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Abu Risha M, Rick EM, Plum M, Jappe U. Legume Allergens Pea, Chickpea, Lentil, Lupine and Beyond. Curr Allergy Asthma Rep 2024; 24:527-548. [PMID: 38990406 PMCID: PMC11364600 DOI: 10.1007/s11882-024-01165-7] [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] [Accepted: 06/26/2024] [Indexed: 07/12/2024]
Abstract
PURPOSE OF THE REVIEW In the last decade, an increasing trend towards a supposedly healthier vegan diet could be observed. However, recently, more cases of allergic reactions to plants and plant-based products such as meat-substitution products, which are often prepared with legumes, were reported. Here, we provide the current knowledge on legume allergen sources and the respective single allergens. We answer the question of which legumes beside the well-known food allergen sources peanut and soybean should be considered for diagnostic and therapeutic measures. RECENT FINDINGS These "non-priority" legumes, including beans, pea, lentils, chickpea, lupine, cowpea, pigeon pea, and fenugreek, are potentially new important allergen sources, causing mild-to-severe allergic reactions. Severe reactions have been described particularly for peas and lupine. An interesting aspect is the connection between anaphylactic reactions and exercise (food-dependent exercise-induced anaphylaxis), which has only recently been highlighted for legumes such as soybean, lentils and chickpea. Most allergic reactions derive from IgE cross-reactions to homologous proteins, for example between peanut and lupine, which is of particular importance for peanut-allergic individuals ignorant to these cross-reactions. From our findings we conclude that there is a need for large-scale studies that are geographically distinctive because most studies are case reports, and geographic differences of allergic diseases towards these legumes have already been discovered for well-known "Big 9" allergen sources such as peanut and soybean. Furthermore, the review illustrates the need for a better molecular diagnostic for these emerging non-priority allergen sources to evaluate IgE cross-reactivities to known allergens and identify true allergic reactions.
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Affiliation(s)
- Marua Abu Risha
- Clinical and Molecular Allergology, Priority Research Area Chronic Lung Diseases, Research Center Borstel, Borstel, Germany
- German Center for Lung Research (DZL), Airway Research Center North (ARCN), Borstel, Germany
| | - Eva-Maria Rick
- Clinical and Molecular Allergology, Priority Research Area Chronic Lung Diseases, Research Center Borstel, Borstel, Germany
- German Center for Lung Research (DZL), Airway Research Center North (ARCN), Borstel, Germany
| | - Melanie Plum
- Clinical and Molecular Allergology, Priority Research Area Chronic Lung Diseases, Research Center Borstel, Borstel, Germany
- German Center for Lung Research (DZL), Airway Research Center North (ARCN), Borstel, Germany
| | - Uta Jappe
- Clinical and Molecular Allergology, Priority Research Area Chronic Lung Diseases, Research Center Borstel, Borstel, Germany.
- German Center for Lung Research (DZL), Airway Research Center North (ARCN), Borstel, Germany.
- Interdisciplinary Allergy Outpatient Clinic, Department of Pneumology, University of Lübeck, Lübeck, Germany.
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Mattison CP, Dupre RA, Clermont K, Gibbons JG, Yu JH. Proteomic characterization of peanut flour fermented by Rhizopus oryzae. Heliyon 2024; 10:e34793. [PMID: 39144949 PMCID: PMC11320294 DOI: 10.1016/j.heliyon.2024.e34793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 08/16/2024] Open
Abstract
Fermentation alters the protein content and composition of foods. To characterize fungal catabolism of peanut proteins, defatted peanut flour was fermented by Rhizopus oryzae (R. oryzae) for up to 48 h and evaluated by SDS-PAGE, mass spectrometry, and antibody binding. A clear change in peanut protein migration was observed by SDS-PAGE after 16 h of fermentation. Mass spectrometric analysis indicated changes in allergen peptides and R. oryzae proteins. Several low molecular weight allergen fragments produced during fermentation were identified by mass spectrometry. Immunoassays using anti-peanut allergen antibodies demonstrated reduced allergen content as early as 16 h of fermentation. However, ELISA with peanut allergic IgE indicated only slightly reduced allergen binding even after 48 h. These results indicate that while R. oryzae fermentation efficiently metabolizes peanut allergens, significant IgE binding remains in lower molecular mass peptides, and therefore R. oryzae fermented peanut products would not be safe for peanut allergic individuals.
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Affiliation(s)
- Christopher P. Mattison
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, FPSQ, New Orleans, LA, 70124, USA
| | - Rebecca A. Dupre
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, FPSQ, New Orleans, LA, 70124, USA
- Oak Ridge Institute for Science and Education, U.S. Department of Energy, Oak Ridge, TN, 37831, USA
| | - Kristen Clermont
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, FPSQ, New Orleans, LA, 70124, USA
- Oak Ridge Institute for Science and Education, U.S. Department of Energy, Oak Ridge, TN, 37831, USA
- Department of Biology, La Salle University, Philadelphia, PA, 19141, USA
| | - John G. Gibbons
- Department of Food Science, College of Natural Sciences, University of Massachusetts, Amherst, MA, 01003, USA
| | - Jae-Hyuk Yu
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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3
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Tuppo L, Alessandri C, Zaccaro L, Giangrieco I, Tamburrini M, Mari A, Ciardiello MA. Isolation, Characterization and IgE Binding of Two 2S Albumins of Pomegranate Seeds. Foods 2024; 13:1965. [PMID: 38998471 PMCID: PMC11241328 DOI: 10.3390/foods13131965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/14/2024] [Accepted: 06/19/2024] [Indexed: 07/14/2024] Open
Abstract
Literature reports suggest that the presence of proteins in pomegranate seeds is responsible for sensitization and IgE-mediated allergic reactions. The objective of this study was the analysis of a pomegranate seed extract and the isolation and characterization of proteins contained in high amounts. The extract characterization showed a protein profile with main bands at about 18 kDa and below 10 kDa upon SDS-PAGE, and molecules were recognized by specific IgEs upon immunoblotting. Then, two new 2S albumins, a monomeric and a heterodimeric one, were isolated by using classical biochemical methods. They were identified via direct protein sequencing and mass spectrometry, and their primary structure was analyzed and compared with homologous allergenic proteins via bioinformatics. In an Italian population of 703 suspected allergic patients, analyzed by using the FABER® test, the frequency of sensitization to the monomeric and heterodimeric 2S albumins was 1.7% and 0.28%, respectively. This study reports for the first time the isolation and characterization of two 2S albumins from pomegranate seeds. The clinical relevance of these molecules needs further investigation, for instance in populations having different exposures and allergy profiles.
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Affiliation(s)
- Lisa Tuppo
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
| | - Claudia Alessandri
- Associated Centers for Molecular Allergology (CAAM), 00100 Rome, Italy; (C.A.); (A.M.)
| | - Laura Zaccaro
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), 80131 Naples, Italy;
| | - Ivana Giangrieco
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
| | - Maurizio Tamburrini
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
| | - Adriano Mari
- Associated Centers for Molecular Allergology (CAAM), 00100 Rome, Italy; (C.A.); (A.M.)
| | - Maria Antonietta Ciardiello
- Institute of Biosciences and BioResources (IBBR), National Research Council of Italy (CNR), 80131 Naples, Italy; (L.T.); (I.G.); (M.T.)
