR China
| | - Jinchuang Zhang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Research Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, PR China
| | - Shi Meng
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Research Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, PR China; Nestle R&D, Building 5, Courtyard 6, Jiuxianqiao Rd, Chaoyang district, Beijing 100015, PR China
| | - Aimin Shi
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Research Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, PR China; Collaborative Innovation Center for Modern Grain Circulation and Safety, College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, PR China
| | - Liu Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Research Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, PR China
| | - Qiang Wang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Research Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing 100193, PR China; Collaborative Innovation Center for Modern Grain Circulation and Safety, College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, PR China.
| | - Soheila J Maleki
- United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, 1100 Robert E. Lee Blvd., New Orleans, LA 70124, USA, USA
| | - Benu Adhikari
- School of Science, RMIT University, Melbourne, VIC 3083, Australia
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Hazebrouck S, Canon N, Dreskin SC. The Effector Function of Allergens. FRONTIERS IN ALLERGY 2022; 3:818732. [PMID: 35386644 PMCID: PMC8974742 DOI: 10.3389/falgy.2022.818732] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/14/2022] [Indexed: 01/29/2023] Open
Abstract
Allergens are antigens that generate an IgE response (sensitization) in susceptible individuals. The allergenicity of an allergen can be thought of in terms of its ability to sensitize as well as its ability to cross-link IgE/IgE receptor complexes on mast cells and basophils leading to release of preformed and newly formed mediators (effector activity). The identity of the allergens responsible for sensitization may be different from those that elicit an allergic response. Effector activity is determined by (1) the amount of specific IgE (sIgE) and in some circumstances the ratio of sIgE to total IgE, (2) the number of high affinity receptors for IgE (FcεR1) on the cell surface, (3) the affinity of binding of sIgE for its epitope and, in a polyclonal response, the collective avidity, (4) the number and spatial relationships of IgE binding epitopes on the allergen and (5) the presence of IgG that can bind to allergen and either block binding of sIgE and/or activate low affinity IgG receptors that activate intracellular inhibitory pathways. This review will discuss these important immunologic and physical properties that contribute to the effector activity of allergens.
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Affiliation(s)
- Stéphane Hazebrouck
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
| | - Nicole Canon
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO, United States
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO, United States
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Ehlers AM, Hartog Jager CF, Knulst AC, Otten HG. Distinction between peanut allergy and tolerance by characterization of B cell receptor repertoires. Allergy 2021; 76:2753-2764. [PMID: 33969502 PMCID: PMC8453529 DOI: 10.1111/all.14897] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 04/08/2021] [Accepted: 04/25/2021] [Indexed: 12/11/2022]
Abstract
Background Specific IgE against a peanut 2S albumin (Ara h 2 or 6) is the best predictor of clinically relevant peanut sensitization. However, sIgE levels of peanut allergic and those of peanut sensitized but tolerant patients partly overlap, highlighting the need for improved diagnostics to prevent incorrect diagnosis and consequently unnecessary food restrictions. Thus, we sought to explore differences in V(D)J gene transcripts coding for peanut 2S albumin‐specific monoclonal antibodies (mAbs) from allergic and sensitized but tolerant donors. Methods 2S albumin‐binding B‐cells were single‐cell sorted from peripheral blood of peanut allergic (n=6) and tolerant (n=6) donors sensitized to Ara h2 and/or 6 (≥ 0.1 kU/l) and non‐atopic controls (n=5). h 2 and/or 6 (≥ 0.1 kU/l). Corresponding h heavy and light chain gene transcripts were heterologously expressed as mAbs and tested for specificity to native Ara h2 and 6. HCDR3 sequence motifs were identified by Levenshtein distances and hierarchically clustering. Results The frequency of 2S albumin‐binding B cells was increased in allergic (median: 0.01%) compared to tolerant (median: 0.006%) and non‐atopic donors (median: 0.0015%, p = 0.008). The majority of mAbs (74%, 29/39) bound specifically to Ara h 2 and/or 6. Non‐specific mAbs (9/10) were mainly derived from non‐atopic controls. In allergic donors, 89% of heavy chain gene transcripts consisted of VH3 family genes, compared with only 54% in sensitized but tolerant and 63% of non‐atopic donors. Additionally, certain HCDR3 sequence motifs were associated with allergy (n = 4) or tolerance (n = 3) upon hierarchical clustering of their Levenshtein distances. Conclusions Peanut allergy is associated with dominant VH3 family gene usage and certain public antibody sequences (HCDR3 motifs).
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Affiliation(s)
- Anna M. Ehlers
- Center for Translational Immunology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
- Department of Dermatology/Allergology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
| | - Constance F. Hartog Jager
- Center for Translational Immunology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
- Department of Dermatology/Allergology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
| | - André C. Knulst
- Center for Translational Immunology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
- Department of Dermatology/Allergology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
| | - Henny G. Otten
- Center for Translational Immunology University Medical Center Utrecht, Utrecht University Utrecht The Netherlands
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10
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Apostolovic D, Marsh JT, Baumert J, Taylor SL, Westphal A, de Jongh H, Johnson P, de Jong GAH, Koppelman SJ. Purification and Initial Characterization of Ara h 7, a Peanut Allergen from the 2S Albumin Protein Family. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6318-6329. [PMID: 34037388 DOI: 10.1021/acs.jafc.1c00618] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
2S albumins are important peanut allergens. Within this protein family, Ara h 2 and Ara h 6 have been described in detail, but Ara h 7 has received little attention. We now describe the first purification of Ara h 7 and its characterization. Two Ara h 7 isoforms were purified from peanuts. Mass spectrometry revealed that both the isoforms have a post-translation cleavage, a hydroxyproline modification near the N-terminus, and four disulfide bonds. The secondary structure of both Ara h 7 isoforms is highly comparable to those of Ara h 2 and Ara h 6. Both Ara h 7 isoforms bind IgE, and Ara h 7 is capable of inhibiting the binding between Ara h 2 and IgE, suggesting at least partially cross-reactive IgE epitopes. Ara h 7 was found in all main market types of peanut, at comparable levels. This suggests that Ara h 7 is a relevant allergen from the peanut 2S albumin protein family.
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Affiliation(s)
- Danijela Apostolovic
- Immunology and Allergy Division, Department of Medicine Solna, Karolinska Institutet, Solnavägen 1, 171 77 Solna, Sweden
| | - Justin T 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
| | - Joe Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Adrie Westphal
- Biochemistry Dept., Wageningen University and Research, PO Box 17, 6700 AA Wageningen, The Netherlands
| | - Harmen de Jongh
- ProtinConsult, Rozenstraat 19, 3702 VL Zeist, The Netherlands
| | - 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
| | - Govardus A H de Jong
- Wageningen University and Research, Food and Biobased Research. PO Box 17, 6700 AA Wageningen, The Netherlands
| | - 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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11
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Villemet L, Cuchet A, Desvignes C, Sänger-van de Griend CE. Protein mapping of peanut extract with capillary electrophoresis. Electrophoresis 2021; 43:1027-1034. [PMID: 33970506 DOI: 10.1002/elps.202100004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/29/2021] [Accepted: 04/29/2021] [Indexed: 11/07/2022]
Abstract
Protein separation can be achieved with different modes of capillary electrophoresis, such as with capillary gel electroporesis (CGE) or with capillary zone electrophoresis (CZE). CZE protein mapping of peanut extract was approached in four different ways, combining neutral-coated or multilayer-coated capillaries with pHs well over or under the isoelectric point range of the proteins of interest. At acidic pHs, the mobility ranges of the major peanut allergens Ara h1, Ara h2, Ara h3, and Ara h6 were identified. Although the pH is a major factor in CZE separation, buffers with different compositions but with the same pH and ionic strength showed significantly different resolutions. Different components of the electrolyte were studied in a multifactorial design of experiment. CE-SDS and CZE proved to be suitable for protein mapping and we were able to distinguish different batches of peanut extract and burned peanut extract.
