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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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Min J, Keswani T, LaHood NA, Lytle IR, Marini-Rapoport O, Andrieux L, Sneed SL, Edwards LL, Petrovich RM, Perera L, Pomés A, Pedersen LC, Patil SU, Mueller GA. Design of an Ara h 2 hypoallergen from conformational epitopes. Clin Exp Allergy 2024; 54:46-55. [PMID: 38168500 PMCID: PMC10843581 DOI: 10.1111/cea.14433] [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: 08/24/2023] [Revised: 10/30/2023] [Accepted: 11/12/2023] [Indexed: 01/05/2024]
Abstract
INTRODUCTION Adverse reactions are relatively common during peanut oral immunotherapy. To reduce the risk to the patient, some researchers have proposed modifying the allergen to reduce IgE reactivity, creating a putative hypoallergen. Analysis of recently cloned human IgG from patients treated with peanut immunotherapy suggested that there are three common conformational epitopes for the major peanut allergen Ara h 2. We sought to test if structural information on these epitopes could indicate mutagenesis targets for designing a hypoallergen and evaluated the reduction in IgE binding via immunochemistry and a mouse model of passive cutaneous anaphylaxis (PCA). METHODS X-ray crystallography characterized the conformational epitopes in detail, followed by mutational analysis of key residues to modify monoclonal antibody (mAb) and serum IgE binding, assessed by ELISA and biolayer interferometry. A designed Ara h 2 hypoallergen was tested for reduced vascularization in mouse PCA experiments using pooled peanut allergic patient serum. RESULTS A ternary crystal structure of Ara h 2 in complex with patient antibodies 13T1 and 13T5 was determined. Site-specific mutants were designed that reduced 13T1, 13T5, and 22S1 mAbs binding by orders of magnitude. By combining designed mutations from the three major conformational bins, a hexamutant (Ara h 2 E46R, E89R, E97R, E114R, Q146A, R147E) was created that reduced IgE binding in serum from allergic patients. Further, in the PCA model where mice were primed with peanut allergic patient serum, reactivity upon allergen challenge was significantly decreased using the hexamutant. CONCLUSION These studies demonstrate that prior knowledge of common conformational epitopes can be used to engineer reduced IgE reactivity, an important first step in hypoallergen design.
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Affiliation(s)
- Jungki Min
- Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, NC, USA
| | - Tarun Keswani
- Center for Inflammatory and Immunology Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Nicole A. LaHood
- Center for Inflammatory and Immunology Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Isabelle R. Lytle
- Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, NC, USA
| | - Orlee Marini-Rapoport
- Center for Inflammatory and Immunology Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Léna Andrieux
- Center for Inflammatory and Immunology Diseases, Massachusetts General Hospital, Boston, MA, USA
- Master de Biologie, École Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Université de Lyon, 69342 Lyon Cedex 07, France
| | - Sunny L. Sneed
- Center for Inflammatory and Immunology Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Lori L. Edwards
- Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, NC, USA
| | - Robert M. Petrovich
- Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, NC, USA
| | - Lalith Perera
- Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, NC, USA
| | | | - Lars C. Pedersen
- Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, NC, USA
| | - Sarita U. Patil
- Center for Inflammatory and Immunology Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Geoffrey A. Mueller
- Genome Integrity and Structural Biology, National Institute of Environmental Health Sciences, NC, USA
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Croote D, Wong JJW, Pecalvel C, Leveque E, Casanovas N, Kamphuis JBJ, Creeks P, Romero J, Sohail S, Bedinger D, Nadeau KC, Chinthrajah RS, Reber LL, Lowman HB. Widespread monoclonal IgE antibody convergence to an immunodominant, proanaphylactic Ara h 2 epitope in peanut allergy. J Allergy Clin Immunol 2024; 153:182-192.e7. [PMID: 37748654 PMCID: PMC10766438 DOI: 10.1016/j.jaci.2023.08.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/25/2023] [Accepted: 08/31/2023] [Indexed: 09/27/2023]
Abstract
BACKGROUND Despite their central role in peanut allergy, human monoclonal IgE antibodies have eluded characterization. OBJECTIVE We sought to define the sequences, affinities, clonality, and functional properties of human monoclonal IgE antibodies in peanut allergy. METHODS We applied our single-cell RNA sequencing-based SEQ SIFTER discovery platform to samples from allergic individuals who varied by age, sex, ethnicity, and geographic location in order to understand commonalities in the human IgE response to peanut allergens. Select antibodies were then recombinantly expressed and characterized for their allergen and epitope specificity, affinity, and functional properties. RESULTS We found striking convergent evolution of IgE monoclonal antibodies (mAbs) from several clonal families comprising both memory B cells and plasmablasts. These antibodies bound with subnanomolar affinity to the immunodominant peanut allergen Ara h 2, specifically a linear, repetitive motif. Further characterization of these mAbs revealed their ability to single-handedly cause affinity-dependent degranulation of human mast cells and systemic anaphylaxis on peanut allergen challenge in humanized mice. Finally, we demonstrated that these mAbs, reengineered as IgGs, inhibit significant, but variable, amounts of Ara h 2- and peanut-mediated degranulation of mast cells sensitized with allergic plasma. CONCLUSIONS Convergent evolution of IgE mAbs in peanut allergy is a common phenomenon that can reveal immunodominant epitopes on major allergenic proteins. Understanding the functional properties of these molecules is key to developing therapeutics, such as competitive IgG inhibitors, that are able to stoichiometrically outcompete endogenous IgE for allergen and thereby prevent allergic cascade in cases of accidental allergen exposure.
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Affiliation(s)
| | | | - Cyprien Pecalvel
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), UMR 1291, University of Toulouse, INSERM, CNRS, Toulouse, France
| | - Edouard Leveque
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), UMR 1291, University of Toulouse, INSERM, CNRS, Toulouse, France
| | - Natacha Casanovas
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), UMR 1291, University of Toulouse, INSERM, CNRS, Toulouse, France
| | - Jasper B J Kamphuis
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), UMR 1291, University of Toulouse, INSERM, CNRS, Toulouse, France
| | | | | | | | | | - Kari C Nadeau
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif; Department of Medicine, Stanford University School of Medicine, Stanford, Calif
| | - Rebecca S Chinthrajah
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif; Department of Medicine, Stanford University School of Medicine, Stanford, Calif
| | - Laurent L Reber
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), UMR 1291, University of Toulouse, INSERM, CNRS, Toulouse, France
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Canon N, Schein CH, Braun W, Negi SS, Chen X, Kulis MD, Kim EH, Pathy V, Pozzoli M, Liu W, Dreskin SC. Alanine Scanning of the Unstructured Region of Ara h 2 and of a Related Mimotope Reveals Critical Amino Acids for IgE Binding. Mol Nutr Food Res 2023; 67:e2300134. [PMID: 37706599 PMCID: PMC10840829 DOI: 10.1002/mnfr.202300134] [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: 03/09/2023] [Revised: 07/26/2023] [Indexed: 09/15/2023]
Abstract
SCOPE The unstructured region of Ara h 2, referred to as epitope 3, contains a repeated motif, DYPSh (h = hydroxyproline) that is important for IgE binding. METHODS AND RESULTS IgE binding assays to 20mer and shorter peptides of epitope 3, defines a 16mer core sequence containing one copy of the DPYSh motif, DEDSYERDPYShSQDP. This study performs alanine scanning of this and a related 12mer mimotope, LLDPYAhRAWTK. IgE binding, using a pool of 10 sera and with individual sera, is greatly reduced when alanine is substituted for aspartate at position 8 (D8; p < 0.01), tyrosine at position 10 (Y10; p < 0.01), and hydroxyproline at position 12 (h12; p < 0.001). IgE binding to alanine-substituted peptides of a mimotope containing the DPY_h motif confirm the critical importance of Y (p < 0.01) and h (p < 0.01), but not D. Molecular modeling of the core and mimotope suggests an h-dependent conformational basis for the recognition of these sequences by polyclonal IgE. CONCLUSIONS IgE from pooled sera and individual sera differentially bound amino acids throughout the sequences of Epitope 3 and its mimotope, with Y10 and h12 being most important for all sera. These results are highly significant for designing hypoallergenic forms of Ara h 2.