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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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Charoenkwan P, Chumnanpuen P, Schaduangrat N, Shoombuatong W. Accelerating the identification of the allergenic potential of plant proteins using a stacked ensemble-learning framework. J Biomol Struct Dyn 2024:1-13. [PMID: 38385478 DOI: 10.1080/07391102.2024.2318482] [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: 12/07/2023] [Accepted: 02/08/2024] [Indexed: 02/23/2024]
Abstract
Plant-allergenic proteins (PAPs) have the potential to induce allergic reactions in certain individuals. While these proteins are generally innocuous for the majority of people, they can elicit an immune response in those with particular sensitivities. Thus, screening and prioritizing the allergenic potential of plant proteins is indispensable for the development of diagnostic tools, therapeutic interventions or medications to treat allergic reactions. However, investigating the allergenic potential of plant proteins based on experimental methods is costly and labour-intensive. Therefore, we develop StackPAP, a three-layer stacking ensemble framework for accurate large-scale identification of PAPs. In StackPAP, at the first layer, we conducted a comprehensive analysis of an extensive set of feature descriptors. Subsequently, we selected and fused five potential sequence-based feature descriptors, including amphiphilic pseudo-amino acid composition, dipeptide deviation from expected mean, amino acid composition, pseudo amino acid composition and dipeptide composition. Additionally, we applied an efficient genetic algorithm (GA-SAR) to determine informative feature sets. In the second layer, 12 powerful machine learning (ML) methods, in combination with all the informative feature sets, were employed to construct a pool of base classifiers. Finally, 13 potential base classifiers were selected using the GA-SAR method and combined to develop the final meta-classifier. Our experimental results revealed the promising prediction performance of StackPAP, with an accuracy, Matthew's correlation coefficient and AUC of 0.984, 0.969 and 0.993, respectively, as judged by the independent test dataset. In conclusion, both cross-validation and independent test results indicated the superior performance of StackPAP compared with several ML-based classifiers. To accelerate the identification of the allergenicity of plant proteins, we developed a user-friendly web server for StackPAP (https://pmlabqsar.pythonanywhere.com/StackPAP). We anticipate that StackPAP will be an efficient and useful tool for rapidly screening PAPs from a vast number of plant proteins.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Phasit Charoenkwan
- Modern Management and Information Technology, College of Arts, Media and Technology, Chiang Mai University, Thailand
| | - Pramote Chumnanpuen
- Department of Zoology, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Omics Center for Agriculture, Bioresources, Food, and Health, Kasetsart University (OmiKU), Bangkok, Thailand
| | - Nalini Schaduangrat
- Center for Research Innovation and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
| | - Watshara Shoombuatong
- Center for Research Innovation and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand
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6
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Yan Y, Li L, Long C, Dong Y, Li J, Shen C, Zhao Y, Zhao J, Wang J, Xiong A, Li X, Chen H, He S. A novel IgE epitope-specific antibodies-based sandwich ELISA for sensitive measurement of immunoreactivity changes of peanut allergen Ara h 2 in processed foods. Front Nutr 2024; 11:1323553. [PMID: 38439921 PMCID: PMC10910080 DOI: 10.3389/fnut.2024.1323553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 02/05/2024] [Indexed: 03/06/2024] Open
Abstract
Background Peanut is an important source of dietary protein for human beings, but it is also recognized as one of the eight major food allergens. Binding of IgE antibodies to specific epitopes in peanut allergens plays important roles in initiating peanut-allergic reactions, and Ara h 2 is widely considered as the most potent peanut allergen and the best predictor of peanut allergy. Therefore, Ara h 2 IgE epitopes can serve as useful biomarkers for prediction of IgE-binding variations of Ara h 2 and peanut in foods. This study aimed to develop and validate an IgE epitope-specific antibodies (IgE-EsAbs)-based sandwich ELISA (sELISA) for detection of Ara h 2 and measurement of Ara h 2 IgE-immunoreactivity changes in foods. Methods DEAE-Sepharose Fast Flow anion-exchange chromatography combining with SDS-PAGE gel extraction were applied to purify Ara h 2 from raw peanut. Hybridoma and epitope vaccine techniques were employed to generate a monoclonal antibody against a major IgE epitope of Ara h 2 and a polyclonal antibody against 12 IgE epitopes of Ara h 2, respectively. ELISA was carried out to evaluate the target binding and specificity of the generated IgE-EsAbs. Subsequently, IgE-EsAbs-based sELISA was developed to detect Ara h 2 and its allergenic residues in food samples. The IgE-binding capacity of Ara h 2 and peanut in foods was determined by competitive ELISA. The dose-effect relationship between the Ara h 2 IgE epitope content and Ara h 2 (or peanut) IgE-binding ability was further established to validate the reliability of the developed sELISA in measuring IgE-binding variations of Ara h 2 and peanut in foods. Results The obtained Ara h 2 had a purity of 94.44%. Antibody characterization revealed that the IgE-EsAbs recognized the target IgE epitope(s) of Ara h 2 and exhibited high specificity. Accordingly, an IgE-EsAbs-based sELISA using these antibodies was able to detect Ara h 2 and its allergenic residues in food samples, with high sensitivity (a limit of detection of 0.98 ng/mL), accuracy (a mean bias of 0.88%), precision (relative standard deviation < 16.50%), specificity, and recovery (an average recovery of 98.28%). Moreover, the developed sELISA could predict IgE-binding variations of Ara h 2 and peanut in foods, as verified by using sera IgE derived from peanut-allergic individuals. Conclusion This novel immunoassay could be a user-friendly method to monitor low level of Ara h 2 and to preliminary predict in vitro potential allergenicity of Ara h 2 and peanut in processed foods.
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Affiliation(s)
- Yan Yan
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Liming Li
- Department of Dermatology, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Caiyun Long
- Department of Laboratory, Ganzhou Center for Disease Control and Prevention, Ganzhou, China
| | - Yaping Dong
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Jinyu Li
- Department of Dermatology, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Caiyi Shen
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Yiqian Zhao
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Jiangqiang Zhao
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Jianbin Wang
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Anqi Xiong
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Xin Li
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Shengfa He
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
- Key Laboratory of Environment and Health of Ganzhou, Gannan Medical University, Ganzhou, China
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7
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Song M, Zhang Y, Zhu W, Zhou W, Li X, Yang A, Tong P, Wu Z, Chen H. Mass Spectrometry Analysis on the Breakage of Allergens in High-Molecular-Mass Polymer of Roasted Peanuts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:3142-3149. [PMID: 38299554 DOI: 10.1021/acs.jafc.3c07007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Peanut allergy is a prevalent and concerning food allergy. Roasting can introduce structural changes to peanut allergens, affecting their allergenicity, but the structure on the primary structure is unclear. Here, the breakage sites were identified by mass spectrometry and software tools, and structural changes were simulated by molecular dynamics and displayed by PyMOL software. Results revealed that the appearance frequencies of L, Q, F, and E were high at the N-terminal of the breakage site, while S and E were dominant at the C-terminal. In the conformational structure, breakage sites were found close to disulfide bonds and the Cupin domains of Ara h 1 and Ara h 3. The breakage of allergens destroyed linear epitopes and might change the conformation of epitopes, which could influence peanuts' potential allergenicity.
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Affiliation(s)
- Min Song
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Weichao Zhu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Wenlong Zhou
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Xin Li
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Ping Tong
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
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Geng Q, Zhang Y, McClements DJ, Zhou W, Dai T, Wu Z, Chen H. Investigation of peanut allergen-procyanidin non-covalent interactions: Impact on protein structure and in vitro allergenicity. Int J Biol Macromol 2024; 258:128340. [PMID: 38000575 DOI: 10.1016/j.ijbiomac.2023.128340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 11/26/2023]
Abstract
Interactions between plant polyphenols and food allergens may be a new way to alleviate food allergies. The non-covalent interactions between the major allergen from peanut (Ara h 2) with procyanidin dimer (PA2) were therefore characterized using spectroscopic, thermodynamic, and molecular simulation analyses. The main interaction between the Ara h 2 and PA2 was hydrogen bonding. PA2 statically quenched the intrinsic fluorescence intensity and altered the conformation of the Ara h 2, leading to a more disordered polypeptide structure with a lower surface hydrophobicity. In addition, the in vitro allergenicity of the Ara h 2-PA2 complex was investigated using enzyme-linked immunosorbent assay (ELISA) kits. The immunoglobulin E (IgE) binding capacity of Ara h 2, as well as the release of allergenic cytokines, decreased after interacting with PA2. When the ratio of Ara h 2-to-PA2 was 1:50, the IgE binding capacity was reduced by around 43 %. This study provides valuable insights into the non-covalent interactions between Ara h 2 and PA2, as well as the potential mechanism of action of the anti-allergic reaction caused by binding of the polyphenols to the allergens.
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Affiliation(s)
- Qin Geng
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | | | - Wenlong Zhou
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Taotao Dai
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China; Sino-German Joint Research Institute, Nanchang University, Nanchang, China.
| | - Hongbing Chen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China; Sino-German Joint Research Institute, Nanchang University, Nanchang, China
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9
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Yang P, Wang X, Wang H, Hu Y, Wen P, Tu Z. The decrease of Ara h 2 allergenicity by glycation is determined by reducing sugar chain length and isomers. Food Chem 2024; 432:137289. [PMID: 37659330 DOI: 10.1016/j.foodchem.2023.137289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 08/14/2023] [Accepted: 08/24/2023] [Indexed: 09/04/2023]
Abstract
The mechanism of the effect of reducing sugar chain length and isomers on the allergenicity of Ara h 2 after glycation was investigated. Ara h 2 was more prone to glycation with ribose which had a short chain length. The glycation sites of Ara h 2 after glycation with galactose were higher than the glycation sites in galactose's isomers-Ara h 2 conjugates, which might be affected by the configuration differences at position C-4 and the small steric effects in terminal groups -CHO of galactose. Ara h 2-ribose conjugate had the lowest allergenicity, and glycation with galactose was more capable of reducing Ara h 2 allergenicity than its isomers. The results indicated that glycation with ribose caused conformational epitope destruction and linear epitope masking of Ara h 2 greatly. Furthermore, since the small steric effects of -CHO, galactose was more capable of reducing Ara h 2 allergenicity than fructose. This study will provide a theoretical basis for selecting appropriate reducing sugars and preparing hypoallergenic products containing peanuts.