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Affiliation(s)
| | | | | | - Cari E Sänger-van de Griend
- Kantisto BV, Baarn, The Netherlands.,Faculty of Pharmacy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
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12
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Ehlers AM, den Hartog Jager CF, Kardol-Hoefnagel T, Katsburg MMD, Knulst AC, Otten HG. Comparison of Two Strategies to Generate Antigen-Specific Human Monoclonal Antibodies: Which Method to Choose for Which Purpose? Front Immunol 2021; 12:660037. [PMID: 34017336 PMCID: PMC8130674 DOI: 10.3389/fimmu.2021.660037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/12/2021] [Indexed: 11/13/2022] Open
Abstract
Human monoclonal antibodies (mAbs) are valuable tools to link genetic information with functional features and to provide a platform for conformational epitope mapping. Additionally, combined data on genetic and functional features provide a valuable mosaic for systems immunology approaches. Strategies to generate human mAbs from peripheral blood have been described and used in several studies including single cell sequencing of antigen-binding B cells and the establishment of antigen-specific monoclonal Epstein-Barr Virus (EBV) immortalized lymphoblastoid cell lines (LCLs). However, direct comparisons of these two strategies are scarce. Hence, we sought to set up these two strategies in our laboratory using peanut 2S albumins (allergens) and the autoantigen anti-Rho guanosine diphosphate dissociation inhibitor 2 (RhoGDI2, alternatively 'ARHGDIB') as antigen targets to directly compare these strategies regarding costs, time expenditure, recovery, throughput and complexity. Regarding single cell sequencing, up to 50% of corresponding V(D)J gene transcripts were successfully amplified of which 54% were successfully cloned into expression vectors used for heterologous expression. Seventy-five percent of heterologously expressed mAbs showed specific binding to peanut 2S albumins resulting in an overall recovery of 20.3%, which may be increased to around 29% by ordering gene sequences commercially for antibody cloning. In comparison, the establishment of monoclonal EBV-LCLs showed a lower overall recovery of around 17.6%. Heterologous expression of a mAb carrying the same variable region as its native counterpart showed comparable concentration-dependent binding abilities. By directly comparing those two strategies, single cell sequencing allows a broad examination of antigen-binding mAbs in a moderate-throughput manner, while the establishment of monoclonal EBV-LCLs is a powerful tool to select a small number of highly reactive mAbs restricted to certain B cell subpopulations. Overall, both strategies, initially set-up for peanut 2S albumins, are suitable to obtain human mAbs and they are easily transferrable to other target antigens as shown for ARHGDIB.
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Affiliation(s)
- Anna M Ehlers
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Constance F den Hartog Jager
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Tineke Kardol-Hoefnagel
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Miriam M D Katsburg
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - André C Knulst
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Henny G Otten
- Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
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13
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Abstract
Human milk contains a wide range of immunomodulatory factors, including immunoglobulins, human milk oligosaccharides, cytokines, microbiome, innate factors and food antigens. Maternal diet can influence the content of human milk as it is well-established that dietary antigens can be secreted in human milk after maternal consumption, but whether these dietary antigens promote tolerance or sensitization in the infant is a subject of debate. This review summarizes the current literature on these immunologically active factors in human milk, including the microbiome, innate factors, and maternal diet-derived dietary antigens in the context of development of allergic diseases, with the focus on food allergy.
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14
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Kansen HM, van Erp FC, Knulst AC, Ehlers AM, Lyons SA, Knol EF, Meijer Y, Otten HG, van der Ent CK, Le TM. Accurate Prediction of Peanut Allergy in One-Third of Adults Using a Validated Ara h 2 Cutoff. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2020; 9:1667-1674.e3. [PMID: 33248282 DOI: 10.1016/j.jaip.2020.11.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 11/02/2020] [Accepted: 11/09/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND The diagnostic value of peanut components is extensively studied in children, but to a lesser extent in adults with suspected peanut allergy. The use of peanut components in daily practice may reduce the need for double-blind placebo-controlled food challenges (DBPCFCs); however, validation studies are currently lacking. OBJECTIVE To evaluate the diagnostic value of (combined) peanut components and validate a previously found Ara h 2 cutoff level with 100% positive predictive value (PPV) in adults with suspected peanut allergy. METHODS Adults who underwent a peanut DBPCFC were included: 84 patients from a previous study (2002-2012) and 70 new patients (2012-2019). Specific IgE (sIgE) to peanut extract, Ara h 1, 2, 3, 6, and 8 was measured using ImmunoCAP. Diagnostic value was assessed with an area under the curve (AUC) analysis. RESULTS In total, 95 (62%) patients were peanut allergic. sIgE to Ara h 2 and Ara h 6 were the best predictors with an AUC (95% confidence interval) of 0.85 (0.79-0.91) and 0.85 (0.79-0.92), respectively. The Ara h 2 cutoff level with 100% PPV (≥1.75 kUA/L) was validated in the 70 new patients. Thirty percent of all included patients could be classified correctly as peanut allergic using this validated cutoff level. CONCLUSION sIgE to Ara h 2 and Ara h 6 have equally high discriminative ability. Peanut allergy can be predicted accurately in one-third of adults using a validated cutoff level of sIgE to Ara h 2.
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Affiliation(s)
- Hannah M Kansen
- Department of Dermatology and Allergology, University Medical Center, Utrecht University, Utrecht, the Netherlands; Department of Pediatric Pulmonology and Allergology, Wilhelmina Children's Hospital, University Medical Center, Utrecht University, Utrecht, the Netherlands.
| | - Francine C van Erp
- Department of Dermatology and Allergology, University Medical Center, Utrecht University, Utrecht, the Netherlands
| | - André C Knulst
- Department of Dermatology and Allergology, University Medical Center, Utrecht University, Utrecht, the Netherlands; Center of Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Anna M Ehlers
- Department of Dermatology and Allergology, University Medical Center, Utrecht University, Utrecht, the Netherlands; Center of Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Sarah A Lyons
- Department of Dermatology and Allergology, University Medical Center, Utrecht University, Utrecht, the Netherlands
| | - Edward F Knol
- Department of Dermatology and Allergology, University Medical Center, Utrecht University, Utrecht, the Netherlands; Center of Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Yolanda Meijer
- Department of Pediatric Pulmonology and Allergology, Wilhelmina Children's Hospital, University Medical Center, Utrecht University, Utrecht, the Netherlands
| | - Henny G Otten
- Center of Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Cornelis K van der Ent
- Department of Pediatric Pulmonology and Allergology, Wilhelmina Children's Hospital, University Medical Center, Utrecht University, Utrecht, the Netherlands
| | - Thuy-My Le
- Department of Dermatology and Allergology, University Medical Center, Utrecht University, Utrecht, the Netherlands; Center of Translational Immunology, University Medical Center Utrecht, Utrecht, the Netherlands
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15
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Venkataratnam H, Cahill O, Sarangapani C, Cullen PJ, Barry-Ryan C. Impact of cold plasma processing on major peanut allergens. Sci Rep 2020; 10:17038. [PMID: 33046788 PMCID: PMC7550356 DOI: 10.1038/s41598-020-72636-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 08/31/2020] [Indexed: 11/15/2022] Open
Abstract
Cold plasma is emerging as a novel food processing technology, with demonstrated efficacies for microbial inactivation and residual chemical dissipation of food products. Given the technology's multimodal action it has the potential to reduce allergens in foods, however data on the efficacy and mechanisms of action are sparse. This study investigates the efficacy of cold plasma on major peanut allergens (Ara h 1 and Ara h 2). For this purpose, dry, whole peanut (WP) and defatted peanut flour (DPF) were subjected to an atmospheric air discharge using a pin to plate cold plasma reactor for different treatment durations. With increases in plasma exposure, SDS-PAGE analysis revealed reduced protein solubility of the major peanut allergens. Alterations in allergenicity and structure of Ara h 1 and Ara h 2 were examined using ELISA and circular dichroism (CD) spectroscopy. Competitive ELISA with proteins purified from plasma treated WP or DPF revealed reduced antigenicity for both Ara h 1 and Ara h 2. The highest reduction in antigenicity was 65% for Ara h 1 and 66% Ara h 2 when purified from DPF. Results from CD spectroscopy analysis of purified proteins strongly suggests the reduction in antigenicity is due to modifications in the secondary structure of the allergens induced by plasma reactive species. Cold plasma is effective at reducing peanut protein solubility and causes changes in allergen structure leading to reduced antigenicity.