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Affiliation(s)
- Nicole Canon
- Division of Allergy and Immunology, Kelsey-Seybold Clinic, Houston, TX
| | - Catherine H. Schein
- Institute for Human Infections and Immunity (IHII), The University of Texas Medical Branch, Galveston, TX
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX
| | - Surendra S. Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, TX
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX
| | - Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Michael D. Kulis
- Division of Pediatric Allergy and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Edwin H. Kim
- Division of Pediatric Allergy and Immunology, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Vidya Pathy
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Marina Pozzoli
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Weimin Liu
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO
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Negi SS, Schein CH, Braun W. The updated Structural Database of Allergenic Proteins (SDAP 2.0) provides 3D models for allergens and incorporated bioinformatics tools. THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY. GLOBAL 2023; 2:100162. [PMID: 37781674 PMCID: PMC10509899 DOI: 10.1016/j.jacig.2023.100162] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 07/07/2023] [Accepted: 07/08/2023] [Indexed: 10/03/2023]
Abstract
Background Allergenic proteins can cause IgE-mediated adverse reactions in sensitized individuals. Although the sequences of many allergenic proteins have been identified, bioinformatics data analysis with advanced computational methods and modeling is needed to identify the basis for IgE binding and cross-reactivity. Objective We aim to present the features and use of the updated Structural Database of Allergenic Proteins 2.0 (SDAP 2.0) webserver, a unique, publicly available resource to compare allergens using specially designed computational tools and new high-quality 3-D models for most known allergens. Methods Previously developed and novel software tools for identifying cross-reactive allergens using sequence and structure similarity are implemented in SDAP 2.0. A comprehensive set of high-quality 3-D models of most allergens was generated with the state-of-the-art AlphaFold 2 software. A graphics tool enables the interactive visualization of IgE epitopes on experimentally determined and modeled 3-D structures. Results A user can search for allergens similar to a given input sequence with the FASTA algorithm or the window-based World Health Organization/International Union of Immunological Societies (WHO/IUIS) guidelines on safety concerns of novel food products. Peptides similar to known IgE epitopes can be identified with the property distance tool and conformational epitopes by the Cross-React method. The updated database contains 1657 manually curated sequences including all allergens from the IUIS database, 334 experimentally determined X-ray or NMR structures, and 1565 3-D models. Each allergen/isoallergen is classified according to its protein family. Conclusions SDAP provides access to the steadily increasing information on allergenic structures and epitopes with integrated bioinformatics tools to identify and analyze their similarities. In addition to serving the research and regulatory community, it provides clinicians with tools to identify potential coallergies in a sensitive patient and can help companies to design hypoallergenic foods and immunotherapies.
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Affiliation(s)
- Surendra S. Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Tex
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Catherine H. Schein
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Tex
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Tex
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
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Zhang Y, Che H, Li C, Jin T. Food Allergens of Plant Origin. Foods 2023; 12:foods12112232. [PMID: 37297475 DOI: 10.3390/foods12112232] [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: 04/15/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
This review presents an update on the physical, chemical, and biological properties of food allergens in plant sources, focusing on the few protein families that contribute to multiple food allergens from different species and protein families recently found to contain food allergens. The structures and structural components of the food allergens in the allergen families may provide further directions for discovering new food allergens. Answers as to what makes some food proteins allergens are still elusive. Factors to be considered in mitigating food allergens include the abundance of the protein in a food, the property of short stretches of the sequence of the protein that may constitute linear IgE binding epitopes, the structural properties of the protein, its stability to heat and digestion, the food matrix the protein is in, and the antimicrobial activity to the microbial flora of the human gastrointestinal tract. Additionally, recent data suggest that widely used techniques for mapping linear IgE binding epitopes need to be improved by incorporating positive controls, and methodologies for mapping conformational IgE binding epitopes need to be developed.
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Affiliation(s)
- Yuzhu Zhang
- US Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, CA 94710, USA
| | - Huilian Che
- Key Laboratory of Precision Nutrition and Food Quality, Key Laboratory of Functional Dairy, Ministry of Education, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Caiming Li
- US Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, CA 94710, USA
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi 214122, China
| | - Tengchuan Jin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230001, China
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Zhang Y, Song M, Xu J, Li X, Yang A, Tong P, Wu Z, Chen H. IgE Recognition and Structural Analysis of Disulfide Bond Rearrangement and Chemical Modifications in Allergen Aggregations in Roasted Peanuts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37256970 DOI: 10.1021/acs.jafc.3c01482] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Given that roasting changes the structure and allergenicity of peanut allergens, the structural information of peanut allergens must be expounded to explain the alteration in their allergenicity. This work focused on allergen aggregations (AAs) in roasted peanuts. IgE recognition capability was assessed via western blot analysis. The disulfide bond (DB) rearrangement and chemical modification in AAs were identified by combining mass spectroscopy and software tools, and structural changes induced by cross-links were displayed by molecular dynamics and PyMOL software. Results showed that AAs were strongly recognized by IgE and cross-linked mainly by DBs. The types of DB rearrangement in AAs included interprotein (98 peptide pairs), intraprotein (22 peptide pairs), and loop-linked (6 peptides) DBs. Among allergens, Ara h 2 and Ara h 6 presented the most cysteine residues to cross-linkf with others or themselves. DB rearrangement involved IgE epitopes and induced structural changes. Ara h 1 and Ara h 3 were predominantly chemically modified. Moreover, chemical modification altered the local structures of proteins, which may change the allergenic potential of allergens.
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Affiliation(s)
- Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Min Song
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Jiyuan Xu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - 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
| | - 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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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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Zhang Y, Bhardwaj SR, Lyu SC, Chinthrajah S, Nadeau KC, Li C. Expression, purification, characterization, and patient IgE reactivity of new macadamia nut iso-allergen. Protein Expr Purif 2023; 203:106211. [PMID: 36462715 DOI: 10.1016/j.pep.2022.106211] [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: 09/30/2022] [Revised: 11/24/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022]
Abstract
Structural and functional information about food allergens is essential for understanding the allergenicity of food proteins. All allergens belong to a small number of protein families. Various allergens from different families have been successfully produced recombinantly in E. coli for their characterization and applications in allergy diagnosis and treatment. However, recombinant hexameric 11S seed storage protein has not been reported, although numerous 11S legumins are known to be food allergens, including the recently identified macadamia nut allergen Mac i 2. Here we report the production of a macadamia nut legumin by expressing it in E. coli with a substrate site of HRV 3C protease and cleaving the purified protein with HRV 3C protease. The protease divided the protein into two chains and left a native terminus for the C-terminal chain, resulting in a recombinant hexameric 11S allergen for the first time after the residues upstream to the cleavage site flipped out of the way of the trimer-trimer interaction. The 11S allergens are known to have multiple isoforms in many species. The present study removed an obstacle in obtaining homogeneous allergens needed for studying allergens and mitigating allergenicity. Immunoreactivity of the protein with serum IgE confirmed it to be a new isoform of Mac i 2.
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Affiliation(s)
- Yuzhu Zhang
- US Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, CA, 94710, USA.
| | - Shilpa R Bhardwaj
- US Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, CA, 94710, USA
| | - Shu-Chen Lyu
- Division of Pediatric Immunology, Allergy, and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, 269 Campus Dr, Stanford, CA, 94305, USA
| | - Sharon Chinthrajah
- Division of Pediatric Immunology, Allergy, and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, 269 Campus Dr, Stanford, CA, 94305, USA
| | - Kari C Nadeau
- Division of Pediatric Immunology, Allergy, and Rheumatology, Department of Pediatrics, Stanford University School of Medicine, 269 Campus Dr, Stanford, CA, 94305, USA
| | - Caiming Li
- School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
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Impacts of Sourdough Technology on the Availability of Celiac Peptides from Wheat α- and γ-Gliadins: In Silico Approach. ALLERGIES 2023. [DOI: 10.3390/allergies3010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Celiac peptide-generating α- and γ-gliadins consist of a disordered N-terminal domain extended by an α-helical-folded C-terminal domain. Celiac peptides, primarily located along the disordered part of α- and γ-gliadin molecules, are nicely exposed and directly accessible to proteolytic enzymes occurring in the gastric (pepsin) and intestinal (trypsin, chymotrypsin) fluids. More than half of the potential celiac peptides identified so far in gliadins exhibit cleavage sites for pepsin. However, celiac peptides proteolytically truncated by one or two amino acid residues could apparently retain some activity toward HLA-DQ2 and HLA-DQ8 receptors in docking experiments. Together with the uncleaved peptides, these still active partially degraded CD peptides account for the incapacity of the digestion process to inactivate CD peptides from gluten proteins. In contrast, sourdough fermentation processes involve other proteolytic enzymes susceptible to the deep degradation of celiac peptides. In particular, sourdough supplemented by fungal prolyl endoproteases enhances the degrading capacities of the sourdough fermentation process toward celiac peptides. Nevertheless, since tiny amounts of celiac peptides sufficient to trigger deleterious effects on CD people can persist in sourdough-treated bread and food products, it is advisable to avoid consumption of sourdough-treated food products for people suffering from celiac disease. As an alternative, applying the supplemented sourdough process to genetically modified low gluten or celiac-safe wheat lines should result in food products that are safer for susceptible and CD people.