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Affiliation(s)
- Ping Yang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, Jiangxi 330047, China
| | - Xumei Wang
- College of Health, Jiangxi Normal University, Nanchang, Jiangxi 330022, China; National R&D Center of Freshwater Fish Processing and Engineering Research Center of Freshwater Fish High-value Utilization of Jiangxi Province, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
| | - Hui Wang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, Jiangxi 330047, China.
| | - Yueming Hu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, Jiangxi 330047, China
| | - Pingwei Wen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, Jiangxi 330047, China
| | - Zongcai Tu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, Jiangxi 330047, China; National R&D Center of Freshwater Fish Processing and Engineering Research Center of Freshwater Fish High-value Utilization of Jiangxi Province, Jiangxi Normal University, Nanchang, Jiangxi 330022, China
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10
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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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11
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Lokya V, Parmar S, Pandey AK, Sudini HK, Huai D, Ozias-Akins P, Foyer CH, Nwosu CV, Karpinska B, Baker A, Xu P, Liao B, Mir RR, Chen X, Guo B, Nguyen HT, Kumar R, Bera SK, Singam P, Kumar A, Varshney RK, Pandey MK. Prospects for developing allergen-depleted food crops. THE PLANT GENOME 2023; 16:e20375. [PMID: 37641460 DOI: 10.1002/tpg2.20375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 06/08/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023]
Abstract
In addition to the challenge of meeting global demand for food production, there are increasing concerns about food safety and the need to protect consumer health from the negative effects of foodborne allergies. Certain bio-molecules (usually proteins) present in food can act as allergens that trigger unusual immunological reactions, with potentially life-threatening consequences. The relentless working lifestyles of the modern era often incorporate poor eating habits that include readymade prepackaged and processed foods, which contain additives such as peanuts, tree nuts, wheat, and soy-based products, rather than traditional home cooking. Of the predominant allergenic foods (soybean, wheat, fish, peanut, shellfish, tree nuts, eggs, and milk), peanuts (Arachis hypogaea) are the best characterized source of allergens, followed by tree nuts (Juglans regia, Prunus amygdalus, Corylus avellana, Carya illinoinensis, Anacardium occidentale, Pistacia vera, Bertholletia excels), wheat (Triticum aestivum), soybeans (Glycine max), and kidney beans (Phaseolus vulgaris). The prevalence of food allergies has risen significantly in recent years including chance of accidental exposure to such foods. In contrast, the standards of detection, diagnosis, and cure have not kept pace and unfortunately are often suboptimal. In this review, we mainly focus on the prevalence of allergies associated with peanut, tree nuts, wheat, soybean, and kidney bean, highlighting their physiological properties and functions as well as considering research directions for tailoring allergen gene expression. In particular, we discuss how recent advances in molecular breeding, genetic engineering, and genome editing can be used to develop potential low allergen food crops that protect consumer health.
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Affiliation(s)
- Vadthya Lokya
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Sejal Parmar
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Arun K Pandey
- College of Life Science of China Jiliang University (CJLU), Hangzhou, China
| | - Hari K Sudini
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
| | - Dongxin Huai
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Peggy Ozias-Akins
- Horticulture Department, The University of Georgia Tifton Campus, Tifton, GA, USA
| | - Christine H Foyer
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, UK
| | | | - Barbara Karpinska
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, UK
| | - Alison Baker
- Centre for Plant Sciences and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Pei Xu
- College of Life Science of China Jiliang University (CJLU), Hangzhou, China
| | - Boshou Liao
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Reyazul Rouf Mir
- Division of Genetics and Plant Breeding, Faculty of Agriculture, Sher-e-Kashmir University of Agricultural Sciences and Technology, Srinagar, India
| | - Xiaoping Chen
- Guangdong Provincial Key Laboratory for Crops Genetic Improvement, Crops Research Institute of Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Baozhu Guo
- USDA-ARS, Crop Genetics and Breeding Research Unit, Tifton, GA, USA
| | - Henry T Nguyen
- Division of Plant Sciences and National Center for Soybean Biotechnology, University of Missouri, Columbia, MO, USA
| | - Rakesh Kumar
- Department of Life Sciences, Central University of Karnataka, Gulbarga, India
| | | | - Prashant Singam
- Department of Genetics, Osmania University, Hyderabad, India
| | - Anirudh Kumar
- Central Tribal University of Andhra Pradesh, Vizianagaram, Andhra Pradesh, India
| | - Rajeev K Varshney
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
- State Agricultural Biotechnology Centre, Crop Research Innovation Centre, Food Futures Institute, Murdoch University, Murdoch, Western Australia, Australia
| | - Manish K Pandey
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
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12
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Warmenhoven HJM, Hulsbos L, Dreskin SC, Akkerdaas JH, Versteeg SA, van Ree R. IgE cross-inhibition between Ara h 1 and Ara h 2 is explained by complex formation of both major peanut allergens. J Allergy Clin Immunol 2023; 152:436-444.e6. [PMID: 37028524 PMCID: PMC10528450 DOI: 10.1016/j.jaci.2023.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 03/10/2023] [Accepted: 03/31/2023] [Indexed: 04/09/2023]
Abstract
BACKGROUND Surprisingly, IgE cross-reactivity between the major peanut allergens Ara h 1, 2, and 3 has been reported despite very low sequence identities. OBJECTIVE We investigated the unexpected cross-reactivity between peanut major allergens. METHODS Cross-contamination of purified natural Ara h 1, 2, 3, and 6 was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Western blot test, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and sandwich enzyme-linked immunosorbent assay (ELISA). IgE cross-reactivity was studied with sera of peanut-allergic patients (n = 43) by ELISA and ImmunoCAP inhibition using both intact natural and recombinant allergens and synthetic peptides representing postulated Ara h 1 and Ara h 2 cross-reactive epitopes. RESULTS Both purified nAra h 1 and nAra h 3 were demonstrated to contain small but significant amounts of Ara h 2 and Ara h 6 (<1%) by sandwich ELISA, SDS-PAGE/Western blot analysis, and LC-MS/MS. IgE cross-inhibition between both 2S albumins and Ara h 1 and Ara h 3 was only observed when using natural purified allergens, not recombinant allergens or synthetic peptides. Apparent cross-reactivity was lost when purified nAra h 1 was pretreated under reducing conditions, suggesting that Ara h 2 and Ara h 6 contaminations may be covalently bound to Ara h 1 via disulfide interactions. CONCLUSION True cross-reactivity of both peanut 2S albumins with Ara h 1 and Ara h 3 could not be demonstrated. Instead, cross-contamination with small quantities was shown to be sufficient to cause significant cross-inhibition that can be misinterpreted as molecular cross-reactivity. Diagnostic tests using purified nAra h 1 and nAra h 3 can overestimate their importance as major allergens as a result of the presence of contaminating 2S albumins, making recombinant Ara h 1 and Ara h 3 a preferred alternative.
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Affiliation(s)
- Hans J M Warmenhoven
- HAL Allergy, J. H. Oortweg, Leiden, The Netherlands; Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Luuk Hulsbos
- HAL Allergy, J. H. Oortweg, Leiden, The Netherlands
| | - Stephen C Dreskin
- Department of Medicine, Division of Allergy and Clinical Immunology, University of Colorado-Denver, Aurora, Colo
| | - Jaap H Akkerdaas
- Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Serge A Versteeg
- Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Ronald van Ree
- Department of Experimental Immunology, Amsterdam University Medical Centers, Amsterdam, The Netherlands; Department of Otorhinolaryngology, Amsterdam University Medical Centers, Amsterdam, The Netherlands.
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13
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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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14
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Chaudhari HA, Mahatma MK, Antala V, Radadiya N, Ukani P, Tomar RS, Thawait LK, Singh S, Gangadhara K, Sakure A, Parihar A. Ethrel-induced release of fresh seed dormancy causes remodelling of amylase activity, proteomics, phytohormone and fatty acid profile of groundnut (Arachis hypogaea L.). PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2023; 29:829-842. [PMID: 37520814 PMCID: PMC10382464 DOI: 10.1007/s12298-023-01332-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/20/2023] [Accepted: 07/05/2023] [Indexed: 08/01/2023]
Abstract
It is important to have a short period of fresh seed dormancy in some of the groundnut species to counter pre-harvest sprouting (PHS). One of the main causes of PHS is the activation of ethylene-mediated pathways. To determine the effect of ethylene, the study was conducted and alterations in amylase, proteins and fatty acids were observed at the 0, 6, 12, and 24 h stages after ethrel administration. The result showed an increase in amylase activity, and the fatty acids profile showed a unique alteration pattern at different germination stages. Two-dimensional gel electrophoresis (2DGE) revealed differential expression of proteins at each stage. The trypsin digestion following spectral development through UPLC-MS/MS enabled identification of number of differentially expressed proteins. A total of 49 proteins were identified from 2DGE excised spots. The majority were belonged to seed storage-related proteins like Arah1, Arah2, AAI- domain containing protein, conglutin, Arah3/4, arachin, glycinin. Expression of lipoxygenase1, lipoxygenase9 and Arah2 genes were further confirmed by qRT-PCR which showed its involvement at transcript level. Up-regulation of lipoxygenase9 is correlated with decreased content of fatty acids during germination. Phytohormone detection revealed decrease in ABA, SA and JA content which are generally inhibitor of seed germination while GA, IAA and kinetin concentration increased revealing positive regulation of seed germination. We present an integrated view of proteomics, phytohormone profile, carbohydrate and lipid metabolism to unravel mechanism of fresh seed dormancy. Supplementary Information The online version contains supplementary material available at 10.1007/s12298-023-01332-6.