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Affiliation(s)
- Harshitha Venkataratnam
- School of Food Science and Environmental Health, College of Sciences and Health, Technological University Dublin, Cathal Brugha Street, Dublin 1, Republic of Ireland.
| | - Orla Cahill
- School of Food Science and Environmental Health, College of Sciences and Health, Technological University Dublin, Cathal Brugha Street, Dublin 1, Republic of Ireland
| | - Chaitanya Sarangapani
- School of Food Science and Environmental Health, College of Sciences and Health, Technological University Dublin, Cathal Brugha Street, Dublin 1, Republic of Ireland
| | - P J Cullen
- School of Food Science and Environmental Health, College of Sciences and Health, Technological University Dublin, Cathal Brugha Street, Dublin 1, Republic of Ireland
- Centre for Advanced Food Enginomics, School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, Australia
- Plasmaleap Technologies, Merewether Building, City Road, Sydney, Australia
| | - Catherine Barry-Ryan
- School of Food Science and Environmental Health, College of Sciences and Health, Technological University Dublin, Cathal Brugha Street, Dublin 1, Republic of Ireland
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16
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Hemmings O, Du Toit G, Radulovic S, Lack G, Santos AF. Ara h 2 is the dominant peanut allergen despite similarities with Ara h 6. J Allergy Clin Immunol 2020; 146:621-630.e5. [PMID: 32298698 PMCID: PMC7482438 DOI: 10.1016/j.jaci.2020.03.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/14/2020] [Accepted: 03/11/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Arachis hypogaea 2 (Ara h 2)-specific IgE is to date the best serologic marker to diagnose peanut allergy. Ara h 6 shares approximately 60% sequence identity and multiple epitopes with Ara h 2. OBJECTIVE Our aim was to assess the diagnostic utility and relative importance of Ara h 2 and Ara h 6 in peanut allergy. METHODS A cohort 100 of children was studied. The cohort included chidren who had peanut allergy, children who were sensitized to but tolerant of peanut, and children who were neither sensitized nor allergic to peanut. Levels of specific IgE to peanut and individual allergens were quantified by using ImmunoCAP. ImmunoCAP inhibition experiments and mast cell activation tests in response to both Ara h 2 and Ara h 6 were performed. Statistical analyses were done using SPSS version 14 and Prism version 7 software. RESULTS Ara h 2-specific IgE and Ara h 6-specific IgE showed the greatest diagnostic accuracy for peanut allergy when compared with specific IgE to peanut and other peanut allergens. Most patients with peanut allergy were sensitized to both Ara h 2 and Ara h 6. Ara h 2 reduced Ara h 2-specific IgE binding more than Ara h 6 did (P < .001), whereas Ara h 6-specific IgE binding was inhibited to a similar degree by Ara h 2 and Ara h 6 (P = .432). In the mast cell activation test, Ara h 2 induced significantly greater maximal reactivity (P = .001) and a lower half maximal effective concentration (P = .002) than did Ara h 6 when testing cosensitized individuals. CONCLUSIONS Ara h 2-specific IgE and Ara h 6-specific IgE provide the greatest accuracy to diagnose peanut allergy. Ara h 2 is the dominant conglutin in peanut allergy in the United Kingdom, despite a degree of cross-reactivity with Ara h 6.
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Affiliation(s)
- Oliver Hemmings
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom
| | - George Du Toit
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom
| | - Suzana Radulovic
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom
| | - Gideon Lack
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom
| | - Alexandra F Santos
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom.
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17
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de Jongh HHJ, de Jong GAH, Apostolovic D, Taylor SL, Baumert JL, Koppelman SJ. Effect of heat treatment on the conformational stability of intact and cleaved forms ofthe peanut allergen Ara h 6 in relation to its IgE-binding potency. Food Chem 2020; 326:127027. [PMID: 32438232 DOI: 10.1016/j.foodchem.2020.127027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/16/2020] [Accepted: 05/08/2020] [Indexed: 01/14/2023]
Abstract
This work reports on theeffect of heat treatment on the protein conformational stabilityof intact and post-translationallycleaved peanut allergen Ara h 6 in relation to IgE-binding. Intact and post-translationallycleaved Ara h 6 are structurally similar and theirstrong resistance to denaturant-inducedunfolding is comparable. Only upon exposure toautoclave conditions the twoforms of Ara h 6 demonstrated susceptibility toirreversible denaturationresulting in a significant decrease in IgE-binding potency. Thisreduction isfor the intact protein more pronounced than for than for the cleaved form. This isattributed to less conformational constrains of the cleaved form comparedtointact, as suggested by the 2-fold lower activation energy for unfoldingfound for the cleavedform. Overall, harsh conditionsare required to denature Ara h 6 and to significantly reduce its IgE-bindingpotency. The cleavedform possesses more resistance to such denaturation than the intactform.
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Affiliation(s)
| | | | - Danijela Apostolovic
- Clinical Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Solnavägen 1, 171 77 Solna, Sweden
| | - 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
| | - Joseph L Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - 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.
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18
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Pandey AK, Sudini HK, Upadhyaya HD, Varshney RK, Pandey MK. Hypoallergen Peanut Lines Identified Through Large-Scale Phenotyping of Global Diversity Panel: Providing Hope Toward Addressing One of the Major Global Food Safety Concerns. Front Genet 2019; 10:1177. [PMID: 31827488 PMCID: PMC6890724 DOI: 10.3389/fgene.2019.01177] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/24/2019] [Indexed: 01/14/2023] Open
Abstract
Peanut allergy is one of the serious health concern and affects more than 1% of the world's population mainly in Americas, Australia, and Europe. Peanut allergy is sometimes life-threatening and adversely affect the life quality of allergic individuals and their families. Consumption of hypoallergen peanuts is the best solution, however, not much effort has been made in this direction for identifying or developing hypoallergen peanut varieties. A highly diverse peanut germplasm panel was phenotyped using a recently developed monoclonal antibody-based ELISA protocol to quantify five major allergens. Results revealed a wide phenotypic variation for all the five allergens studied i.e., Ara h 1 (4-36,833 µg/g), Ara h 2 (41-77,041 µg/g), Ara h 3 (22-106,765 µg/g), Ara h 6 (829-103,892 µg/g), and Ara h 8 (0.01-70.12 µg/g). The hypoallergen peanut genotypes with low levels of allergen proteins for Ara h 1 (4 µg/g), Ara h 2 (41 µg/g), Ara h 3 (22 µg/g), Ara h 6 (829 µg/g), and Ara h 8 (0.01 µg/g) have paved the way for their use in breeding and genomics studies. In addition, these hypoallergen peanut genotypes are available for use in cultivation and industry, thus opened up new vistas for fighting against peanut allergy problem across the world.
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Affiliation(s)
| | | | | | | | - Manish K. Pandey
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
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19
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Yu J, Mikiashvili N. Effectiveness of different proteases in reducing allergen content and IgE-binding of raw peanuts. Food Chem 2019; 307:125565. [PMID: 31630022 DOI: 10.1016/j.foodchem.2019.125565] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/30/2019] [Accepted: 09/17/2019] [Indexed: 12/20/2022]
Abstract
The effectiveness of some non-specific proteases in reducing raw peanut allergenicity was investigated. Peanut kernels were treated by Alcalase, papain, Neutrase and bromelain, respectively. The residues of major peanut allergens Ara h 1, Ara h 2 and Ara h 6 were determined by sandwich ELISA and SDS-PAGE, and the allergenicities of treated peanuts were compared to that of untreated peanuts by western blot. All tested proteases were effective in reducing Ara h 1, but their effectiveness in hydrolyzing Ara h 2 and Ara h 6 varied greatly. The maximal reductions of extractable Ara h 1, Ara h 2 and Ara h 6 were 100%, 100% and 99.8%, respectively, achieved by Alcalase hydrolysis. Alcalase was more effective in overall allergenicity reduction; bromelain and Neutrase were the least effective in reducing Ara h 2 and Ara h 6, respectively. The hydrolysis of original allergens also produced some smaller peptides with strong IgE-binding.