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LaHood NA, Min J, Keswani T, Richardson CM, Amoako K, Zhou J, Marini-Rapoport O, Bernard H, Hazebrouck S, Shreffler WG, Love JC, Pomes A, Pedersen LC, Mueller GA, Patil SU. Immunotherapy-induced neutralizing antibodies disrupt allergen binding and sustain allergen tolerance in peanut allergy. J Clin Invest 2023; 133:e164501. [PMID: 36647835 PMCID: PMC9843057 DOI: 10.1172/jci164501] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 11/15/2022] [Indexed: 01/18/2023] Open
Abstract
In IgE-mediated food allergies, exposure to the allergen activates systemic allergic responses. Oral immunotherapy (OIT) treats food allergies through incremental increases in oral allergen exposure. However, OIT only induces sustained clinical tolerance and decreased basophil sensitivity in a subset of individuals despite increases in circulating allergen-specific IgG in all treated individuals. Therefore, we examined the allergen-specific antibodies from 2 OIT cohorts of patients with sustained and transient responses. Here, we compared antibodies from individuals with sustained or transient responses and discovered specific tolerance-associated conformational epitopes of the immunodominant allergen Ara h 2 recognized by neutralizing antibodies. First, we identified what we believe to be previously unknown conformational, intrahelical epitopes using x-ray crystallography with recombinant antibodies. We then identified epitopes only recognized in sustained tolerance. Finally, antibodies recognizing tolerance-associated epitopes effectively neutralized allergen to suppress IgE-mediated effector cell activation. Our results demonstrate the molecular basis of antibody-mediated protection in IgE-mediated food allergy, by defining how these antibodies disrupt IgE-allergen interactions to prevent allergic reactions. Our approach to studying the structural and functional basis for neutralizing antibodies demonstrates the clinical relevance of specific antibody clones in antibody-mediated tolerance. We anticipate that our findings will form the foundation for treatments of peanut allergy using neutralizing antibodies and hypoallergens.
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Affiliation(s)
- Nicole A. LaHood
- Food Allergy Center and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jungki Min
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Tarun Keswani
- Food Allergy Center and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Kwasi Amoako
- Food Allergy Center and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jingjia Zhou
- Food Allergy Center and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Hervé Bernard
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), Gif-sur-Yvette, France
| | - Stéphane Hazebrouck
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), Gif-sur-Yvette, France
| | - Wayne G. Shreffler
- Food Allergy Center and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - J. Christopher Love
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | | | - Lars C. Pedersen
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Geoffrey A. Mueller
- National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Sarita U. Patil
- Food Allergy Center and Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
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12
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Mameri H, Gaudin JC, Lollier V, Tranquet O, Brossard C, Pietri M, Marion D, Codreanu-Morel F, Beaudouin E, Wien F, Gohon Y, Briozzo P, Denery-Papini S. Critical structural elements for the antigenicity of wheat allergen LTP1 (Tri a 14) revealed by site-directed mutagenesis. Sci Rep 2022; 12:12253. [PMID: 35851276 PMCID: PMC9293932 DOI: 10.1038/s41598-022-15811-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/29/2022] [Indexed: 11/09/2022] Open
Abstract
Lipid transfer proteins (LTPs) were identified as allergens in a large variety of pollens and foods, including cereals. LTPs belong to the prolamin superfamily and display an α-helical fold, with a bundle of four α-helices held together by four disulfide bonds. Wheat LTP1 is involved in allergic reactions to food. To identify critical structural elements of antibody binding to wheat LTP1, we used site-directed mutagenesis on wheat recombinant LTP1 to target: (i) sequence conservation and/or structure flexibility or (ii) each disulfide bond. We evaluated the modifications induced by these mutations on LTP1 secondary structure by synchrotron radiation circular dichroism and on its antigenicity with patient's sera and with mouse monoclonal antibodies. Disruption of the C28-C73 disulfide bond significantly affected IgE-binding and caused protein denaturation, while removing C13-C27 bond decreased LTP1 antigenicity and slightly modified LTP1 overall folding. In addition, we showed Lys72 to be a key residue; the K72A mutation did not affect global folding but modified the local 3D structure of LTP1 and strongly reduced IgE-binding. This work revealed a cluster of residues (C13, C27, C28, C73 and K72), four of which embedded in disulfide bonds, which play a critical role in LTP1 antigenicity.
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Affiliation(s)
- Hamza Mameri
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France. .,UMR 1208 IATE, Univ Montpellier, INRAE, L'Institut-Agro Montpellier, 34060, Montpellier, France.
| | - Jean-Charles Gaudin
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France.,INRAE, UMR 0588 Biologie intégrée pour la valorisation de la diversité des arbres et de la forêt (BIOFORA), 45075, Orléans, France
| | - Virginie Lollier
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France.,INRAE, UR BIA, 44316, Nantes, France.,INRAE, PROBE Research Infrastructure, BIBS Facility, 44316, Nantes, France
| | - Olivier Tranquet
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France.,INRAE UMR 1163 Biodiversité et Biotechnologie Fongiques (BBF), 13288, Marseille, France
| | - Chantal Brossard
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France
| | - Manon Pietri
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France.,Institut de Cancérologie de l'Ouest, Centre René Gauducheau, 44805, Saint Herblain Cedex, France
| | - Didier Marion
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France
| | - Fanny Codreanu-Morel
- CHU Luxembourg, Centre Hospitalier de Luxembourg, Kanner Klinik, 1210, Luxembourg, Luxembourg
| | - Etienne Beaudouin
- Service d'Allergologie, Hôpital de Mercy, CHR Metz, 57000, Metz, France
| | - Frank Wien
- Synchrotron Soleil, Saint-Aubin, 91192, Gif-sur-Yvette, France
| | - Yann Gohon
- INRAE, UMR 1318 Institut Jean-Pierre Bourgin, 78026, Versailles, France
| | - Pierre Briozzo
- INRAE, UMR 1318 Institut Jean-Pierre Bourgin, 78026, Versailles, France
| | - Sandra Denery-Papini
- INRAE, UR 1268 Biopolymères Interactions Assemblages (BIA), 44316, Nantes, France.
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13
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Hazebrouck S, Patil SU, Guillon B, Lahood N, Dreskin SC, Adel-Patient K, Bernard H. Immunodominant conformational and linear IgE epitopes lie in a single segment of Ara h 2. J Allergy Clin Immunol 2022; 150:131-139. [PMID: 35150723 PMCID: PMC10440805 DOI: 10.1016/j.jaci.2021.12.796] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 12/16/2021] [Accepted: 12/27/2021] [Indexed: 11/21/2022]
Abstract
BACKGROUND Contribution of conformational epitopes to the IgE reactivity of peanut allergens Ara h 2 and Ara h 6 is at least as important as that of the linear epitopes. However, little is known about these conformational IgE-binding epitopes. OBJECTIVE We investigated the distribution of conformational epitopes on chimeric 2S-albumins. METHODS Recombinant chimeras were generated by exchanging structural segments between Ara h 2 and Ara h 6. Well-refolded chimeras, as verified by circular dichroism analysis, were then used to determine the epitope specificity of mAbs by performing competitive inhibition of IgG binding. Furthermore, we delineated the contribution of each segment to the overall IgE reactivity of both 2S-albumins by measuring the chimeras' IgE-binding capacity with sera from 21 patients allergic to peanut. We finally assessed chimeras' capacity to trigger mast cell degranulation. RESULTS Configuration of the conformational epitopes was preserved in the chimeras. Mouse IgG mAbs, raised against natural Ara h 6, and polyclonal human IgE antibodies recognized different conformational epitopes distributed all along Ara h 6. In contrast, we identified human IgG mAbs specific to different Ara h 2 linear or conformational epitopes located in all segments except the C-terminal one. The major conformational IgE-binding epitope of Ara h 2 was located in a segment located between residues 33 and 81 that also contains the major linear hydroxyproline-containing epitope. Accordingly, this segment is critical for the capacity of Ara h 2 to induce mast cell degranulation. CONCLUSIONS Chimeric 2S-albumins provide new insights on the conformational IgE-binding epitopes of Ara h 2 and Ara h 6. Proximity of the immunodominant linear and conformational IgE-binding epitopes probably contributes to the high allergenic potency of Ara h 2.
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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.
| | - Sarita U Patil
- Department of Medicine, Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, the Food Allergy Center, Massachusetts General Hospital for Children, and Harvard Medical School, Boston, Mass
| | - Blanche Guillon
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
| | - Nicole Lahood
- Department of Medicine, Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, the Food Allergy Center, Massachusetts General Hospital for Children, and Harvard Medical School, Boston, Mass
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado-Denver, Aurora, Colo
| | - Karine Adel-Patient
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
| | - Hervé Bernard
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
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14
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Blum LA, Ahrens B, Klimek L, Beyer K, Gerstlauer M, Hamelmann E, Lange L, Nemat K, Vogelberg C, Blümchen K. White Paper Erdnussallergie - Teil 2: Diagnostik der Erdnussallergie unter besonderer Berücksichtigung der molekularen Komponentendiagnostik. ALLERGO JOURNAL 2021. [DOI: 10.1007/s15007-021-4931-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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15
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Cabanos C, Matsuoka Y, Maruyama N. Soybean proteins/peptides: A review on their importance, biosynthesis, vacuolar sorting, and accumulation in seeds. Peptides 2021; 143:170598. [PMID: 34153351 DOI: 10.1016/j.peptides.2021.170598] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 05/25/2021] [Accepted: 06/14/2021] [Indexed: 12/20/2022]
Abstract
Soybean is one of the most important sources of plant protein and is known for its wide range of agricultural, food, and industrial applications as well as health benefits. Interest in soybean proteins has been steadily growing as progressively more applications and benefits are discovered. This review article is focused on the major seed storage proteins of soybean, their three-dimensional structures, their nutritional importance and bioactive peptides, cellular synthesis, and accumulation in seeds. This will also summarize past efforts in the recombinant production of foreign proteins or bioactive peptides in soybean seed.