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Affiliation(s)
- Hemangini A. Chaudhari
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat 362001 India
- ICAR-Directorate of Groundnut Research, Junagadh, Gujarat 362001 India
| | - Mahesh Kumar Mahatma
- ICAR-Directorate of Groundnut Research, Junagadh, Gujarat 362001 India
- ICAR-National Research Centre on Seed Spices, Tabiji, Ajmer, 305206 India
| | - Virali Antala
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat 362001 India
| | - Nidhi Radadiya
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat 362001 India
| | - Piyush Ukani
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat 362001 India
| | - Rukam Singh Tomar
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat 362001 India
| | | | - Sushmita Singh
- ICAR-Directorate of Groundnut Research, Junagadh, Gujarat 362001 India
| | - K. Gangadhara
- ICAR-Directorate of Groundnut Research, Junagadh, Gujarat 362001 India
- ICAR-Central Tobacco Research Institute, Regional Station, Kandukur, Andhra Pradesh 533105 India
| | - Amar Sakure
- Department of Agricultural Biotechnology, Anand Agricultural University, Anand, Gujarat 38811 India
| | - Akrash Parihar
- Department of Agricultural Biotechnology, Anand Agricultural University, Anand, Gujarat 38811 India
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15
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Geng Q, Zhang Y, Song M, Zhou X, Tang Y, Wu Z, Chen H. Allergenicity of peanut allergens and its dependence on the structure. Compr Rev Food Sci Food Saf 2023; 22:1058-1081. [PMID: 36624611 DOI: 10.1111/1541-4337.13101] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 12/13/2022] [Accepted: 12/18/2022] [Indexed: 01/11/2023]
Abstract
Food allergies are a global food safety problem. Peanut allergies are common due, in part, to their popular utilization in the food industry. Peanut allergy is typically an immunoglobulin E-mediated reaction, and peanuts contain 17 allergens belonging to different families in peanut. In this review, we first introduce the mechanisms and management of peanut allergy, followed by the basic structures of associated allergens. Subsequently, we summarize methods of epitope localization for peanut allergens. These methods can be instrumental in speeding up the discovery of allergenicity-dependent structures. Many attempts have been made to decrease the allergenicity of peanuts. The structures of hypoallergens, which are manufactured during processing, were analyzed to strengthen the desensitization process and allergen immunotherapy. The identification of conformational epitopes is the bottleneck in both peanut and food allergies. Further, the identification and modification of such epitopes will lead to improved strategies for managing and preventing peanut allergy. Combining traditional wet chemistry research with structure simulation studies will help in the epitopes' localization.
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Affiliation(s)
- Qin Geng
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- College of Food Science and Technology, Nanchang University, Nanchang, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- College of Food Science and Technology, Nanchang University, Nanchang, China
| | - Min Song
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- College of Food Science and Technology, Nanchang University, Nanchang, China
| | - Xiaoya Zhou
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- College of Food Science and Technology, Nanchang University, Nanchang, China
| | - Yu Tang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, China
- College of Food Science and Technology, 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
| | - 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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16
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Zhou X, Ren L, Zhang Y, Zhang J, Li X, Yang A, Tong P, Wu Z, Chen H. Effect of Structural Targeted Modifications on the Potential Allergenicity of Peanut Allergen Ara h 2. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:836-845. [PMID: 36574959 DOI: 10.1021/acs.jafc.2c06359] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Protein structure affects allergenicity, and critical structural elements, especially conformational epitopes that determine allergenicity, have attracted a great deal of interest. In this study, we aimed to identify the localized structure that affects the potential allergenicity of protein by making targeted modifications of Ara h 2 and comparing the structure and allergenicity of mutants with those of the wide-type allergen. The structures of the allergen and its mutants were characterized by circular dichroism and ultraviolet absorption spectroscopy and simulated by molecular dynamics. The allergenicity was assessed by Western blotting, an indirect competitive enzyme-linked immunosorbent assay, a cell model, and a mouse model. Then, the structures that affect allergenicity were analyzed and screened. Our results showed that mutations in amino acids changed the nearby localized structure and the overall structures. The structural changes affected the IgE binding capacity of the allergen and reduced its potential allergenicity. The solvent accessible surface area (SASA) of aromatic residues was positively correlated with the IgE binding capacity. The integrity of the disulfide bond is also critical for the binding of IgE to allergens. Interestingly, different mutations induced similar electrostatic potential and allergenicity changes, such as localized structure R62DPYSPSQDPYSPS75. In conclusion, the disulfide bond and the SASA of aromatic residues are important for the allergenicity of Ara h 2. The localized structure R62DPYSPSQDPYSPS75 is also crucial for the allergenicity of Ara h 2.
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Affiliation(s)
- Xiaoya Zhou
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Linmei Ren
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - 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
| | - Jie Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- Laboratory Animal Technology Center, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, 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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17
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Sztuk TKS, Rigby NM, Nørskov-Nielsen L, Koppelman SJ, Sancho AI, Knudsen NPH, Marsh J, Johnson P, Gupta S, Mackie AR, Larsen JM, Bøgh KL. Dose and route of administration determine the efficacy of prophylactic immunotherapy for peanut allergy in a Brown Norway rat model. Front Immunol 2023; 14:1121497. [PMID: 36911669 PMCID: PMC9996042 DOI: 10.3389/fimmu.2023.1121497] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 02/13/2023] [Indexed: 02/25/2023] Open
Abstract
Introduction Allergen-specific immunotherapy (IT) is emerging as a viable option for treatment of peanut allergy. Yet, prophylactic IT remains unexplored despite early introduction of peanut in infancy was shown to prevent allergy. There is a need to understand how allergens interact with the immune system depending on the route of administration, and how different dosages of allergen may protect from sensitisation and a clinical active allergy. Here we compared peanut allergen delivery via the oral, sublingual (SL), intragastric (IG) and subcutaneous (SC) routes for the prevention of peanut allergy in Brown Norway (BN) rats. Methods BN rats were administered PBS or three different doses of peanut protein extract (PPE) via either oral IT (OIT), SLIT, IGIT or SCIT followed by intraperitoneal (IP) injections of PPE to assess the protection from peanut sensitisation. The development of IgE and IgG1 responses to PPE and the major peanut allergens were evaluated by ELISAs. The clinical response to PPE was assessed by an ear swelling test (EST) and proliferation was assessed by stimulating splenocytes with PPE. Results Low and medium dose OIT (1 and 10 mg) and all doses of SCIT (1, 10, 100 µg) induced sensitisation to PPE, whereas high dose OIT (100 mg), SLIT (10, 100 or 1000 µg) or IGIT (1, 10 and 100 mg) did not. High dose OIT and SLIT as well as high and medium dose IGIT prevented sensitisation from the following IP injections of PPE and suppressed PPE-specific IgE levels in a dose-dependent manner. Hence, administration of peanut protein via different routes confers different risks for sensitisation and protection from peanut allergy development. Overall, the IgE levels toward the individual major peanut allergens followed the PPE-specific IgE levels. Discussion Collectively, this study showed that the preventive effect of allergen-specific IT is determined by the interplay between the specific site of PPE delivery for presentation to the immune system, and the allergen quantity, and that targeting and modulating tolerance mechanisms at specific mucosal sites may be a prophylactic strategy for prevention of peanut allergy.
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Affiliation(s)
| | - Neil Marcus Rigby
- School of Food Science & Nutrition, University of Leeds, Leeds, United Kingdom
| | | | - Stef J Koppelman
- Institute of Agriculture and Natural Resources, Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Ana Isabel Sancho
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
| | | | - Justin Marsh
- Institute of Agriculture and Natural Resources, Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Philip Johnson
- Institute of Agriculture and Natural Resources, Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE, United States
| | | | - Alan Robert Mackie
- School of Food Science & Nutrition, University of Leeds, Leeds, United Kingdom
| | - Jeppe Madura Larsen
- National Food Institute, Technical University of Denmark, Kgs. Lyngby, Denmark
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18
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Zhang Y, Bhardwaj SR, Vilches A, Breksa A, Lyu SC, Chinthrajah S, Nadeau KC, Jin T. IgE binding epitope mapping with TL1A tagged peptides. Mol Immunol 2023; 153:194-199. [PMID: 36527758 DOI: 10.1016/j.molimm.2022.12.001] [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: 09/28/2022] [Revised: 11/22/2022] [Accepted: 12/01/2022] [Indexed: 12/22/2022]
Abstract
Linear IgE epitopes play essential roles in persistent allergies, including peanut and tree nut allergies. Using chemically synthesized peptides attached to membranes and microarray experiments is one approach for determining predominant epitopes that has seen success. However, the overall expense of this approach and the inherent challenges in scaling up the production and purification of synthetic peptides precludes the general application of this approach. To overcome this problem, we have constructed a plasmid vector for expressing peptides sandwiched between an N-terminal His-tag and a trimeric protein. The vector was used to make overlapping peptides derived from peanut allergens Ara h 2. All the peptides were successfully expressed and purified. The resulting peptides were applied to identify IgE binding epitopes of Ara h 2 using four sera samples from individuals with known peanut allergies. New and previously defined dominant IgE binding epitopes of Ara h 2 were identified. This system may be readily applied to produce agents for component- and epitope-resolved food allergy diagnosis.