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Affiliation(s)
- Jianmei Yu
- Department of Family and Consumer Sciences, North Carolina Agricultural and Technical State University, Greensboro, NC, USA.
| | - Nona Mikiashvili
- Department of Family and Consumer Sciences, North Carolina Agricultural and Technical State University, Greensboro, NC, USA
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20
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Sharma GM, Chatim A, Ferguson M, Williams KM. Extraction Conditions Affect the Immunoreactivity of Peanut Allergens. J Food Sci 2019; 84:2357-2363. [PMID: 31364176 DOI: 10.1111/1750-3841.14712] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 05/14/2019] [Accepted: 06/02/2019] [Indexed: 11/28/2022]
Abstract
Peanut allergic consumers rely on food package labels to avoid foods containing peanut. The inadvertent presence of peanut in foods due to cross-contact can be fatal if ingestion of such food leads to an allergic reaction. Analytical methods are available to detect undeclared peanut in foods. However, depending on the type of food matrix and food processing parameters, method performance can be adversely affected due to reduction in the extraction efficiency of peanut proteins. Temperature and probe sonication were used as a preincubation treatment for peanut flour slurries to assess their effect on the total peanut protein solubility from raw, light-roasted, and dark-roasted peanut flours. The effect of these treatments on the immunoreactivity of peanut allergens (Ara h 1, Ara h 2, Ara h 3, and Ara h 6) was determined by an indirect enzyme-linked immunosorbent assay using antibodies raised against these individual peanut proteins. Preincubation at 50 °C did not significantly improve the peanut protein solubility, whereas an increase in protein solubility was observed when light- and dark-roasted peanut flour slurries were preincubated at 90 °C or sonicated. The immunoreactivity of peanut allergens varied depending on the degree of peanut flour roasting and type of preincubation treatment. Overall, the immunoreactivity of peanut allergens from most peanut flour slurries was unaffected when preincubated at 50 °C for up to 60 min or sonicated with a probe for up to 5 min, whereas preincubation at 90 °C resulted in a time-dependent reduction in immunoreactivity of peanut allergens. Sonication treatment may improve peanut protein extraction without markedly affecting their immunoreactivity. PRACTICAL APPLICATION: Extraction of peanut proteins is vital for developed analytical methods to estimate peanut allergens in foods. The manuscript describes the effect of two different temperatures (50 and 90 °C) and probe-type sonication on peanut protein solubility. The findings suggest sonication can improve peanut protein solubility without markedly affecting their immunoreactivity.
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Affiliation(s)
- Girdhari M Sharma
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD
| | - Ajay Chatim
- Joint Inst. for Food Safety and Applied Nutrition, Univ. of Maryland, College Park, MD
| | - Martine Ferguson
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD
| | - Kristina M Williams
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD
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21
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Shah F, Shi A, Ashley J, Kronfel C, Wang Q, Maleki SJ, Adhikari B, Zhang J. Peanut Allergy: Characteristics and Approaches for Mitigation. Compr Rev Food Sci Food Saf 2019; 18:1361-1387. [DOI: 10.1111/1541-4337.12472] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 05/19/2019] [Accepted: 05/22/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Faisal Shah
- Inst. of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key research Laboratory of Agro‐Products ProcessingMinistry of Agriculture Beijing 100193 P. R. China
| | - Aimin Shi
- Inst. of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key research Laboratory of Agro‐Products ProcessingMinistry of Agriculture Beijing 100193 P. R. China
| | - Jon Ashley
- International Iberian Nanotechnology LaboratoryFood Quality and Safety Research group Berga 4715‐330 Portugal
| | - Christina Kronfel
- Food Processing and Sensory Quality ResearchUnited States Dept. of Agriculture New Orleans LA 70124 USA
| | - Qiang Wang
- Inst. of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key research Laboratory of Agro‐Products ProcessingMinistry of Agriculture Beijing 100193 P. R. China
| | - Soheila J. Maleki
- Food Processing and Sensory Quality ResearchUnited States Dept. of Agriculture New Orleans LA 70124 USA
| | - Benu Adhikari
- School of ScienceRMIT Univ. Melbourne VIC 3083 Australia
| | - Jinchuang Zhang
- Inst. of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key research Laboratory of Agro‐Products ProcessingMinistry of Agriculture Beijing 100193 P. R. China
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22
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Hazebrouck S, Guillon B, Paty E, Dreskin SC, Adel-Patient K, Bernard H. Variable IgE cross-reactivity between peanut 2S-albumins: The case for measuring IgE to both Ara h 2 and Ara h 6. Clin Exp Allergy 2019; 49:1107-1115. [PMID: 31108010 DOI: 10.1111/cea.13432] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/15/2019] [Accepted: 04/25/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND 2S-albumins Ara h 2 and Ara h 6 are the most potent peanut allergens and levels of specific immunoglobulin E (IgE) towards these proteins are good predictors of clinical reactivity. Because of structural homologies, Ara h 6 is generally considered to cross-react extensively with Ara h 2. OBJECTIVE We aimed to quantify the IgE cross-reactivity between Ara h 2 and Ara h 6. METHODS Peanut 2S-albumins were purified from raw peanuts. The IgE cross-reactivity between Ara h 2 and Ara h 6 was evaluated with 32 sera from French and US peanut-allergic patients by measuring the residual IgE-binding to one 2S-albumin after depletion of IgE antibodies recognizing the other 2S-albumin. The IgE cross-reactivity between Ara h 2 and Ara h 6 was further investigated by competitive inhibition of IgE-binding and by a model of mast cell degranulation. RESULTS A highly variable level of IgE cross-reactivity was revealed among the patients. The mean fraction of cross-reactive IgE antibodies represented only 17.1% of 2S-albumins-specific IgE antibodies and was lower than the mean fraction of IgE specific to Ara h 2 (57.4%) or to Ara h 6 (25.5%). The higher level of Ara h 2-specific IgE was principally due to the IgE-binding capacity of an insertion containing the repeated immunodominant linear epitope DPYSPOH S. The impact of IgE cross-reactivity on diagnostic testing was illustrated with a serum displaying an Ara h 6-specific IgE response of 26 UI/mL that was not associated with the capacity of Ara h 6 to trigger mast cell degranulation. CONCLUSIONS & CLINICAL RELEVANCE Immunoglobulin E antibodies specific to peanut 2S-albumins are mainly non-cross-reactive, but low-affinity cross-reactivity can affect diagnostic accuracy. Testing IgE-binding to a mixture of 2S-albumins rather than to each separately may enhance diagnostic performance.
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Affiliation(s)
- Stéphane Hazebrouck
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Blanche Guillon
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Evelyne Paty
- Université Paris Descartes-Assistance Publique des Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, Denver School of Medicine, University of Colorado, Aurora, Colorado
| | - Karine Adel-Patient
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Hervé Bernard
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
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Pandey AK, Varshney RK, Sudini HK, Pandey MK. An Improved Enzyme-Linked Immunosorbent Assay (ELISA) Based Protocol Using Seeds for Detection of Five Major Peanut Allergens Ara h 1, Ara h 2, Ara h 3, Ara h 6, and Ara h 8. Front Nutr 2019; 6:68. [PMID: 31231654 PMCID: PMC6560202 DOI: 10.3389/fnut.2019.00068] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/25/2019] [Indexed: 02/05/2023] Open
Abstract
Peanut allergy is an important health concern among many individuals. As there is no effective treatment to peanut allergy, continuous monitoring of peanut-based products, and their sources is essential. Precise detection of peanut allergens is key for identification and development of improved peanut varieties with minimum or no allergens in addition to estimating the levels in peanut-based products available in food chain. The antibody based ELISA protocol along with sample preparation was standardized for Ara h 1, Ara h 2, Ara h 3, Ara h 6, and Ara h 8 to estimate their quantities in peanut seeds. Three different dilutions were optimized to precisely quantify target allergen proteins in peanut seeds such as Ara h 1 (1/1,000, 1/2,000, and 1/4,000), Ara h 2 and Ara h 3 (1/5,000, 1/10,000, and 1/20,000), Ara h 6 (1/40,000, 1/80,000, and 1/1,60,000), and Ara h 8 (1/10, 1/20, and 1/40). These dilutions were finalized for each allergen based on the accuracy of detection by achieving <20% coefficient of variation in three technical replicates. This protocol captured wide variation of allergen proteins in selected peanut genotypes for Ara h 1 (77-46,106 μg/g), Ara h 2 (265-5,426 μg/g), Ara h 3 (382-12,676 μg/g), Ara h 6 (949-43,375 μg/g), and Ara h 8 (0.385-6 μg/g). The assay is sensitive and reliable in precise detection of five major peanut allergens in seeds. Deployment of such protocol allows screening of large scale germplasm and breeding lines while developing peanut varieties with minimum allergenicity to ensure food safety.