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Affiliation(s)
- Cerrone Cabanos
- Laboratory of Food Quality Design and Development, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Yuki Matsuoka
- Laboratory of Food Quality Design and Development, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Nobuyuki Maruyama
- Laboratory of Food Quality Design and Development, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, 611-0011, Japan.
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16
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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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17
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Dreskin SC, Koppelman SJ, Andorf S, Nadeau KC, Kalra A, Braun W, Negi SS, Chen X, Schein CH. The importance of the 2S albumins for allergenicity and cross-reactivity of peanuts, tree nuts, and sesame seeds. J Allergy Clin Immunol 2021; 147:1154-1163. [PMID: 33217410 PMCID: PMC8035160 DOI: 10.1016/j.jaci.2020.11.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022]
Abstract
Allergies to peanuts, tree nuts, and sesame seeds are among the most important food-related causes of anaphylaxis. Important clinical questions include: Why is there a variable occurrence of coallergy among these foods and Is this immunologically mediated? The clinical and immunologic data summarized here suggest an immunologic basis for these coallergies that is based on similarities among the 2S albumins. Data from component resolved diagnostics have highlighted the relationship between IgE binding to these allergens and the presence of IgE-mediated food allergy. Furthermore, in vitro and in vivo experiments provide strong evidence that the 2S albumins are the most important allergens in peanuts for inducing an allergic effector response. Although the 2S albumins are diverse, they have a common disulfide-linked core with similar physicochemical properties that make them prime candidates to explain much of the observed coallergy among peanuts, tree nuts, and sesame seeds. The well-established frequency of cashew and pistachio nut coallergy (64%-100%) highlights how the structural similarities among their 2S albumins may account for observed clinical cross-reactivity. A complete understanding of the physicochemical properties of the 2S albumins in peanuts, tree nuts, and sesame seeds will enhance our ability to diagnose, treat, and ultimately prevent these allergies.
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Affiliation(s)
- Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo.
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Neb
| | - Sandra Andorf
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Division of Allergy and Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio; Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Kari C Nadeau
- Sean N. Parker Center for Allergy and Asthma Research, Stanford University School of Medicine, Stanford, Calif
| | - Anjeli Kalra
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch, Galveston, Tex; Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex
| | - Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Catherine H Schein
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, Tex; Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Tex.
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18
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IgE-Binding Epitopes of Pis v 1, Pis v 2 and Pis v 3, the Pistachio (Pistacia vera) Seed Allergens. ALLERGIES 2021. [DOI: 10.3390/allergies1010006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Sequential IgE-binding epitopes were identified on the molecular surface of the Pis v 1 (2S albumin), Pis v 2 (11S globulin/legumin) and Pis v 3 (7S globulin/vicilin)—major allergens from pistachio (Pistacia vera) seeds—using the Spot technique. They essentially consist of hydrophilic and electropositively charged residues well exposed on the surface of the allergens. Most of the epitopic regions identified on Pis v 1 and Pis v 3 do not coincide with the putative N-glycosylation sites and thus are not considered as glycotopes. Surface analysis of these epitopic regions indicates a high degree of conformational similarity with the previously identified epitopic regions of the corresponding allergens Ana o 1 (vicilin), Ana o 2 (legumin) and Ana o 3 (2S albumin) from the cashew (Anacardium occidentale) nut. These results offer a molecular basis for the IgE-binding cross-reactivity often observed between pistachio and cashew nut. They support the recommendation for prescribing pistachio avoidance in cashew allergic patients. Other conformational similarities were identified with the corresponding allergens Ses i 1 (2S albumin), Ses i 3 (vicilin) and Ses i 6 (legumin) from sesame (Sesamum indicum), and Jug r 1 (2S albumin), Jug r 2 (vicilin) and Jug r 4 (legumin) from walnut (Juglans regia). Conversely, conformation of most of the epitopic regions of the pistachio allergens often differs from that of epitopes occurring on the molecular surface of the corresponding Ara h 1 (vicilin), Ara h 2 (2S albumin) and Ara h 3 (legumin) allergens from peanut (Arachis hypogaea).
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19
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Santos AF, Barbosa‐Morais NL, Hurlburt BK, Ramaswamy S, Hemmings O, Kwok M, O’Rourke C, Bahnson HT, Cheng H, James L, Gould HJ, Sutton BJ, Maleki SJ, Lack G. IgE to epitopes of Ara h 2 enhance the diagnostic accuracy of Ara h 2-specific IgE. Allergy 2020; 75:2309-2318. [PMID: 32248566 DOI: 10.1111/all.14301] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Understanding the discrepancy between IgE sensitization and allergic reactions to peanut could facilitate diagnosis and lead to novel means of treating peanut allergy. OBJECTIVE To identify differences in IgE and IgG4 binding to peanut peptides between peanut-allergic (PA) and peanut-sensitized but tolerant (PS) children. METHODS PA (n = 56), PS (n = 42) and nonsensitized nonallergic (NA, n = 10) patients were studied. Synthetic overlapping 15-mer peptides of peanut allergens (Ara h 1-11) were spotted onto microarray slides, and patients' samples were tested for IgE and IgG4 binding using immunofluorescence. IgE and IgG4 levels to selected peptides were quantified using ImmunoCAP. Diagnostic model comparisons were performed using likelihood-ratio tests between each specified nominal logistic regression models. RESULTS Seven peptides on Ara h 1, Ara h 2, and Ara h 3 were bound more by IgE of PA compared to PS patients on the microarray. IgE binding to one peptide on Ara h 5 and IgG4 binding to one Ara h 9 peptide were greater in PS than in PA patients. Using ImmunoCAP, IgE to the Ara h 2 peptides enhanced the diagnostic accuracy of Ara h 2-specific IgE. Ratios of IgG4/IgE to 4 out of the 7 peptides were higher in PS than in PA subjects. CONCLUSIONS Ara h 2 peptide-specific IgE added diagnostic value to Ara h 2-specific IgE. Ability of peptide-specific IgG4 to surmount their IgE counterpart seems to be important in established peanut tolerance.
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Affiliation(s)
- 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
- Children’s Allergy ServiceEvelina London Children's Hospital, Guy’s and St Thomas’ Hospital London UK
- Asthma UK Centre in Allergic Mechanisms of Asthma London UK
| | - Nuno L. Barbosa‐Morais
- Faculdade de Medicina Instituto de Medicina Molecular João Lobo Antunes Universidade de Lisboa Lisbon Portugal
| | - Barry K. Hurlburt
- US Department of Agriculture Southern Regional Research Center New Orleans LA USA
| | - Sneha Ramaswamy
- Asthma UK Centre in Allergic Mechanisms of Asthma London UK
- Randall Centre for Cell & Molecular Biophysics King’s College London London UK
| | - 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
- 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
- Asthma UK Centre in Allergic Mechanisms of Asthma London UK
| | | | | | - Hsiaopo Cheng
- US Department of Agriculture Southern Regional Research Center New Orleans LA USA
| | - Louisa James
- Blizard Institute Queen Mary University of London London UK
| | - Hannah J. Gould
- Asthma UK Centre in Allergic Mechanisms of Asthma London UK
- Randall Centre for Cell & Molecular Biophysics King’s College London London UK
| | - Brian J. Sutton
- Asthma UK Centre in Allergic Mechanisms of Asthma London UK
- Randall Centre for Cell & Molecular Biophysics King’s College London London UK
| | - Soheila J. Maleki
- US Department of Agriculture Southern Regional Research Center New Orleans LA USA
| | - Gideon Lack
- 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
- Children’s Allergy ServiceEvelina London Children's Hospital, Guy’s and St Thomas’ Hospital London UK
- Asthma UK Centre in Allergic Mechanisms of Asthma London UK
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20
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Larsen JM, Bang-Berthelsen CH, Qvortrup K, Sancho AI, Hansen AH, Andersen KIH, Thacker SSN, Eiwegger T, Upton J, Bøgh KL. Production of allergen-specific immunotherapeutic agents for the treatment of food allergy. Crit Rev Biotechnol 2020; 40:881-894. [PMID: 32515236 DOI: 10.1080/07388551.2020.1772194] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Allergen-specific immunotherapy (IT) is emerging as a viable avenue for the treatment of food allergies. Clinical trials currently investigate raw or slightly processed foods as therapeutic agents, as trials using food-grade agents can be performed without the strict regulations to which conventional drugs are subjected. However, this limits the ability of standardization and may affect clinical trial outcomes and reproducibility. Herein, we provide an overview of methods used in the production of immunotherapeutic agents for the treatment of food allergies, including processed foods, allergen extracts, recombinant allergens, and synthetic peptides, as well as the physical and chemical processes for the reduction of protein allergenicity. Commercial interests currently favor producing standardized drug-grade allergen extracts for therapeutic use, and clinical trials are ongoing. In the near future, recombinant production could replace purification strategies since it allows the manufacturing of pure, native allergens or sequence-modified allergens with reduced allergenicity. A recurring issue within this field is the inadequate reporting of production procedures, quality control, product physicochemical characteristics, allergenicity, and immunological properties. This information is of vital importance in assessing therapeutic standardization and clinical safety profile, which are central parameters for the development of future therapeutic agents.