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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
| | - Ana Vilches
- US Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, CA 94710, USA
| | - Andrew Breksa
- 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
| | - Tengchuan Jin
- Hefei National Laboratory for Physical Sciences at Microscale, Laboratory of Structural Immunology, CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027 China.
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19
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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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Zhao X, Li G, Feng X, Cheng Q, Lu Z, Gu R, Lu J, Liu W. Physicochemical characterization and linear epitopes identification of arginine kinase allergen from Crassostrea gigas. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:3435-3445. [PMID: 34837649 DOI: 10.1002/jsfa.11691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 10/10/2021] [Accepted: 11/27/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Molluscan shellfish, including oysters, often cause allergic reactions in sensitive people throughout the world. It has been demonstrated that arginine kinase (AK) is one of the major allergens of oyster. The present study aimed to evaluate the immunoreactivity and structure of oyster AK as affected by heat treatment, pH change, and in vitro digestion. What is more, the immunoglobulin E-binding epitopes of this allergen were also predicted and validated. RESULTS Thermal and pH assays revealed that AK was unstable at temperature >40 °C or pH ≤5.0 by sodium dodecyl sulfate polyacrylamide gel electrophoresis and circular dichroism, and the digestibility assays suggested that AK was more easily digested by pepsin than by trypsin and chymotrypsin. The potential epitopes were predicted through immunoinformatics tools, and seven linear epitopes were identified by indirect competition enzyme-linked immunosorbent assay with pooled sera and individual serum from oyster-allergic patients. The critical amino acids in each epitope were also confirmed using mutant peptides. These linear epitopes and critical amino acids were apt to distribute on the outer surface of homology-based AK model. Moreover, the three denaturants (sodium dodecyl sulfate, β-mercaptoethanol, and urea) can destroy the spatial structure of AK and increase or reduce its allergenicity by denaturation treatments. CONCLUSION Processing conditions lay the foundation for the variation of allergenicity. Seven linear epitopes and their critical amino acids were identified by indirect competitive enzyme-linked immunosorbent assay. These findings will be helpful in allergy diagnosis and development of hypoallergenic products in the near future. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Xiaohan Zhao
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
| | - Guoming Li
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
| | - Xiaowen Feng
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
| | - Qingli Cheng
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
| | - Zhihao Lu
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
| | - Ruizeng Gu
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
| | - Jun Lu
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
| | - Wenying Liu
- Beijing Engineering Research Center of Protein & Functional Peptides, China National Research Institute of Food and Fermentation Industries, Beijing, PR China
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21
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Li WY, Cai ZL, Zhang BP, Chen JJ, Ji K. Identification of an immunodominant IgE epitope of Der p 39, a novel allergen of Dermatophagoides pteronyssinus. World Allergy Organ J 2022; 15:100651. [PMID: 35600837 PMCID: PMC9096144 DOI: 10.1016/j.waojou.2022.100651] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/11/2022] [Accepted: 04/12/2022] [Indexed: 11/16/2022] Open
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Hazebrouck S, Canon N, Dreskin SC. The Effector Function of Allergens. FRONTIERS IN ALLERGY 2022; 3:818732. [PMID: 35386644 PMCID: PMC8974742 DOI: 10.3389/falgy.2022.818732] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/14/2022] [Indexed: 01/29/2023] Open
Abstract
Allergens are antigens that generate an IgE response (sensitization) in susceptible individuals. The allergenicity of an allergen can be thought of in terms of its ability to sensitize as well as its ability to cross-link IgE/IgE receptor complexes on mast cells and basophils leading to release of preformed and newly formed mediators (effector activity). The identity of the allergens responsible for sensitization may be different from those that elicit an allergic response. Effector activity is determined by (1) the amount of specific IgE (sIgE) and in some circumstances the ratio of sIgE to total IgE, (2) the number of high affinity receptors for IgE (FcεR1) on the cell surface, (3) the affinity of binding of sIgE for its epitope and, in a polyclonal response, the collective avidity, (4) the number and spatial relationships of IgE binding epitopes on the allergen and (5) the presence of IgG that can bind to allergen and either block binding of sIgE and/or activate low affinity IgG receptors that activate intracellular inhibitory pathways. This review will discuss these important immunologic and physical properties that contribute to the effector activity of allergens.
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Affiliation(s)
- Stéphane Hazebrouck
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
| | - Nicole Canon
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO, United States
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO, United States
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24
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Suárez‐Fariñas M, Suprun M, Kearney P, Getts R, Grishina G, Hayward C, Luta D, Porter A, Witmer M, du Toit G, Lack G, Chinthrajah RS, Galli SJ, Nadeau K, Sampson HA. Accurate and reproducible diagnosis of peanut allergy using epitope mapping. Allergy 2021; 76:3789-3797. [PMID: 33991353 PMCID: PMC8607840 DOI: 10.1111/all.14905] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/19/2021] [Accepted: 04/25/2021] [Indexed: 01/18/2023]
Abstract
BACKGROUND Accurate diagnosis of peanut allergy is a significant clinical challenge. Here, a novel diagnostic blood test using the peanut bead-based epitope assay ("peanut BBEA") was developed utilizing the LEAP cohort and then validated using two independent cohorts. METHODS The development of the peanut BBEA diagnostic test followed the National Academy of Medicine's established guidelines with discovery performed on 133 subjects from the non-interventional arm of the LEAP trial and an independent validation performed on 82 subjects from the CoFAR2 and 84 subjects from the POISED study. All samples were analyzed using the peanut BBEA methodology, which measures levels of IgE to two Ara h 2 sequential (linear) epitopes and compares their combination to a threshold pre-specified in the model development phase. When a patient has an inconclusive outcome by skin prick testing (or sIgE), IgE antibody levels to this combination of two epitopes can distinguish whether the patient is "Allergic" or "Not Allergic." Diagnoses of peanut allergy in all subjects were confirmed by double-blind placebo-controlled food challenge and subjects' ages were 7-55 years. RESULTS In the validation using CoFAR2 and POISED cohorts, the peanut BBEA diagnostic test correctly diagnosed 93% of the subjects, with a sensitivity of 92%, specificity of 94%, a positive predictive value of 91%, and negative predictive value of 95%. CONCLUSIONS In validation of the peanut BBEA diagnostic test, the overall accuracy was found to be superior to existing diagnostic tests for peanut allergy including skin prick testing, peanut sIgE, and peanut component sIgE testing.
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Affiliation(s)
- Mayte Suárez‐Fariñas
- Department of Population Health Science and Policy and Department of Genetics and GenomicsIcahn School of MedicineNew YorkNYUSA
| | - Maria Suprun
- Department of Pediatrics, Allergy and ImmunologyIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Paul Kearney
- AllerGenis LLCHatfieldPAUSA
- Data Incites LLCSeattleWAUSA
| | | | - Galina Grishina
- Department of Pediatrics, Allergy and ImmunologyIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | | | | | | | | | | | | | | | - Stephen J. Galli
- Sean N. Parker Center for Allergy and Asthma ResearchStanford UniversityStanfordCAUSA
- Departments of Pathology and Microbiology & ImmunologyStanford UniversityStanfordCAUSA
| | - Kari Nadeau
- Sean N. Parker Center for Allergy and Asthma ResearchStanford UniversityStanfordCAUSA
| | - Hugh A. Sampson
- Department of Pediatrics, Allergy and ImmunologyIcahn School of Medicine at Mount SinaiNew YorkNYUSA
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25
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Üzülmez Ö, Kalic T, Mayr V, Lengger N, Tscheppe A, Radauer C, Hafner C, Hemmer W, Breiteneder H. The Major Peanut Allergen Ara h 2 Produced in Nicotiana benthamiana Contains Hydroxyprolines and Is a Viable Alternative to the E. Coli Product in Allergy Diagnosis. FRONTIERS IN PLANT SCIENCE 2021; 12:723363. [PMID: 34671372 PMCID: PMC8522509 DOI: 10.3389/fpls.2021.723363] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/17/2021] [Indexed: 05/12/2023]
Abstract
Peanut allergy is a potentially life-threatening disease that is mediated by allergen-specific immunoglobulin E (IgE) antibodies. The major peanut allergen Ara h 2, a 2S albumin seed storage protein, is one of the most dangerous and potent plant allergens. Ara h 2 is posttranslationally modified to harbor four disulfide bridges and three hydroxyprolines. These hydroxyproline residues are required for optimal IgE-binding to the DPYSPOHS motifs representing an immunodominant IgE epitope. So far, recombinant Ara h 2 has been produced in Escherichia coli, Lactococcus lactis, Trichoplusia ni insect cell, and Chlamydomonas reinhardtii chloroplast expression systems, which were all incapable of proline hydroxylation. However, molecular diagnosis of peanut allergy is performed using either natural or E. coli-produced major peanut allergens. As IgE from the majority of patients is directed to Ara h 2, it is of great importance that the recombinant Ara h 2 harbors all of its eukaryotic posttranslational modifications. We produced hydroxyproline-containing and correctly folded Ara h 2 in the endoplasmic reticulum of leaf cells of Nicotiana benthamiana plants, using the plant virus-based magnICON® transient expression system with a yield of 200 mg/kg fresh biomass. To compare prokaryotic with eukaryotic expression methods, Ara h 2 was expressed in E. coli together with the disulfide-bond isomerase DsbC and thus harbored disulfide bridges but no hydroxyprolines. The recombinant allergens from N. benthamiana and E. coli were characterized and compared to the natural Ara h 2 isolated from roasted peanuts. Natural Ara h 2 outperformed both recombinant proteins in IgE-binding and activation of basophils via IgE cross-linking, the latter indicating the potency of the allergen. Interestingly, significantly more efficient IgE cross-linking by the N. benthamiana-produced allergen was observed in comparison to the one induced by the E. coli product. Ara h 2 from N. benthamiana plants displayed a higher similarity to the natural allergen in terms of basophil activation due to the presence of hydroxyproline residues, supporting so far published data on their contribution to the immunodominant IgE epitope. Our study advocates the use of N. benthamiana plants instead of prokaryotic expression hosts for the production of the major peanut allergen Ara h 2.