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Affiliation(s)
| | | | - Hari K. Sudini
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Manish K. Pandey
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
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24
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25
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Epicutaneous immunotherapy for peanut allergy modifies IgG4 responses to major peanut allergens. J Allergy Clin Immunol 2019; 143:1218-1221.e4. [DOI: 10.1016/j.jaci.2018.10.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 10/08/2018] [Accepted: 10/12/2018] [Indexed: 11/20/2022]
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26
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Bueno‐Díaz C, Martín‐Pedraza L, Benedé S, Haroun‐Díaz E, las Heras M, Batanero E, Cuesta‐Herranz J, Villalba M. Seed storage 2S albumins are predictive indicators of exclusive Anacardiaceae cross‐reactivity. Clin Exp Allergy 2019; 49:545-549. [DOI: 10.1111/cea.13357] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 12/19/2018] [Accepted: 01/09/2019] [Indexed: 01/05/2023]
Affiliation(s)
- Cristina Bueno‐Díaz
- Department of Biochemistry and Molecular BiologyUniversidad Complutense de Madrid Madrid Spain
| | - Laura Martín‐Pedraza
- Department of Biochemistry and Molecular BiologyUniversidad Complutense de Madrid Madrid Spain
| | - Sara Benedé
- Department of Biochemistry and Molecular BiologyUniversidad Complutense de Madrid Madrid Spain
| | | | | | - Eva Batanero
- Department of Biochemistry and Molecular BiologyUniversidad Complutense de Madrid Madrid Spain
| | | | - Mayte Villalba
- Department of Biochemistry and Molecular BiologyUniversidad Complutense de Madrid Madrid Spain
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27
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Hemmings O, Kwok M, McKendry R, Santos AF. Basophil Activation Test: Old and New Applications in Allergy. Curr Allergy Asthma Rep 2018; 18:77. [PMID: 30430289 PMCID: PMC6244909 DOI: 10.1007/s11882-018-0831-5] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE OF REVIEW The basophil activation test (BAT) using flow cytometry has supplanted traditional methods of measuring basophil degranulation using histamine and other mediator release, and can be used for clinical applications as well as to explore the immune mechanisms of effector cell response to allergen. This review discusses the advancements made in clinical, diagnostic and laboratory research of allergy utilizing an ever-evolving BAT. RECENT FINDINGS Being an in vitro surrogate of the allergic reaction that happens in vivo in the sick patient, the BAT can be used to support the diagnosis of various allergic conditions, such as food, drug, respiratory and insect venom allergies, and the assessment of clinical response to allergen-specific immunotherapy and other immunomodulatory treatments. The BAT can also be used for research purposes to explore the mechanisms of allergy and tolerance at the level of the basophil, for instance by manipulating IgE and IgG and their receptors and by studying intracellular signalling cascade in response to allergen. This review covers the applications of the BAT to the clinical management of allergic patients and the increased understanding of the mechanisms of immune response to allergens as well as technological advancements made in recent years.
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Affiliation(s)
- Oliver Hemmings
- Department of Women and Children's Health (Paediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
| | - Matthew Kwok
- Department of Women and Children's Health (Paediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
| | - Richard McKendry
- Department of Women and Children's Health (Paediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK
| | - Alexandra F Santos
- Department of Women and Children's Health (Paediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK. .,Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK. .,MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK. .,Children's Allergies Department, Guy's and St. Thomas' NHS Foundation Trust, St. Thomas' Hospital, Westminster Bridge Road, London, UK.
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28
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Datema MR, Eller E, Zwinderman AH, Poulsen LK, Versteeg SA, van Ree R, Bindslev-Jensen C. Ratios of specific IgG 4 over IgE antibodies do not improve prediction of peanut allergy nor of its severity compared to specific IgE alone. Clin Exp Allergy 2018; 49:216-226. [PMID: 30269403 PMCID: PMC7379576 DOI: 10.1111/cea.13286] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 07/15/2018] [Accepted: 08/01/2018] [Indexed: 01/04/2023]
Abstract
Background IgG4 antibodies have been suggested to play a protective role in the translation of peanut sensitization into peanut allergy. Whether they have added value as diagnostic read‐out has not yet been reported. Objective To evaluate whether (a) peanut‐specific IgG, IgG4 and/or IgA antibodies are associated with tolerance and/or less severe reactions and (b) they can improve IgE‐based diagnostic tests. Methods Sera of 137 patients with challenge‐proven peanut allergy and of 25 subjects that tolerated peanut, both with known IgE profiles to peanut extract and five individual peanut allergens, were analyzed for specific IgG and IgG4. Antibody levels and ratios thereof were associated with challenge outcome including symptom severity grades. For comparison of the discriminative performance, receiver operating characteristic curve (ROC) analysis was used. Results IgE against Ara h 2 was significantly higher in allergic than in tolerant patients and associated with severity of reactions (P < 0.001) with substantial diagnostic capability (AUC 0.91, 95%CI 0.87‐0.96 and 0.80, 95%CI 0.73‐0.87, respectively). IgG and IgG4 were also positively associated albeit significantly weaker (AUCs from 0.65 to 0.72). On the other hand, ratios of IgG and IgG4 over IgE were greater in patients that were tolerant or had mild symptoms as compared to severe patients but they did not predict challenge outcomes better than IgE alone (AUCs from 0.54 to 0.89). Conclusion IgE against Ara h 2 is the best biomarker for predicting peanut challenge outcomes including severity and IgG and IgG4 antibody ratios over IgE do not improve these outcomes.
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Affiliation(s)
- Mareen R Datema
- Department of Experimental Immunology, Academic Medical Center, Amsterdam, the Netherlands.,Department of Clinical Epidemiology, Academic Medical Centre, Biostatistics and Bioinformatics, Amsterdam, the Netherlands
| | - Esben Eller
- Department of Dermatology and Allergy Center, Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark
| | - Aeilko H Zwinderman
- Department of Clinical Epidemiology, Academic Medical Centre, Biostatistics and Bioinformatics, Amsterdam, the Netherlands
| | - Lars K Poulsen
- Allergy Clinic, Copenhagen University Hospital at Gentofte, Copenhagen, Denmark
| | - Serge A Versteeg
- Department of Experimental Immunology, Academic Medical Center, Amsterdam, the Netherlands
| | - Ronald van Ree
- Department of Experimental Immunology, Academic Medical Center, Amsterdam, the Netherlands.,Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, the Netherlands
| | - Carsten Bindslev-Jensen
- Department of Dermatology and Allergy Center, Odense Research Center for Anaphylaxis (ORCA), Odense University Hospital, Odense, Denmark
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29
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Bublin M, Kostadinova M, Radauer C, Varga EM, Hafner C, Schmidthaler K, Saidova A, Maleki SJ, Szépfalusi Z, Eiwegger T, Breiteneder H. Engineering of structural variants of the major peanut allergens Ara h 2 and Ara h 6 for allergen-specific immunotherapy. J Allergy Clin Immunol 2018; 143:1226-1229.e10. [PMID: 30414861 DOI: 10.1016/j.jaci.2018.10.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/27/2018] [Accepted: 10/12/2018] [Indexed: 10/27/2022]
Affiliation(s)
- Merima Bublin
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Maria Kostadinova
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Christian Radauer
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Eva-Maria Varga
- Department of Pediatrics, Respiratory and Allergic Disease Division, Medical University of Graz, Graz, Austria
| | - Christine Hafner
- Department of Dermatology, University Hospital St Poelten, Karl Landsteiner University of Health Sciences, St Poelten, Austria; Karl Landsteiner Institute for Dermatological Research, St Poelten, Austria
| | - Klara Schmidthaler
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Aziza Saidova
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Soheila J Maleki
- US Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, La
| | - Zsolt Szépfalusi
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
| | - Thomas Eiwegger
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria; Division of Immunology and Allergy, Food Allergy and Anaphylaxis Program, The Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada; Research Institute, The Hospital for Sick Children, Translational Medicine Program, Toronto, Ontario, Canada; Department of Immunology, The University of Toronto, Toronto, Ontario, Canada.