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Affiliation(s)
- Jeppe Madura Larsen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | | | - Katrine Qvortrup
- Department of Chemistry, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ana Isabel Sancho
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | | | | | | | - Thomas Eiwegger
- Division of Immunology and Allergy, Food Allergy and Anaphylaxis Program, The Department of Pediatrics, The Hospital for Sick Children, Toronto, Canada.,Research Institute, The Hospital for Sick Children, Translational Medicine Program, Toronto, Canada.,Department of Immunology, The University of Toronto, Toronto, Canada
| | - Julia Upton
- Division of Immunology and Allergy, Food Allergy and Anaphylaxis Program, The Department of Pediatrics, The Hospital for Sick Children, Toronto, Canada
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21
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Nesbit JB, Schein CH, Braun BA, Gipson SAY, Cheng H, Hurlburt BK, Maleki SJ. Epitopes with similar physicochemical properties contribute to cross reactivity between peanut and tree nuts. Mol Immunol 2020; 122:223-231. [PMID: 32442779 DOI: 10.1016/j.molimm.2020.03.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/11/2020] [Accepted: 03/26/2020] [Indexed: 12/28/2022]
Abstract
Many individuals with peanut (PN) allergy have severe reactions to tree nuts (TN) such as walnuts or cashews. Although allergenic proteins in TN and PN have overall low identity, they share discrete sequences similar in physicochemical properties (PCP) to known IgE epitopes. Here, PCP-consensus peptides (cp, 13 aa and 31 aa) were identified from an alignment of epitope rich regions of walnut vicilin, Jug r 2, leader sequence (J2LS) and cross-reactive epitopes in the 2S albumins of peanut and synthesized. A peptide similarity search in the Structural Database of Allergenic Proteins (SDAP) revealed a network of peptides similar (low property distance, PD) to the 13 aa cp (13cp) in many different plant allergens. Peptides similar to the 13cp in PN and TN allergens bound IgE from sera of patients allergic to PN and TN in peptide microarray analysis. The 13cp was used to produce a rabbit consensus peptide antibody (cpAB) that detected proteins containing repeats similar to the 13cp in western blots of various nut extracts, in which reactive proteins were identified by mass spectrometry. The cpAB bound more specifically to allergens and nut extracts containing multiple repeats similar to the 13 cp, such as almond (Pru du 6), peanut (Ara h 2) and walnut (Jug r 2). IgE binding to various nut extracts is inhibited by recombinant J2LS sequence and synthetic 31cp. Thus, several repeated sequences similar to the 13cp are bound by IgE. Multiple similar repeats in several allergens could account for reaction severity and clinically relevant cross-reactivity to PN and TN. These findings may help improve detection, diagnostic, and therapeutic tools.
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Affiliation(s)
- Jacqueline B Nesbit
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Catherine H Schein
- Department of Biochemistry and Molecular Biology, Institute for Human Infection and Immunity, University of Texas Medical Branch at Galveston (UTMB), TX, United States.
| | - Benjamin A Braun
- Department of Computer Science, Stanford University, United States
| | - Stephen A Y Gipson
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Hsiaopo Cheng
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Barry K Hurlburt
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Soheila J Maleki
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States.
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Ren L, Wu Z, Zhang Y, Li K, Yuan J, Li X, Yang A, Tong P, Chen H. Polyphenol-oxidase-catalyzed cross-linking of Ara h 2: reaction sites and effect on structure and allergenicity. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:308-314. [PMID: 31525267 DOI: 10.1002/jsfa.10040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 08/25/2019] [Accepted: 09/11/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Peanut is among the most common of food allergies, and one of its allergens is Ara h 2. A previous study revealed that this allergen was recognized by serum immunoglobulin E (IgE) in over 90% of a peanut-allergic patient population. Enzymatic cross-linking is a popular processing method used to tailor food functionality, such as antigenicity. RESULT The cross-linking reactions of Ara h 2 were catalyzed by polyphenol oxidase (PPO), and the relevant reaction sites were identified using mass spectrometry and StavroX software. Two pairs of intramolecular cross-linking peptides and two intermolecular cross-linking peptides were found. Intramolecular cross-linking was speculated to occur between ARG131 (amino acids 116-131) and TYR65 (amino acids 63-80) and between TYR60 (amino acids 56-62) and ARG92 (amino acids 92-102); the intermolecular cross-linking sites were ARG31 with TYR84 or TYR89 and TYR65 or TYR72 with ARG92 or ARG102 . Three out of four cross-linking peptides were found in α-helices, and destruction of this secondary structure resulted in a loose tertiary structure. Although seven linear allergen epitopes were involved in cross-linking, the IgE binding capacity of protein changed slightly, while its sensitization potential decreased in mouse model. CONCLUSION Exploring the structural change of Ara h 2 after cross-linking is beneficial in further understanding the influence of structure on sensitization. This result indicated the future possibility of precision processing on structure of proteins to improve their properties. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Linmei Ren
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Environment and Chemical Engineering, Nanchang University, Nanchang, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Food Science and Technology, Nanchang University, Nanchang, China
| | - Kun Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Hubei Provincial Key Lab for Quality and Safety of Traditional Chinese Medicine Health Food Jing Brand Bio-medicine Co Ltd, Huangshi, China
| | - Juanli Yuan
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- School of Pharmaceutical Science, Nanchang University, Nanchang, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, China
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Hilu KW, Friend SA, Vallanadu V, Brown AM, Hollingsworth LR, Bevan DR. Molecular evolution of genes encoding allergen proteins in the peanuts genus Arachis: Structural and functional implications. PLoS One 2019; 14:e0222440. [PMID: 31675366 PMCID: PMC6824556 DOI: 10.1371/journal.pone.0222440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/29/2019] [Indexed: 12/14/2022] Open
Abstract
Food allergies are severe immune responses to plant and animal products mediated by immunoglobulin E (IgE). Peanuts (Arachis hypogaea L.) are among the top 15 crops that feed the world. However, peanuts is among the "big eight food allergens", and allergies induced by peanuts are a significant public health problem and a life-threatening concern. Targeted mutation studies in peanuts demonstrate that single residue alterations in these allergen proteins could result in substantial reduction in allergenicity. Knowledge of peanut allergen proteins is confined to the allotetraploid crop and its two progenitors. We explored frequencies and positions of natural mutations in the hyperallergenic homologues Ara h 2 and Ara h 6 in newly generated sequences for 24 Arachis wild species and the crop species, assessed potential mutational impact on allergenicity using immunoblots and structural modeling, and evaluated whether these mutations follow evolutionary trends. We uncovered a wealth of natural mutations, both substitutions and gaps, including the elimination of immunodominant epitopes in some species. These molecular alterations appear to be associated with substantial reductions in allergenicity. The study demonstrated that Ara h 2 and Ara h 6 follow contrasting modes of natural selection and opposing mutational patterns, particularly in epitope regions. Phylogenetic analysis revealed a progressive trend towards immunodominant epitope evolution in Ara h 2. The findings provide valuable insight into the interactions among mutations, protein structure and immune system response, thus presenting a valuable platform for future manipulation of allergens to minimize, treat or eliminate allergenicity. The study strongly encourages exploration of genepools of economically important plants in allergenicity research.