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Affiliation(s)
- Öykü Üzülmez
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Tanja Kalic
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
- Department of Dermatology, University Hospital St. Pölten, Karl Landsteiner University of Health Sciences, St. Pölten, Austria
| | - Vanessa Mayr
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Nina Lengger
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Angelika Tscheppe
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Christian Radauer
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - Christine Hafner
- Department of Dermatology, University Hospital St. Pölten, Karl Landsteiner University of Health Sciences, St. Pölten, Austria
- Karl Landsteiner Institute for Dermatological Research, St. Pölten, Austria
| | | | - Heimo Breiteneder
- Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
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Fuhrmann V, Huang HJ, Akarsu A, Shilovskiy I, Elisyutina O, Khaitov M, van Hage M, Linhart B, Focke-Tejkl M, Valenta R, Sekerel BE. From Allergen Molecules to Molecular Immunotherapy of Nut Allergy: A Hard Nut to Crack. Front Immunol 2021; 12:742732. [PMID: 34630424 PMCID: PMC8496898 DOI: 10.3389/fimmu.2021.742732] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 08/23/2021] [Indexed: 12/02/2022] Open
Abstract
Peanuts and tree nuts are two of the most common elicitors of immunoglobulin E (IgE)-mediated food allergy. Nut allergy is frequently associated with systemic reactions and can lead to potentially life-threatening respiratory and circulatory symptoms. Furthermore, nut allergy usually persists throughout life. Whether sensitized patients exhibit severe and life-threatening reactions (e.g., anaphylaxis), mild and/or local reactions (e.g., pollen-food allergy syndrome) or no relevant symptoms depends much on IgE recognition of digestion-resistant class I food allergens, IgE cross-reactivity of class II food allergens with respiratory allergens and clinically not relevant plant-derived carbohydrate epitopes, respectively. Accordingly, molecular allergy diagnosis based on the measurement of allergen-specific IgE levels to allergen molecules provides important information in addition to provocation testing in the diagnosis of food allergy. Molecular allergy diagnosis helps identifying the genuinely sensitizing nuts, it determines IgE sensitization to class I and II food allergen molecules and hence provides a basis for personalized forms of treatment such as precise prescription of diet and allergen-specific immunotherapy (AIT). Currently available forms of nut-specific AIT are based only on allergen extracts, have been mainly developed for peanut but not for other nuts and, unlike AIT for respiratory allergies which utilize often subcutaneous administration, are given preferentially by the oral route. Here we review prevalence of allergy to peanut and tree nuts in different populations of the world, summarize knowledge regarding the involved nut allergen molecules and current AIT approaches for nut allergy. We argue that nut-specific AIT may benefit from molecular subcutaneous AIT (SCIT) approaches but identify also possible hurdles for such an approach and explain why molecular SCIT may be a hard nut to crack.
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Affiliation(s)
- Verena Fuhrmann
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Huey-Jy Huang
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Aysegul Akarsu
- Division of Allergy and Asthma, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Igor Shilovskiy
- Laboratory for Molecular Allergology, National Research Center (NRC) Institute of Immunology Federal Medical-Biological Agency (FMBA) of Russia, Moscow, Russia
| | - Olga Elisyutina
- Laboratory for Molecular Allergology, National Research Center (NRC) Institute of Immunology Federal Medical-Biological Agency (FMBA) of Russia, Moscow, Russia
| | - Musa Khaitov
- Laboratory for Molecular Allergology, National Research Center (NRC) Institute of Immunology Federal Medical-Biological Agency (FMBA) of Russia, Moscow, Russia
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Marianne van Hage
- Department of Medicine Solna, Division of Immunology and Allergy, Karolinska Institutet and Karolinska University, Hospital, Stockholm, Sweden
| | - Birgit Linhart
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Margarete Focke-Tejkl
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Rudolf Valenta
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- Laboratory for Molecular Allergology, National Research Center (NRC) Institute of Immunology Federal Medical-Biological Agency (FMBA) of Russia, Moscow, Russia
- Karl Landsteiner University of Health Sciences, Krems, Austria
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergology, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Bulent Enis Sekerel
- Division of Allergy and Asthma, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
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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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Suprun M, Sicherer SH, Wood RA, Jones SM, Leung DYM, Henning AK, Dawson P, Burks AW, Lindblad R, Getts R, Suárez-Fariñas M, Sampson HA. Early epitope-specific IgE antibodies are predictive of childhood peanut allergy. J Allergy Clin Immunol 2020; 146:1080-1088. [PMID: 32795587 PMCID: PMC8095129 DOI: 10.1016/j.jaci.2020.08.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 11/26/2022]
Abstract
BACKGROUND Peanut allergy is characterized by the development of IgE against peanut antigen. OBJECTIVE We sought to evaluate the evolution of epitope-specific (es)IgE and esIgG4 in a prospective cohort of high-risk infants to determine whether antibody profiles can predict peanut allergy after age 4 years. METHODS The end point was allergy status at age 4+ years; samples from 293 children were collected at age 3 to 15 months and 2 to 3 and 4+ years. Levels of specific (s)IgE and sIgG4 to peanut and component proteins, and 50 esIgE and esIgG4 were quantified. Changes were analyzed with mixed-effects models. Machine learning algorithms were developed to identify a combination of antigen- and epitope-specific antibodies that using 3- to 15-month or 2- to 3-year samples can predict allergy status at age 4+ years. RESULTS At age 4+ years, 38% of children were Tolerant or 14% had Possible, 8% Convincing, 24% Serologic, and 16% Confirmed allergy. At age 3 to 15 months, esIgE profiles were similar among groups, whereas marked increases were evident at age 2 and 4+ years only in Confirmed and Serologic groups. In contrast, peanut sIgE level was significantly lower in the Tolerant group at age 3 to 15 months, increased in Confirmed and Serologic groups but decreased in Convincing and Possibly Allergic groups over time. An algorithm combining esIgEs with peanut sIgE outperformed different clinically relevant IgE cutoffs, predicting allergy status on an "unseen" set of patients with area under the curves of 0.84 at age 3 to 15 months and 0.87 at age 2 to 3 years. CONCLUSIONS Early epitope-specific plus peanut-specific IgE is predictive of allergy status at age 4+ years.