| | - Heimo Breiteneder
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
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30
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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. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 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] [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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31
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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] [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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32
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Yin HY, Fang TJ, Li YT, Fung YF, Tsai WC, Dai HY, Wen HW. Rapidly detecting major peanut allergen-Ara h2 in edible oils using a new immunomagnetic nanoparticle-based lateral flow assay. Food Chem 2018; 271:505-515. [PMID: 30236709 DOI: 10.1016/j.foodchem.2018.07.064] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 06/12/2018] [Accepted: 07/11/2018] [Indexed: 12/20/2022]
Abstract
Ara h2 is a major peanut allergen that induces rashes, vomiting, diarrhea, and anaphylactic shock. Since peanut is a major source in producing edible oils globally, Ara h2 residues can be present in various edible oils. In this work, an immunomagnetic nanoparticle-based lateral flow assay for identifying Ara h2 in edible oils is developed. This assay exhibits high sensitivity with a visual detection limit of 0.1 mg/kg Ara h2 in oil, and favorable specificity in differentiating peanut from seeds and nuts. The calculated CV values of intra- and inter-assay were 6.73-10.21% and 4.75-8.57%, respectively, indicating high reproducibility. In an analysis of 26 oil products, Ara h2 was detected in two peanut oils as 0.122 ± 0.026 mg/kg and 0.247 ± 0.027 mg/kg. The entire method takes 5 h, including a 3.5-h sample preparation. Hence, this method has the potential to be an effective way to screen edible oils for Ara h2.
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Affiliation(s)
- Hsin-Yi Yin
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Tony J Fang
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan, ROC; Food Industry Research and Development Institute, Hsinchu, Taiwan, ROC.
| | - Yi-Ting Li
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Yang-Fan Fung
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Wen-Che Tsai
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Hong-Yu Dai
- Crop Science Division and Guansi Experiment Station, Taiwan Agricultural Research Institute, Council of Agriculture, Executive Yuan, Taichung, Taiwan, ROC.
| | - Hsiao-Wei Wen
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan, ROC.
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33
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Abstract
Peanut allergens have the potential to negatively impact on the health and quality of life of millions of consumers worldwide. The seeds of the peanut plant Arachis hypogaea contain an array of allergens that are able to induce the production of specific IgE antibodies in predisposed individuals. A lot of effort has been focused on obtaining the sequences and structures of these allergens due to the high health risk they represent. At present, 16 proteins present in peanuts are officially recognized as allergens. Research has also focused on their in-depth immunological characterization as well as on the design of modified hypoallergenic derivatives for potential use in clinical studies and the formulation of strategies for immunotherapy. Detailed research protocols are available for the purification of natural allergens as well as their recombinant production in bacterial, yeast, insect, and algal cells. Purified allergen molecules are now routinely used in diagnostic multiplex protein arrays for the detection of the presence of allergen-specific IgE. This review gives an overview on the wealth of knowledge that is available on individual peanut allergens.
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Affiliation(s)
- Chiara Palladino
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Heimo Breiteneder
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
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34
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Hayen SM, Ehlers AM, den Hartog Jager CF, Garssen J, Knol EF, Knulst AC, Suer W, Willemsen LEM, Otten HG. 2S protein Ara h 7.0201 has unique epitopes compared to other Ara h 7 isoforms and is comparable to 2S proteins Ara h 2 and 6 in basophil degranulation capacity. Clin Exp Allergy 2018. [DOI: 10.1111/cea.13134] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. M. Hayen
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - A. M. Ehlers
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - C. F. den Hartog Jager
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - J. Garssen
- Division of Pharmacology; Utrecht Institute for Pharmaceutical Sciences; Faculty of Science; Utrecht University; Utrecht The Netherlands
- Immunology; Nutricia Research; Utrecht The Netherlands
| | - E. F. Knol
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | - A. C. Knulst
- Department of Dermatology/Allergology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
| | | | - L. E. M. Willemsen
- Division of Pharmacology; Utrecht Institute for Pharmaceutical Sciences; Faculty of Science; Utrecht University; Utrecht The Netherlands
| | - H. G. Otten
- Laboratory of Translational Immunology; University Medical Center Utrecht; Utrecht University; Utrecht The Netherlands
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35
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Blankestijn MA, Knulst AC, Knol EF, Le TM, Rockmann H, Otten HG, Klemans RJB. Sensitization to PR-10 proteins is indicative of distinctive sensitization patterns in adults with a suspected food allergy. Clin Transl Allergy 2017; 7:42. [PMID: 29201345 PMCID: PMC5700688 DOI: 10.1186/s13601-017-0177-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/31/2017] [Indexed: 11/30/2022] Open
Abstract
Background The extent of co-sensitization within and between food protein families in an adult population is largely unknown. This study aimed to identify the most frequently recognized components in the PR-10 and storage protein family, as well as patterns in (co-)sensitization, in a birch-endemic area. Methods Results of ImmunoCAP ISAC, performed during routine care in Dutch adult outpatients suspected of food allergy, were collected. Results A total of 305 patients were selected, aged 16–79 years (median 32 years). Sensitization to one or more PR-10 proteins was most frequent (74% of all subjects), followed by 35% to storage protein and 15% to nsLTPs. Within the PR-10 family, subjects were most often sensitized to Bet v 1 (73% of 305), Cor a 1.04 (72%) and Mal d 1 (68%). Sensitization to PR-10s from soy, celery and kiwi occurred distinctively less often (< 55% of Bet v 1 sensitized subjects) compared to other food PR-10s (all > 70%). Subjects sensitized to these ‘less common PR-10 proteins’ were sensitized to more food and inhalant components on the ISAC, compared to subjects sensitized to ‘common PR-10 proteins’ (median 22 vs 13 out of 112, p < 0.0001). Seven subjects demonstrated sensitization to food PR-10 proteins, without concomitant sensitization to pollen PR-10s. Within the storage proteins, sensitization to multiple peanut allergens was most common (on average 3 out of 4). Conclusions Sensitization to PR-10 food proteins could occur without concomitant sensitization to common PR-10 from pollen in a subset of subjects. Less commonly recognized PR-10 proteins appear to be an indication of polysensitization. Electronic supplementary material The online version of this article (10.1186/s13601-017-0177-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mark A Blankestijn
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - André C Knulst
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Edward F Knol
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.,Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Thuy-My Le
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Heike Rockmann
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Henny G Otten
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Rob J B Klemans
- Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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Affiliation(s)
- Ondulla T. Toomer
- United States Department of Agriculture-Agricultural Research Service, Market Quality and Handling Research Unit, Raleigh, NC, USA
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Schocker F, Scharf A, Kull S, Jappe U. Detection of the Peanut Allergens Ara h 2 and Ara h 6 in Human Breast Milk: Development of 2 Sensitive and Specific Sandwich ELISA Assays. Int Arch Allergy Immunol 2017; 174:17-25. [PMID: 28950267 DOI: 10.1159/000479388] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/10/2017] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Little is known about breast milk as a vehicle for tolerance development or sensitization to peanuts very early in life. Thus, well-characterized and highly sensitive detection systems for the reliable determination of peanut allergens in breast milk are mandatory. METHODS For the quantification of the marker allergens Ara h 2 and Ara h 6 in the low nanogram per milliliter range in breast milk samples of a German cohort, sensitive and highly specific sandwich ELISAs were optimized and validated. RESULTS The Ara h 2 ELISA revealed a limit of detection (LOD) of 1.3 ng Ara h 2/mL and a quantification range of 2.3-250 ng/mL, the Ara h 6 ELISA showed an LOD of 0.7 ng/mL and a working range of 1.1-14.4 ng/mL. The assays showed no relevant cross-reactivity against other potentially cross-reactive legume, seed, and tree nut extracts (<0.01%, except for Ara h 1 in the Ara h 2 ELISA <0.1%). Ara h 2 was detectable in breast milk samples from 14/40 (35%) of the participants in concentrations from 2.3 to 184 ng/mL, Ara h 6 appeared in 9/40 (22.5%) of the lactating mothers between 1.1 and 9.7 ng/mL, and 1 highly positive sample with 79 ng/mL. Both allergens appeared at the same time points, but Ara h 6 in lower concentrations than Ara h 2. CONCLUSIONS Sensitive and specific diagnostic tools for the determination of Ara h 2 and Ara h 6 in human breast milk were established. The kinetics of secreted Ara h 2 and Ara h 6 seem to be similar but with a difference in concentration. Follow-up investigations on their tolerogenic or sensitizing properties in breast milk become now accessible.