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Affiliation(s)
- Khidir W. Hilu
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America
| | - Sheena A. Friend
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America
| | - Viruthika Vallanadu
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States of America
| | - Anne M. Brown
- Research and Informatics, Virginia Tech, Blacksburg, VA, United States of America
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, United States of America
| | | | - David R. Bevan
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, United States of America
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25
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Tscheppe A, Palmberger D, van Rijt L, Kalic T, Mayr V, Palladino C, Kitzmüller C, Hemmer W, Hafner C, Bublin M, van Ree R, Grabherr R, Radauer C, Breiteneder H. Development of a novel Ara h 2 hypoallergen with no IgE binding or anaphylactogenic activity. J Allergy Clin Immunol 2019; 145:229-238. [PMID: 31525384 PMCID: PMC7100897 DOI: 10.1016/j.jaci.2019.08.036] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 07/31/2019] [Accepted: 08/16/2019] [Indexed: 02/03/2023]
Abstract
Background To date, no safe allergen-specific immunotherapy for patients with peanut allergy is available. Previous trials were associated with severe side effects. Objective We sought to determine the relative importance of conformational and linear IgE-binding epitopes of the major peanut allergen Ara h 2 and to produce a hypoallergenic variant with abolished anaphylactogenic activity. Methods Wild-type Ara h 2 and a mutant lacking the loops containing linear IgE epitopes were produced in insect cells. Conformational IgE epitopes were removed by unfolding these proteins through reduction and alkylation. IgE binding was tested by means of ELISA with sera from 48 Ara h 2–sensitized patients with peanut allergy. Basophil activation and T-cell proliferation were tested with blood samples from selected patients. Anaphylactogenic potency was tested by using intraperitoneal challenge of mice sensitized intragastrically to peanut extract. Results Patients’ IgE recognized conformational and linear epitopes in a patient-specific manner. The unfolded mutant lacking both types of epitopes displayed significantly lower IgE binding (median ELISA OD, 0.03; interquartile range, 0.01-0.06) than natural Ara h 2 (median ELISA OD, 0.99; interquartile range, 0.90-1.03; P < .01). Basophil activation by unfolded mutant Ara h 2 was low (median area under the curve, 72 vs 138 for native wild-type Ara h 2; P < .05), but its ability to induce T-cell proliferation was retained. Unfolded mutants without conformational epitopes did not induce anaphylaxis in peanut-sensitized mice. Conclusions By removing conformational and linear IgE epitopes, a hypoallergenic Ara h 2 mutant with abolished IgE binding and anaphylactogenic potency but retained T-cell activation was generated.
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Affiliation(s)
- Angelika Tscheppe
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Dieter Palmberger
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Leonie van Rijt
- Department of Experimental Immunology, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Tanja Kalic
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Vanessa Mayr
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Chiara Palladino
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Claudia Kitzmüller
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | | | - Christine Hafner
- Department of Dermatology, University Hospital St Pölten, Karl Landsteiner University of Health Sciences, St Pölten, and the Karl Landsteiner Institute for Dermatological Research, St Pölten, Austria
| | - Merima Bublin
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Ronald van Ree
- Department of Experimental Immunology, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Otorhinolaryngology, Amsterdam UMC, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Reingard Grabherr
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Christian Radauer
- 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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A cashew specific monoclonal antibody recognizing the small subunit of Ana o 3. Toxicol Rep 2019; 6:736-744. [PMID: 31388501 PMCID: PMC6676374 DOI: 10.1016/j.toxrep.2019.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 06/13/2019] [Accepted: 06/27/2019] [Indexed: 01/07/2023] Open
Abstract
Food allergies represent a substantial medical liability and preventing accidental exposure to food allergens requires constant attention. Allergic reaction to cashew nuts is frequently serious, and the small 2S albumin, Ana o 3, is an immuno-dominant cashew allergen. Ana o 3 is composed of five alpha helices, contains 2 subunits linked by cysteine disulfide bonds, and remains soluble even after extensive heating of cashew nuts. The stability and solubility properties of Ana o 3 make it an excellent target for diagnostic and detection methods and tools. In this work, a monoclonal antibody, designated 2H5, aimed at amino acids 39–54 within helices I and II of the small subunit of Ana o 3 was developed that recognizes both recombinant and native Ana o 3 and is cashew specific in ELISA experiments. The KD against the targeted amino-acid sequence was found to be approximately 7.0 × 10−6 mg/ml (3.3 nM), while the KD against the native protein was found to be approximately 1.2 × 10-3 mg/ml (92 nM). The 2H5 monoclonal anti-Ana o 3 antibody can distinguish between native and recombinant proteins and represents a useful reagent for the study of antibody cashew-allergen interactions and may enable the development of cashew-specific diagnostic tools that can be used to prevent accidental cashew allergen exposures.
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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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28
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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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29
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Designer covalent heterobivalent inhibitors prevent IgE-dependent responses to peanut allergen. Proc Natl Acad Sci U S A 2019; 116:8966-8974. [PMID: 30962381 PMCID: PMC6500160 DOI: 10.1073/pnas.1820417116] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Allergies are a result of allergen proteins cross-linking allergen-specific IgE (sIgE) on the surface of mast cells and basophils. The diversity and complexity of allergen epitopes, and high-affinity of the sIgE-allergen interaction have impaired the development of allergen-specific inhibitors of allergic responses. This study presents a design of food allergen-specific sIgE inhibitors named covalent heterobivalent inhibitors (cHBIs) that selectively form covalent bonds to only sIgEs, thereby permanently inhibiting them. Using screening reagents termed nanoallergens, we identified two immunodominant epitopes in peanuts that were common in a population of 16 allergic patients. Two cHBIs designed to inhibit only these two epitopes completely abrogated the allergic response in 14 of the 16 patients in an in vitro assay and inhibited basophil activation in an allergic patient ex vivo analysis. The efficacy of the cHBI design has valuable clinical implications for many allergen-specific responses and more broadly for any antibody-based disease.
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30
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Jappe U, Schwager C, Schromm AB, González Roldán N, Stein K, Heine H, Duda KA. Lipophilic Allergens, Different Modes of Allergen-Lipid Interaction and Their Impact on Asthma and Allergy. Front Immunol 2019; 10:122. [PMID: 30837983 PMCID: PMC6382701 DOI: 10.3389/fimmu.2019.00122] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 01/15/2019] [Indexed: 12/12/2022] Open
Abstract
Molecular allergology research has provided valuable information on the structure and function of single allergenic molecules. There are several allergens in food and inhalant allergen sources that are able to interact with lipid ligands via different structural features: hydrophobic pockets, hydrophobic cavities, or specialized domains. For only a few of these allergens information on their associated ligands is already available. Several of the allergens are clinically relevant, so that it is highly probable that the individual structural features with which they interact with lipids have a direct effect on their allergenic potential, and thus on allergy development. There is some evidence for a protective effect of lipids delaying the enzymatic digestion of the peanut (Arachis hypogaea) allergen Ara h 8 (hydrophobic pocket), probably allowing this molecule to get to the intestinal immune system intact (sensitization). Oleosins from different food allergen sources are part of lipid storage organelles and potential marker allergens for the severity of the allergic reaction. House dust mite (HDM), is more often associated with allergic asthma than other sources of inhalant allergens. In particular, lipid-associated allergens from Dermatophagoides pteronyssinus which are Der p 2, Der p 5, Der p 7, Der p 13, Der p 14, and Der p 21 have been reported to be associated with severe allergic reactions and respiratory symptoms such as asthma. The exact mechanism of interaction of these allergens with lipids still has to be elucidated. Apart from single allergens glycolipids have been shown to directly induce allergic inflammation. Several-in parts conflicting-data exist on the lipid (and allergen) and toll-like receptor interactions. For only few single allergens mechanistic studies were performed on their interaction with the air-liquid interface of the lungs, in particular with the surfactant components SP-A and SP-D. The increasing knowledge on protein-lipid-interaction for lipophilic and hydrophobic food and inhalant allergens on the basis of their particular structure, of their capacity to be integral part of membranes (like the oleosins), and their ability to interact with membranes, surfactant components, and transport lipids (like the lipid transfer proteins) are essential to eventually clarify allergy and asthma development.