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Affiliation(s)
- Maria Suprun
- Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - Robert A Wood
- Johns Hopkins University School of Medicine, Baltimore, Md
| | - Stacie M Jones
- University of Arkansas for Medical Sciences and Arkansas Children's Hospital, Little Rock, Ark
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Thouvenot B, Roitel O, Tomasina J, Hilselberger B, Richard C, Jacquenet S, Codreanu-Morel F, Morisset M, Kanny G, Beaudouin E, Delebarre-Sauvage C, Olivry T, Favrot C, Bihain BE. Transcriptional frameshifts contribute to protein allergenicity. J Clin Invest 2020; 130:5477-5492. [PMID: 32634131 PMCID: PMC7524509 DOI: 10.1172/jci126275] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 07/01/2020] [Indexed: 01/07/2023] Open
Abstract
Transcription infidelity (TI) is a mechanism that increases RNA and protein diversity. We found that single-base omissions (i.e., gaps) occurred at significantly higher rates in the RNA of highly allergenic legumes. Transcripts from peanut, soybean, sesame, and mite allergens contained a higher density of gaps than those of nonallergens. Allergen transcripts translate into proteins with a cationic carboxy terminus depleted in hydrophobic residues. In mice, recombinant TI variants of the peanut allergen Ara h 2, but not the canonical allergen itself, induced, without adjuvant, the production of anaphylactogenic specific IgE (sIgE), binding to linear epitopes on both canonical and TI segments of the TI variants. The removal of cationic proteins from bovine lactoserum markedly reduced its capacity to induce sIgE. In peanut-allergic children, the sIgE reactivity was directed toward both canonical and TI segments of Ara h 2 variants. We discovered 2 peanut allergens, which we believe to be previously unreported, because of their RNA-DNA divergence gap patterns and TI peptide amino acid composition. Finally, we showed that the sIgE of children with IgE-negative milk allergy targeted cationic proteins in lactoserum. We propose that it is not the canonical allergens, but their TI variants, that initiate sIgE isotype switching, while both canonical and TI variants elicit clinical allergic reactions.
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Affiliation(s)
| | | | | | | | | | | | - Françoise Codreanu-Morel
- Unité Nationale d’Immunologie et d’Allergologie, Centre Hospitalier de Luxembourg, Luxembourg, Luxembourg
| | - Martine Morisset
- Unité d’Allergologie, Département de Pneumologie, Centre Hospitalier Universitaire Angers, Angers, France
| | - Gisèle Kanny
- Service de Médecine Interne, Immunologie Clinique et Allergologie, Hôpitaux de Brabois, Centre Hospitalier Universitaire de Nancy, Vandœuvre-lès-Nancy, France
| | - Etienne Beaudouin
- Unité d’Allergologie, Centre Hospitalier Régional de Metz, Metz, France
| | - Christine Delebarre-Sauvage
- Allergology Center Saint-Vincent de Paul Hospital, Groupe Hospitalier de l’Institut Catholique de Lille, Lille, France
| | - Thierry Olivry
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Claude Favrot
- Clinic for Small Animal Internal Medicine, University of Zurich, Zurich, Switzerland
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30
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Krause T, Röckendorf N, Meckelein B, Sinnecker H, Schwager C, Möckel S, Jappe U, Frey A. IgE Epitope Profiling for Allergy Diagnosis and Therapy - Parallel Analysis of a Multitude of Potential Linear Epitopes Using a High Throughput Screening Platform. Front Immunol 2020; 11:565243. [PMID: 33117349 PMCID: PMC7561404 DOI: 10.3389/fimmu.2020.565243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 09/08/2020] [Indexed: 12/22/2022] Open
Abstract
Immunoglobulin E (IgE) is pivotal for manifestation and persistence of most immediate-type allergies and some asthma phenotypes. Consequently, IgE represents a crucial target for both, diagnostic purposes as well as therapeutic approaches. In fact, allergen-specific immunotherapy – aiming to re-route an IgE-based inflammatory response into an innocuous immune reaction against the allergen – is the only curative approach for IgE-mediated allergic diseases known so far. However, this requires the cognate allergen to be known. Unfortunately, even in well-characterized allergics or asthmatics, often just a small fraction of total IgE can be assigned to specific target allergens. To overcome this knowledge gap, we have devised an analytical platform for unbiased IgE target epitope detection. The system relies on chemically produced random peptide libraries immobilized on polystyrene beads (“one-bead-one-compound (OBOC) libraries”) capable to present millions of different peptide motifs simultaneously to immunoglobulins from biological samples. Beads binding IgE are highlighted with a fluorophore-labeled anti-IgE antibody allowing fluorescence-based detection and isolation of positives, which then can be characterized by peptide sequencing. Setting-up this platform required an elaborate optimization process including proper choice of background suppressants, secondary antibody and fluorophore label as well as incubation conditions. For optimal performance our procedure involves a sophisticated pre-adsorption step to eliminate beads that react nonspecifically with anti-IgE secondary antibodies. This step turned out to be important for minimizing detection of “false positive” motifs that otherwise would erroneously be classified as IgE epitopes. In validation studies we were able to retrieve artificial test-peptide beads spiked into our library by using IgE directed against those test-peptides at physiological concentrations (≤20 IU/ml of specific IgE), and disease-relevant bead-bound epitopes of the major peanut allergen Ara h 2 by screening with sera from peanut allergics. Thus, we established a platform with which one can find and validate new immunoglobulin targets using patient material which displays a largely unknown immunoglobulin repertoire.
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Affiliation(s)
- Thorsten Krause
- Division of Mucosal Immunology and Diagnostics, Priority Area Asthma and Allergy, Research Center Borstel, Borstel, Germany.,Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany
| | - Niels Röckendorf
- Division of Mucosal Immunology and Diagnostics, Priority Area Asthma and Allergy, Research Center Borstel, Borstel, Germany.,Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany
| | - Barbara Meckelein
- Division of Mucosal Immunology and Diagnostics, Priority Area Asthma and Allergy, Research Center Borstel, Borstel, Germany.,Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany
| | - Heike Sinnecker
- Division of Mucosal Immunology and Diagnostics, Priority Area Asthma and Allergy, Research Center Borstel, Borstel, Germany.,Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany
| | - Christian Schwager
- Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany.,Division of Clinical Molecular Allergology, Priority Area Asthma and Allergy, Research Center Borstel, Borstel, Germany
| | - Stefanie Möckel
- Flow Cytometry Core Facility, Institute of Molecular Biology, Mainz, Germany
| | - Uta Jappe
- Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany.,Division of Clinical Molecular Allergology, Priority Area Asthma and Allergy, Research Center Borstel, Borstel, Germany.,Interdisciplinary Allergy Outpatient Clinic, Department of Pneumology, University of Lübeck, Lübeck, Germany
| | - Andreas Frey
- Division of Mucosal Immunology and Diagnostics, Priority Area Asthma and Allergy, Research Center Borstel, Borstel, Germany.,Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany
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31
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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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32
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Pahlow Mose A, Mortz E, Stahl Skov P, Mortz CG, Eller E, Sprogøe U, Barington T, Bindslev‐Jensen C. The quest for ingested peanut protein in human serum. Allergy 2020; 75:1721-1729. [PMID: 31715004 DOI: 10.1111/all.14109] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 09/15/2019] [Accepted: 10/07/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND There is mounting evidence that systemic uptake of food allergens is key to triggering anaphylaxis. However, direct proof for this theory is still lacking. The purpose of this study was to quantify the absorption and to determine the absorption kinetics of immunoreactive peanut protein in relation to the allergic response in human. METHODS Quantitative protein assays including mass spectrometry, dot blots and Western blotting were developed to determine the level of Ara h 2 absorption in human serum. The double monoclonal sandwich ELISA was applied to quantify absorbed Ara h 2 and 6, and the basophil histamine release assay and the human passive cutaneous anaphylaxis test were utilized to study the absorption kinetics of immunologically intact peanut proteins. RESULTS The protein assays worked but were not sensitive enough to trace the minute amounts of absorbed Ara h 2 in human serum. The level of Ara h 6 in serum was found to be up to 0.2 ng/mL, but Ara h 2 could not be detected with the ELISA. Both the in vivo and the in vitro methods were successful in demonstrating that: immunoreactive peanut protein was absorbed shortly after ingestion (≤5 minutes); the peanut protein concentration peaks between 1 and 4 hours; and peanut proteins can circulate for at least 48 hours in the bloodstream. CONCLUSION Ingested peanut protein is absorbed systemically and retains its immunoreactive capacity in human serum. However, the precise quantities and the implication for the elicitation of anaphylaxis remains to be elucidated.
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Affiliation(s)
- Anja Pahlow Mose
- Odense Research Center for Anaphylaxis (ORCA) Odense University Hospital Odense Denmark
- Department of Dermatology and Allergy Center Odense University Hospital Odense Denmark
| | | | - Per Stahl Skov
- Odense Research Center for Anaphylaxis (ORCA) Odense University Hospital Odense Denmark
- RefLab Aps. Copenhagen Denmark
| | - Charlotte Gotthard Mortz
- Odense Research Center for Anaphylaxis (ORCA) Odense University Hospital Odense Denmark
- Department of Dermatology and Allergy Center Odense University Hospital Odense Denmark
| | - Esben Eller
- Odense Research Center for Anaphylaxis (ORCA) Odense University Hospital Odense Denmark
- Department of Dermatology and Allergy Center Odense University Hospital Odense Denmark
| | - Ulrik Sprogøe
- Department of Clinical Immunology Odense University Hospital Odense Denmark
| | - Torben Barington
- Department of Clinical Immunology Odense University Hospital Odense Denmark
| | - Carsten Bindslev‐Jensen
- Odense Research Center for Anaphylaxis (ORCA) Odense University Hospital Odense Denmark
- Department of Dermatology and Allergy Center Odense University Hospital Odense Denmark
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Evaluating the potential allergenicity of dietary proteins using model strong to non-allergenic proteins in germ-free mice. Food Chem Toxicol 2020; 141:111398. [PMID: 32437892 DOI: 10.1016/j.fct.2020.111398] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 11/22/2022]
Abstract
Currently no validated animal model is predictive of human responses in ranking purified dietary proteins in the prevalence or potency of food allergy in humans. Since the gastrointestinal microbiota is thought to influence oral tolerance, we hypothesize that a germ-free mouse model will more accurately predict atopic human responses than conventional mice. Germ-free C3H/HeN mice were immunized with 60 μg Ara h 2, BLG, or LOX by three weekly intraperitoneal (IP) injections with alum adjuvant. One week following the final immunization an IP challenge of 500 μg of Ara h 2, BLG, or LOX was administered. Thirty minutes post-challenge clinical scores were graded and body temperatures recorded. The presence of protein-specific IgE and mast cell protease concentrations in mouse sera were determined using ELISA. Upon challenge germ-free mice sensitized with Ara h 2 and BLG exhibited significantly more severe clinical scores compared to germ-free mice immunized with LOX. Hypothermic responses in challenged mice differed between the three proteins post-challenge. Results indicate that this model can differentiate between potent and non-allergens based on temperature drop, clinical scores, and biomarkers. Additional proteins with known human exposure and allergenicity are needed to confirm the predictive accuracy.