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Affiliation(s)
- Frauke Schocker
- Division of Clinical and Molecular Allergology, Research Center Borstel, Priority Research Area Asthma and Allergy, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany
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Deak PE, Vrabel MR, Kiziltepe T, Bilgicer B. Determination of Crucial Immunogenic Epitopes in Major Peanut Allergy Protein, Ara h2, via Novel Nanoallergen Platform. Sci Rep 2017; 7:3981. [PMID: 28638052 PMCID: PMC5479826 DOI: 10.1038/s41598-017-04268-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 05/10/2017] [Indexed: 12/16/2022] Open
Abstract
Current methods for detection and diagnosis of allergies do not provide epitope specific immunogenic information and hence lack critical information that could aid in the prediction of clinical responses. To address this issue, we developed a nanoparticle based platform, called nanoallergens that enable multivalent display of potential allergy epitopes for determining the immunogenicity of each IgE binding epitope. By synthesizing nanoallergens that present various epitopes from the major peanut allergen, Ara h2, we directly determined the immunogenicity of each epitope, alone and in combination with other epitopes, using patient sera. This information provided insights on which epitopes are most critical for physiological responses to Ara h2 and revealed the importance of both high and low affinity epitopes for allergic responses. We anticipate the nanoallergen platform to be used to provide information regarding allergic reactions and therefore potentially aid in more accurate diagnosis and design of personalized treatment options.
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Affiliation(s)
- Peter E Deak
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Maura R Vrabel
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Tanyel Kiziltepe
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA
- Advanced Diagnostics and Therapeutics, University of Notre Dame, Notre Dame, IN, 46556, USA
| | - Basar Bilgicer
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN, 46556, USA.
- Advanced Diagnostics and Therapeutics, University of Notre Dame, Notre Dame, IN, 46556, USA.
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA.
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Vanga SK, Raghavan V. Processing effects on tree nut allergens: A review. Crit Rev Food Sci Nutr 2017; 57:3794-3806. [DOI: 10.1080/10408398.2016.1175415] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sai Kranthi Vanga
- Department of Bioresource Engineering, Faculty of Agriculture and Environmental Studies, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Vijaya Raghavan
- Department of Bioresource Engineering, Faculty of Agriculture and Environmental Studies, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
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Negi SS, Braun W. Cross-React: a new structural bioinformatics method for predicting allergen cross-reactivity. Bioinformatics 2017; 33:1014-1020. [PMID: 28062447 DOI: 10.1093/bioinformatics/btw767] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 12/01/2016] [Indexed: 11/14/2022] Open
Abstract
The phenomenon of cross-reactivity between allergenic proteins plays an important role to understand how the immune system recognizes different antigen proteins. Allergen proteins are known to cross-react if their sequence comparison shows a high sequence identity which also implies that the proteins have a similar 3D fold. In such cases, linear sequence alignment methods are frequently used to predict cross-reactivity between allergenic proteins. However, the prediction of cross-reactivity between distantly related allergens continues to be a challenging task. To overcome this problem, we developed a new structure-based computational method, Cross-React, to predict cross-reactivity between allergenic proteins available in the Structural Database of Allergens (SDAP). Our method is based on the hypothesis that we can find surface patches on 3D structures of potential allergens with amino acid compositions similar to an epitope in a known allergen. We applied the Cross-React method to a diverse set of seven allergens, and successfully identified several cross-reactive allergens with high to moderate sequence identity which have also been experimentally shown to cross-react. Based on these findings, we suggest that Cross-React can be used as a predictive tool to assess protein allergenicity and cross-reactivity. Availability and Implementation : Cross-React is available at: http://curie.utmb.edu/Cross-React.html. Contact ssnegi@utmb.edu.
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Alves RC, Pimentel FB, Nouws HP, Silva TH, Oliveira MBP, Delerue-Matos C. Improving the extraction of Ara h 6 (a peanut allergen) from a chocolate-based matrix for immunosensing detection: Influence of time, temperature and additives. Food Chem 2017; 218:242-248. [DOI: 10.1016/j.foodchem.2016.09.085] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Revised: 07/11/2016] [Accepted: 09/14/2016] [Indexed: 12/22/2022]
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Chen X, Dreskin SC. Application of phage peptide display technology for the study of food allergen epitopes. Mol Nutr Food Res 2017; 61. [PMID: 27995755 DOI: 10.1002/mnfr.201600568] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 11/09/2016] [Accepted: 12/05/2016] [Indexed: 12/16/2022]
Abstract
Phage peptide display technology has been used to identify IgE-binding mimotopes (mimics of natural epitopes) that mimic conformational epitopes. This approach is effective in the characterization of those epitopes that are important for eliciting IgE-mediated allergic responses by food allergens and those that are responsible for cross-reactivity among allergenic food proteins. Application of this technology will increase our understanding of the mechanisms whereby food allergens elicit allergic reactions, will facilitate the discovery of diagnostic reagents and may lead to mimotope-based immunotherapy.
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Affiliation(s)
- Xueni Chen
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
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Schmidt-Hieltjes Y, Teodorowicz M, Jansen A, den Hartog G, Elfvering-Berendsen L, de Jong NW, Savelkoul HFJ, Ruinemans-Koerts J. An alternative inhibition method for determining cross-reactive allergens. Clin Chem Lab Med 2017; 55:248-253. [PMID: 27474838 DOI: 10.1515/cclm-2016-0172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/24/2016] [Indexed: 11/15/2022]
Abstract
BACKGROUND Inhibition assays are an useful tool to identify the allergen of primary sensitization of cross-reactive allergens. Classical ELISA-based inhibition assays are limited by both the availability of commercial standardized allergen extracts and the experience and knowledge needed for making home-made extracts. Moreover the direct comparison of the inhibition ELISAs outcomes between different laboratories is difficult because of different sources of used allergen extracts and a number of methodological variations. Therefore, we propose a novel ImmunoCap (Phadia, Thermofisher Scientific) based immunoinhibition method with the use of commercially available Caps as the allergen source. METHODS The novel ImmunoCap based immunoinhibition method was developed and tested with sera from patients with a well-known cross-reactive sensitization for fig (Ficus carica) and ficus (Ficus benjamina). Results were compared with a classically applied inhibition method, i.e. addition of homemade allergen extract to patient serum. RESULTS The amount of allergens (fig and ficus extracts) needed to reach a similar degree of inhibition was comparable for both inhibition methods. CONCLUSIONS The ImmunoCap based inhibition assay, in addition to classical inhibition methods, is a valuable tool as the ImmunoCap analyzer and commercial allergens (Caps) are more widely available which makes the outcomes of inhibition tests comparable between different laboratories. Furthermore, in the ImmunoCap inhibition method the same protein source is used for both the inhibition of sIgE and sIgE measurement, which might be even more relevant when multiple cross-reactive allergens are tested.