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Affiliation(s)
- Uta Jappe
- Division of Clinical and Molecular Allergology, Research Center Borstel, Leibniz Lung Center, Airway Research Center North, German Center for Lung Research, Borstel, Germany
- Interdisciplinary Allergy Outpatient Clinic, Department of Pneumology, University of Luebeck, Borstel, Germany
| | - Christian Schwager
- Division of Clinical and Molecular Allergology, Research Center Borstel, Leibniz Lung Center, Airway Research Center North, German Center for Lung Research, Borstel, Germany
| | - Andra B. Schromm
- Division of Immunobiophysics, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Nestor González Roldán
- Junior Research Group of Allergobiochemistry, Research Center Borstel, Leibniz Lung Center, Airway Research Center North, German Center for Lung Research, Borstel, Germany
| | - Karina Stein
- Division of Innate Immunity, Research Center Borstel, Leibniz Lung Center, Airway Research Center North, German Center for Lung Research, Borstel, Germany
| | - Holger Heine
- Division of Innate Immunity, Research Center Borstel, Leibniz Lung Center, Airway Research Center North, German Center for Lung Research, Borstel, Germany
| | - Katarzyna A. Duda
- Junior Research Group of Allergobiochemistry, Research Center Borstel, Leibniz Lung Center, Airway Research Center North, German Center for Lung Research, Borstel, Germany
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31
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Plundrich NJ, Cook BT, Maleki SJ, Fourches D, Lila MA. Binding of peanut allergen Ara h 2 with Vaccinium fruit polyphenols. Food Chem 2019; 284:287-295. [PMID: 30744860 DOI: 10.1016/j.foodchem.2019.01.081] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/08/2019] [Accepted: 01/08/2019] [Indexed: 01/30/2023]
Abstract
The potential for 42 different polyphenols found in Vaccinium fruits to bind to peanut allergen Ara h 2 and inhibit IgE binding epitopes was investigated using cheminformatics techniques. Out of 12 predicted binders, delphinidin-3-glucoside, cyanidin-3-glucoside, procyanidin C1, and chlorogenic acid were further evaluated in vitro. Circular dichroism, UV-Vis spectroscopy, and immunoblotting determined their capacity to (i) bind to Ara h 2, (ii) induce protein secondary structural changes, and (iii) inhibit IgE binding epitopes. UV-Vis spectroscopy clearly indicated that procyanidin C1 and chlorogenic acid interacted with Ara h 2, and circular dichroism results suggested that interactions with these polyphenols resulted in changes to Ara h 2 secondary structures. Immunoblotting showed that procyanidin C1 and chlorogenic acid bound to Ara h 2 significantly decreased the IgE binding capacity by 37% and 50%, respectively. These results suggest that certain polyphenols can inhibit IgE recognition of Ara h 2 by obstructing linear IgE epitopes.
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Affiliation(s)
- Nathalie J Plundrich
- Plants for Human Health Institute, Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA
| | - Bethany T Cook
- Department of Chemistry, Bioinformatics Research Center, North Carolina State University, Raleigh, NC 27695, USA
| | - Soheila J Maleki
- United States Department of Agriculture-Agricultural Research Service-Southern Regional Research Center, New Orleans, LA 70124, USA
| | - Denis Fourches
- Department of Chemistry, Bioinformatics Research Center, North Carolina State University, Raleigh, NC 27695, USA
| | - Mary Ann Lila
- Plants for Human Health Institute, Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA.
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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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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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Shen M, Joshi AA, Vannam R, Dixit CK, Hamilton RG, Kumar CV, Rusling JF, Peczuh MW. Epitope-Resolved Detection of Peanut-Specific IgE Antibodies by Surface Plasmon Resonance Imaging. Chembiochem 2018; 19:199-202. [PMID: 29232483 PMCID: PMC5965296 DOI: 10.1002/cbic.201700513] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Indexed: 12/19/2022]
Abstract
Peanut allergy can be life-threatening and is mediated by allergen-specific immunoglobulin E (IgE) antibodies. Investigation of IgE antibody binding to allergenic epitopes can identify specific interactions underlying the allergic response. Here, we report a surface plasmon resonance imaging (SPRi) immunoassay for differentiating IgE antibodies by epitope-resolved detection. IgE antibodies were first captured by magnetic beads bearing IgE ϵ-chain-specific antibodies and then introduced into an SPRi array immobilized with epitopes from the major peanut allergen glycoprotein Arachis hypogaea h2 (Ara h2). Differential epitope responses were achieved by establishing a binding environment that minimized cross-reactivity while maximizing analytical sensitivity. IgE antibody binding to each Ara h2 epitope was distinguished and quantified from patient serum samples (10 μL each) in a 45 min assay. Excellent correlation of Ara h2-specific IgE values was found between ImmunoCAP assays and the new SPRi method.
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Affiliation(s)
- Min Shen
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Amit A Joshi
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Raghu Vannam
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Chandra K Dixit
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Robert G Hamilton
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Challa V Kumar
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - James F Rusling
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, 06032, USA
| | - Mark W Peczuh
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
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Mazzucchelli G, Holzhauser T, Cirkovic Velickovic T, Diaz‐Perales A, Molina E, Roncada P, Rodrigues P, Verhoeckx K, Hoffmann‐Sommergruber K. Current (Food) Allergenic Risk Assessment: Is It Fit for Novel Foods? Status Quo and Identification of Gaps. Mol Nutr Food Res 2018; 62:1700278. [PMID: 28925060 PMCID: PMC5814866 DOI: 10.1002/mnfr.201700278] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/28/2017] [Indexed: 01/08/2023]
Abstract
Food allergies are recognized as a global health concern. In order to protect allergic consumers from severe symptoms, allergenic risk assessment for well-known foods and foods containing genetically modified ingredients is installed. However, population is steadily growing and there is a rising need to provide adequate protein-based foods, including novel sources, not yet used for human consumption. In this context safety issues such as a potential increased allergenic risk need to be assessed before marketing novel food sources. Therefore, the established allergenic risk assessment for genetically modified organisms needs to be re-evaluated for its applicability for risk assessment of novel food proteins. Two different scenarios of allergic sensitization have to be assessed. The first scenario is the presence of already known allergenic structures in novel foods. For this, a comparative assessment can be performed and the range of cross-reactivity can be explored, while in the second scenario allergic reactions are observed toward so far novel allergenic structures and no reference material is available. This review summarizes the current analytical methods for allergenic risk assessment, highlighting the strengths and limitations of each method and discussing the gaps in this assessment that need to be addressed in the near future.
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Affiliation(s)
- Gabriel Mazzucchelli
- Laboratory of Mass Spectrometry – MolSysDepartment of ChemistryUniversity of LiegeLiegeBelgium
| | | | - Tanja Cirkovic Velickovic
- Center of Excellence for Molecular Food SciencesUniversity of Belgrade – Faculty of ChemistryBelgradeSerbia
- Ghent University Global CampusYeonsu‐guIncheonSouth Korea
| | | | | | - Paola Roncada
- Istituto Sperimentale Italiano Lazzaro SpallanzaniMilanoItaly
| | - Pedro Rodrigues
- CCMARCenter of Marine ScienceUniversity of AlgarveFaroPortugal
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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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Identification of a common Ara h 3 epitope recognized by both the capture and the detection monoclonal antibodies in an ELISA detection kit. PLoS One 2017; 12:e0182935. [PMID: 28800361 PMCID: PMC5553815 DOI: 10.1371/journal.pone.0182935] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Accepted: 07/21/2017] [Indexed: 11/30/2022] Open
Abstract
Allergy to peanuts has become a common and severe problem, especially in westernized countries. In this study, we evaluated the target and epitope specificity of the capture and detection mouse monoclonal antibodies (mAbs) used in a commercial peanut allergen detection platform. We first identified the target of these antibodies as Ara h 3 and then used an overlapping peptide array of Ara h 3 to determine the antibody-binding epitopes. Further amino acids critical for the binding via alanine substitutions at individual amino acid residues within the epitope were mapped. Finally, inhibition ELISA and inhibition immunoblotting using a recombinant Ara h 3 protein were performed to confirm these results. Surprisingly, the capture and detection mAbs showed identical binding characteristics and were presumed to represent two isolates of the same clone, a notion supported by both isoelectric focusing electrophoresis and Liquid chromatography–mass spectrometry experiments. The simultaneous binding of a pair of identical mAbs to an individual allergen such as Ara h3 is attributed to the multivalency of the analyte and has implications for developing diagnostic assays for additional multimeric allergens.
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40
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Multiple epitope presentation and surface density control enabled by chemoselective immobilization lead to enhanced performance in IgE-binding fingerprinting on peptide microarrays. Anal Chim Acta 2017; 983:189-197. [DOI: 10.1016/j.aca.2017.06.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/09/2017] [Accepted: 06/16/2017] [Indexed: 11/17/2022]
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Filep S, Block DS, Smith BRE, King EM, Commins S, Kulis M, Vickery BP, Chapman MD. Specific allergen profiles of peanut foods and diagnostic or therapeutic allergenic products. J Allergy Clin Immunol 2017; 141:626-631.e7. [PMID: 28709968 DOI: 10.1016/j.jaci.2017.05.049] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 05/08/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Generic immunoassays for peanut cannot discriminate between allergen levels in peanut-derived food products or therapeutics. Clinical trials of oral immunotherapy (OIT) are strengthened by using standardized peanut preparations with defined doses of major allergens. OBJECTIVE This article describes measurement of Ara h 1, Ara h 2, and Ara h 6 in peanut foods and in peanut flour extracts used for allergy diagnosis and OIT. METHODS Monoclonal antibody-based enzyme immunoassays for Ara h 1, Ara h 2, and Ara h 6 were used to compare allergen levels in peanut (n = 16) and tree nut (n = 16) butter, peanut flour (n = 11), oils (n = 8), extracts used for diagnosis and OIT (n = 5), and the National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387. RESULTS Roasted peanut butters contained 991 to 21,406 μg/g Ara h 1 and exceeded Ara h 2 and Ara h 6 levels by 2- to 4-fold. Similarly, National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387 contained 11,275 μg/g Ara h 1, 2,522 μg/g Ara h 2, and 2,036 μg/g Ara h 6. In contrast, peanut flours contained 787 to 14,631 μg/g Ara h 2 and exceeded Ara h 1 levels by 2- to 20-fold. Flour extracts used for OIT contained 394 to 505 μg/mL Ara h 1, 1,187 to 5,270 μg/mL Ara h 2, and 1,104 to 8,092 μg/mL Ara h 6. In most cases specific peanut allergens were not detected in tree nut butters or peanut oils. CONCLUSIONS The results show marked differences in specific peanut allergen profiles in peanut butter and flour and peanut preparations for clinical use. Roasting can increase Ara h 1 levels in peanut butter. Variability in allergen levels could affect the outcome of clinical trials of peanut OIT, especially with respect to Ara h 1. Specific allergen measurements will improve standardization and provide accurate dosing of peanut preparations that are being used for OIT.
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Affiliation(s)
| | | | | | - Eva M King
- INDOOR Biotechnologies, Charlottesville, Va
| | - Scott Commins
- Division of Pediatric Allergy, University of Virginia Health Sciences Center, Charlottesville, Va
| | - Michael Kulis
- Department of Pediatric Allergy, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Brian P Vickery
- Department of Pediatric Allergy, University of North Carolina School of Medicine, Chapel Hill, NC
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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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Zhang Y, Fan Y. A Mutant Sumo Facilitates Quick Plasmid Construction for Expressing Proteins with Native N-termini After Tag Removal. Mol Biotechnol 2017; 59:159-167. [DOI: 10.1007/s12033-017-9998-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Zhang W, Zhu Q, Zhang T, Cai Q, Chen Q. Thermal processing effects on peanut allergen Ara h 2 allergenicity in mice and its antigenic epitope structure. Food Chem 2016; 212:657-62. [DOI: 10.1016/j.foodchem.2016.06.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/20/2016] [Accepted: 06/13/2016] [Indexed: 10/21/2022]
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45
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Peanut protein extraction conditions strongly influence yield of allergens Ara h 1 and 2 and sensitivity of immunoassays. Food Chem 2016; 221:335-344. [PMID: 27979211 DOI: 10.1016/j.foodchem.2016.10.063] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 09/12/2016] [Accepted: 10/13/2016] [Indexed: 11/21/2022]
Abstract
The clinical importance of peanut (Arachis hypogaea) allergies demands standardized allergen extraction protocols. We determined the effectiveness of common extraction conditions (20 buffers, defatting reagents, extraction time/temperatures, processing, extraction repeats) on crude protein and Ara h 1 and 2 yields. Despite similar 1D-gel profiles, defatting with n-hexane resulted in significantly higher yields of crude protein, Ara h 1, and Ara h 2 than with diethyl ether. The yields were affected by the composition and pH of the extraction buffers and other conditions, but crude protein yield did not always correlate with Ara h 1 and 2 yields. Denaturants, reducing agents, acidic buffers, and thermal processing of peanuts perturbed allergen quantification in ELISAs, probably via exposure of additional epitopes. Allergen detection in 2D-Western blots with PBS resulted in greater sensitivity than with TBS or Tris. We recommend that allergen extraction conditions be selected based on the research question being investigated.
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46
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Maruyama N, Nakagawa T, Ito K, Cabanos C, Borres MP, Movérare R, Tanaka A, Sato S, Ebisawa M. Measurement of specific IgE antibodies to Ses i 1 improves the diagnosis of sesame allergy. Clin Exp Allergy 2016; 46:163-71. [PMID: 26310924 DOI: 10.1111/cea.12626] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 07/30/2015] [Accepted: 08/13/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND The number of reported cases of allergic reactions to sesame seeds (Sesamum indicum) has increased significantly. The specific IgE tests and skin prick tests presently available for diagnosis of sesame allergy are all based on crude sesame extract and are limited by their low clinical specificity. Thus, oral food challenge (OFC) is still the gold standard in the diagnosis. OBJECTIVE The aim was to identify the allergen components useful to diagnose sesame-allergic children with the goal to reduce the number of OFCs needed. METHODS Ninety-two sesame-sensitized children were consecutively enrolled and diagnosed based on OFC or convincing history. Specific IgE to purified native 11S globulin (nSes i 11S), 7S globulin (nSes i 7S), 2S albumin (nSes i 2S), and two recombinant 2S albumins (rSes i 1 and rSes i 2) was measured by ELISA and/or ImmunoCAP (rSes i 1/streptavidin application). RESULTS Based on area under curve (AUC) values from receiver operating characteristic (ROC) analysis, rSes i 1 was shown to have the best diagnostic performance of the allergen components in ELISA. The experimental rSes i 1 ImmunoCAP test had larger AUC (0.891; 95% CI, 0.826-0.955) compared to the commercially available sesame ImmunoCAP (0.697; 95% CI, 0.589-0.805). The clinical sensitivity and specificity for the rSes i 1 ImmunoCAP test at optimal cut-off (3.96 kUA /L) were 86.1% and 85.7%, respectively. CONCLUSION AND CLINICAL RELEVANCE Sensitization to Ses i 1 is strongly associated with clinical sesame allergy. Measurement of specific IgE to rSes i 1 could reduce the numbers of OFCs needed.
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Affiliation(s)
- N Maruyama
- Laboratory of Food Quality Design and Development, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
| | - T Nakagawa
- Department of Allergy, Aichi Children's Health and Medical Center, Obu, Aichi, Japan
| | - K Ito
- Department of Allergy, Aichi Children's Health and Medical Center, Obu, Aichi, Japan
| | - C Cabanos
- Laboratory of Food Quality Design and Development, Graduate School of Agriculture, Kyoto University, Uji, Kyoto, Japan
| | - M P Borres
- Thermo Fisher Scientific, Uppsala, Sweden.,Department of Maternal and Child Health, Uppsala University, Uppsala, Sweden
| | - R Movérare
- Thermo Fisher Scientific, Uppsala, Sweden.,Department of Medical Sciences, Respiratory Medicine and Allergology, Uppsala University, Uppsala, Sweden
| | - A Tanaka
- Thermo Fisher Scientific, Tokyo, Japan
| | - S Sato
- Department of Allergy, Clinical Research Center for Allergology and Rheumatology, Sagamihara National Hospital, Sagamihara, Kanagawa, Japan
| | - M Ebisawa
- Department of Allergy, Clinical Research Center for Allergology and Rheumatology, Sagamihara National Hospital, Sagamihara, Kanagawa, Japan
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47
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Influence of heat treatment on the structure and core IgE-binding epitopes of rAra h 2.02. Food Chem 2016; 202:404-8. [DOI: 10.1016/j.foodchem.2016.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 12/26/2015] [Accepted: 02/01/2016] [Indexed: 01/15/2023]
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48
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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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Long F, Yang X, Sun J, Zhong Q, Wei J, Qu P, Yue T. Effects of combined high pressure and thermal treatment on the allergenic potential of peanut in a mouse model of allergy. INNOV FOOD SCI EMERG 2016. [DOI: 10.1016/j.ifset.2016.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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50
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Tao B, Bernardo K, Eldi P, Chegeni N, Wiese M, Colella A, Kral A, Hayball J, Smith W, Forsyth K, Chataway T. Extended boiling of peanut progressively reduces IgE allergenicity while retaining T cell reactivity. Clin Exp Allergy 2016; 46:1004-14. [DOI: 10.1111/cea.12740] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/09/2016] [Accepted: 03/31/2016] [Indexed: 11/30/2022]
Affiliation(s)
- B. Tao
- Department of Paediatrics and Child Health; Flinders University of South Australia; Adelaide SA Australia
- Flinders Proteomics Facility; Department of Human Physiology; Flinders University of South Australia; Adelaide SA Australia
| | - K. Bernardo
- Flinders Proteomics Facility; Department of Human Physiology; Flinders University of South Australia; Adelaide SA Australia
| | - P. Eldi
- School of Pharmacy and Medical Sciences; University of South Australia; Adelaide SA Australia
| | - N. Chegeni
- Flinders Proteomics Facility; Department of Human Physiology; Flinders University of South Australia; Adelaide SA Australia
| | - M. Wiese
- School of Pharmacy and Medical Sciences; University of South Australia; Adelaide SA Australia
| | - A. Colella
- Department of Immunology; Flinders University of South Australia; Adelaide SA Australia
| | - A. Kral
- Department and School of Medicine; University of Adelaide; Adelaide SA Australia
| | - J. Hayball
- School of Pharmacy and Medical Sciences; University of South Australia; Adelaide SA Australia
| | - W. Smith
- Department and School of Medicine; University of Adelaide; Adelaide SA Australia
| | - K. Forsyth
- Department of Paediatrics and Child Health; Flinders University of South Australia; Adelaide SA Australia
| | - T. Chataway
- Flinders Proteomics Facility; Department of Human Physiology; Flinders University of South Australia; Adelaide SA Australia
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