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Wu Z, Zhang Y, Zhan S, Lian J, Zhao R, Li K, Tong P, Li X, Yang A, Chen H. Development of immunoaffinity chromatographic method for Ara h 2 isolation. Protein Expr Purif 2016; 131:85-90. [PMID: 27989798 DOI: 10.1016/j.pep.2016.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 10/20/2022]
Abstract
Ara h 2 is considered a major allergen in peanut. Due to the difficulty of separation, Ara h 2 had not been fully studied. Immunoaffinity chromatography (IAC) column can separate target protein with high selectivity, which made it possible to purify Ara h 2 from different samples. In this study, IAC method was developed to purify Ara h 2 and its effect was evaluated. By coupling polyclonal antibody (pAb) on CNBr-activated Sepharose 4B, the column for specific extraction was constructed. The coupling efficiency of the IAC column was higher than 90%, which made the capacity of column reached 0.56 mg per 0.15 g medium (dry weight). The recovery of Ara h 2 ranged from 93% to 100% for different concentrations of pure Ara h 2 solutions in 15 min. After using a column 10 times, about 88% of the column capacity remained. When applied to extract Ara h 2 from raw peanut protein extract and boiled peanut protein extract, the IAC column could recovery 94% and 88% target protein from the mixture. SDS-PAGE and Western blotting analysis confirmed the purified protein was Ara h 2, its purity reached about 90%. Significantly, the IAC column could capture dimer of Ara h 2, which made it feasible to prepared derivative of protein after processing.
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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.
| | - Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Food Science & Technology, Nanchang University, Nanchang 330047, China
| | - Shaode Zhan
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Food Science & Technology, Nanchang University, Nanchang 330047, China
| | - Jun Lian
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Food Science & Technology, Nanchang University, Nanchang 330047, China
| | - Ruifang Zhao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Food Science & Technology, Nanchang University, Nanchang 330047, China
| | - Kun Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Resources Environment & Chemical Engineering, Nanchang University, Nanchang 330047, China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Food Science & Technology, Nanchang University, Nanchang 330047, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; School of Food Science & Technology, 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
| | - 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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Detection of peanut allergen in human blood after consumption of peanuts is skewed by endogenous immunoglobulins. J Immunol Methods 2016; 440:52-57. [PMID: 27845035 DOI: 10.1016/j.jim.2016.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 11/07/2016] [Accepted: 11/08/2016] [Indexed: 12/16/2022]
Abstract
Some studies have suggested that allergens may appear in the circulation after ingestion of allergenic food sources. The reported levels of allergen in serum, however, are low, and conclusions between studies differ. Here, we investigated factors that determine the detection of allergens in serum after consumption of peanuts. Ten healthy volunteers ingested 100g of light-roasted peanuts. Serum samples were taken at regular intervals for six hours. A double monoclonal sandwich ELISA was used to analyse the presence and quantity of the major peanut allergen Ara h 6 in serum. In 4 out of 10 subjects, no Ara h 6 could be detected. Purified Ara h 6 that was digested in vitro was still reactive in the ELISA, rejecting the possibility that digestion leads to small peptides that could not be detected. Spiking of purified Ara h 6 in baseline serum showed that the pre-ingestion serum of these four subjects partially prevented Ara h 6 to react in the ELISA, with a reduction of reactivity of up to 3 orders of magnitude or more. Pre-ingestion serum of the other six subjects did not show such an effect. The reduction of reactivity of Ara h 6 coincided with high titres of IgG and IgG4, and removal of IgG from pre-ingestion serum abolished this effect completely, indicating that IgG and IgG4 inhibited the reactivity of Ara h6 in the ELISA. We conclude that some individuals have IgG and IgG4 against food allergens in their blood, which interferes with detection of such food allergens in serum. Because this effect does not occur for each individual, the possibility of such interference should be taken into consideration when interpreting immunochemical studies on the absorption of food allergens in serum.
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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] [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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The IgE and basophil responses to Ara h 2 and Ara h 6 are good predictors of peanut allergy in children. J Allergy Clin Immunol 2016; 139:358-360.e8. [PMID: 27516216 DOI: 10.1016/j.jaci.2016.06.041] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 06/21/2016] [Accepted: 06/27/2016] [Indexed: 11/21/2022]
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Conformational stability of digestion-resistant peptides of peanut conglutins reveals the molecular basis of their allergenicity. Sci Rep 2016; 6:29249. [PMID: 27377129 PMCID: PMC4932508 DOI: 10.1038/srep29249] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/13/2016] [Indexed: 12/14/2022] Open
Abstract
Conglutins represent the major peanut allergens and are renowned for their resistance to gastro-intestinal digestion. Our aim was to characterize the digestion-resistant peptides (DRPs) of conglutins by biochemical and biophysical methods followed by a molecular dynamics simulation in order to better understand the molecular basis of food protein allergenicity. We have mapped proteolysis sites at the N- and C-termini and at a limited internal segment, while other potential proteolysis sites remained unaffected. Molecular dynamics simulation showed that proteolysis only occurred in the vibrant regions of the proteins. DRPs appeared to be conformationally stable as intact conglutins. Also, the overall secondary structure and IgE-binding potency of DRPs was comparable to that of intact conglutins. The stability of conglutins toward gastro-intestinal digestion, combined with the conformational stability of the resulting DRPs provide conditions for optimal exposure to the intestinal immune system, providing an explanation for the extraordinary allergenicity of peanut conglutins.
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Chen X, Negi SS, Liao S, Gao V, Braun W, Dreskin SC. Conformational IgE epitopes of peanut allergens Ara h 2 and Ara h 6. Clin Exp Allergy 2016; 46:1120-1128. [PMID: 27238146 DOI: 10.1111/cea.12764] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/11/2016] [Accepted: 05/14/2016] [Indexed: 12/01/2022]
Abstract
BACKGROUND Cross-linking of IgE antibody by specific epitopes on the surface of mast cells is a prerequisite for triggering symptoms of peanut allergy. IgE epitopes are frequently categorized as linear or conformational epitopes. Although linear IgE-binding epitopes of peanut allergens have been defined, little is known about conformational IgE-binding epitopes. OBJECTIVE To identify clinically relevant conformational IgE epitopes of the two most important peanut allergens, Ara h 2 and Ara h 6, using phage peptide library. METHODS A phage 12mer peptide library was screened with allergen-specific IgE from 4 peanut-allergic patients. Binding of the mimotopes to IgE from a total of 29 peanut-allergic subjects was measured by ELISA. The mimotope sequences were mapped on the surface areas of Ara h 2 and Ara h 6 using EpiSearch. RESULTS Forty-one individual mimotopes were identified that specifically bind anti- Ara h 2/Ara h 6 IgE as well as rabbit anti-Ara h 2 and anti-Ara h 6 IgG. Sequence alignment showed that none of the mimotope sequences match a linear segment of the Ara h 2 or Ara h 6 sequences. EpiSearch analysis showed that all the mimotopes mapped to surface patches of Ara h 2 and Ara h 6. Eight of the mimotopes were recognized by more than 90% of the patients, suggesting immunodominance. Each patient had distinct IgE recognition patterns but the recognition frequency was not correlated to the concentration of peanut specific IgE or to clinical history. CONCLUSIONS The mimotopes identified in this study represent conformational epitopes. Identification of similar surface patches on Ara h 2 and Ara h 6 further underscores the similarities between these two potent allergens.
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Affiliation(s)
- Xueni Chen
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Sumei Liao
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
| | - Valerie Gao
- Molecular Cellular Developmental Biology, University of Colorado, Boulder, CO
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
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