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34
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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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35
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Novel Bead-Based Epitope Assay is a sensitive and reliable tool for profiling epitope-specific antibody repertoire in food allergy. Sci Rep 2019; 9:18425. [PMID: 31804555 PMCID: PMC6895130 DOI: 10.1038/s41598-019-54868-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 11/09/2019] [Indexed: 12/16/2022] Open
Abstract
Identification of allergenic IgE epitopes is instrumental for the development of novel diagnostic and prognostic methods in food allergy. In this work, we present the quantification and validation of a Bead-Based Epitope Assay (BBEA) that through multiplexing of epitopes and multiple sample processing enables completion of large experiments in a short period of time, using minimal quantities of patients’ blood. Peptides that are uniquely coupled to beads are incubated with serum or plasma samples, and after a secondary fluorophore-labeled antibody is added, the level of fluorescence is quantified with a Luminex reader. The signal is then normalized and converted to epitope-specific antibody binding values. We show that the effect of technical artifacts, i.e. well position or reading order, is minimal; and batch effects - different individual microplate runs - can be easily estimated and eliminated from the data. Epitope-specific antibody binding quantified with BBEA is highly reliable, reproducible and has greater sensitivity of epitope detection compared to peptide microarrays. IgE directed at allergenic epitopes is a sensitive biomarker of food allergy and can be used to predict allergy severity and phenotypes; and quantification of the relationship between epitope-specific IgE and IgG4 can further improve our understanding of the immune mechanisms behind allergic sensitization.
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36
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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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37
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38
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Ehlers AM, Klinge M, Suer W, Weimann Y, Knulst AC, Besa F, Le TM, Otten HG. Ara h 7 isoforms share many linear epitopes: Are 3D epitopes crucial to elucidate divergent abilities? Clin Exp Allergy 2019; 49:1512-1519. [PMID: 31520442 PMCID: PMC6900131 DOI: 10.1111/cea.13496] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/16/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
Abstract
Background The peanut allergens Ara h 2, h 6, and h 7 are potent allergens and can trigger severe reactions. Ara h 7 consists of three isoforms differing in their ability to induce basophil degranulation, whereas the ability of Ara h 7.0201 is comparable to Ara h 2 and 6 as shown in previous literature. Objective To identify linear epitopes of Ara h 7.0101, Ara h 7.0201 and Ara h 7.0301 recognized by IgE and IgG4 from patients sensitized to Ara h 7 and to investigate their potential to elucidate divergent abilities of the Ara h 7 isoforms in inducing basophil activation. Methods Linear epitopes recognized by IgE and IgG4 were mapped by peptide microarray analysis containing 15‐mer peptides of Ara h 2.0201, 6, 7.0101, 7.0201 and 7.0301 and 39 peanut allergic patients sensitized to Ara h 7 (discovery). For validation, 20‐mer peptides containing the minimal epitope and surrounding amino acids were incubated with 25 sensitized patients and 10 controls (validation). Results Three out of 14 linear epitopes were unique for each isoform (Ara h 7.0101: aa 97‐109; Ara h 7.0201: aa 122‐133; Ara h 7.0301: aa 65‐74) but scarcely recognized by IgE. The main linear IgE epitope (aa 51‐57) located in the long flexible loop of all Ara h 7 isoforms was bound by antibodies from 31% of the patients (discovery and validation cohort). Regarding IgG4, 55% of the patients recognized an epitope present on all isoforms (aa 55‐65), whereas epitope aa 129‐137, only present on Ara h 7.0101/0.0301, was recognized by 38% of the patients. Recognition was highly individual, although 20% of the patients recognized any linear epitope neither by IgE nor by IgG4 despite a low mean z‐score of ≥ 1.7. Remarkably, only 50% of the patients recognized one or more epitopes by IgE. Conclusion & Clinical Relevance Ara h 7 isoforms share many linear epitopes being easily accessible for antibody binding. Unique epitopes, essential to elucidate divergent potencies, were scarcely recognized, suggesting a crucial involvement of conformational epitopes.
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Affiliation(s)
- Anna M Ehlers
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | | | | | - André C Knulst
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Thuy-My Le
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Henny G Otten
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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39
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Cai ZL, Zhang Z, Luo WL, Hou YB, He YS, Chen JJ, Ji K. Identification of immunodominant IgE epitopes of the major house dust mite allergen Der f 24. Int J Mol Med 2019; 44:1888-1898. [PMID: 31545417 PMCID: PMC6777665 DOI: 10.3892/ijmm.2019.4345] [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: 06/05/2019] [Accepted: 08/16/2019] [Indexed: 11/17/2022] Open
Abstract
Previously, a ubiquinol-cytochrome c reductase binding protein (UQCRB) homolog was identified in the house dust mite (HDM) species Dermatophagoides farinae (Der f) as a major allergen. In the present study, the immunodominant immunoglobulin E (IgE) epitope of the protein Der f 24 was investigated. Analysis of the homologous amino acid (aa) sequences in Der f and human UQCRB was performed. Four different recombinant Der f 24 and hybrid proteins formed by integrating Der f and human UQCRB sequences were expressed in Escherichia coli, purified using Ni-NTA resins, and IgE-binding activity was determined using IgE-western blotting and enzyme-linked immunosorbent assay (ELISA) experiments. IgE epitopes were further identified by IgE-dot blotting and IgE-ELISA with synthetic polypeptides and HDM-allergic sera. Three-dimensional (3D) structural modeling was used to analyze the position of the immuno-dominant IgE epitope. The amino acid sequence homology between Der f 24 and the human UQCRB protein was determined to be 39.34%. IgE-ELISA and western blot analysis showed that all of the Der f-human UQCRB hybrid proteins generated, except for the one lacking 59 residues of the N-terminal region of Der f 24, were bound by allergic serum IgE. A synthetic polypeptide consisting of 32 residues of the N-terminal reacted with IgEs from HDM-allergic sera and could be used to generate high titer specific IgG or specific IgE antibodies in immunized mice. The 32-aa N-terminal region of Der f 24 was localized to a structural protrusion, which may facilitate specific IgE-binding. These results indicate that the immunodominant IgE epitope of Der f 24 is located mainly in a 32-residue region of the N-terminus. These findings may inform the mechanisms of HDM allergy sensitization and allergy immunotherapy development.
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Affiliation(s)
- Ze-Lang Cai
- Department of Biochemistry and Molecular Biology, Health Science Center of Shenzhen University, Shenzhen, Guangdong 518060, P.R. China
| | - Zhen Zhang
- Department of Biochemistry and Molecular Biology, Health Science Center of Shenzhen University, Shenzhen, Guangdong 518060, P.R. China
| | - Wen-Li Luo
- Department of Biochemistry and Molecular Biology, Health Science Center of Shenzhen University, Shenzhen, Guangdong 518060, P.R. China
| | - Yi-Bo Hou
- Department of Biochemistry and Molecular Biology, Health Science Center of Shenzhen University, Shenzhen, Guangdong 518060, P.R. China
| | - Yong-Shen He
- Department of Biochemistry and Molecular Biology, Health Science Center of Shenzhen University, Shenzhen, Guangdong 518060, P.R. China
| | - Jia-Jie Chen
- Department of Biochemistry and Molecular Biology, Health Science Center of Shenzhen University, Shenzhen, Guangdong 518060, P.R. China
| | - Kunmei Ji
- Department of Biochemistry and Molecular Biology, Health Science Center of Shenzhen University, Shenzhen, Guangdong 518060, P.R. China
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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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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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42
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Zhang Y, Wu Z, Li K, Li X, Yang A, Tong P, Chen H. Allergenicity assessment on thermally processed peanut influenced by extraction and assessment methods. Food Chem 2019; 281:130-139. [DOI: 10.1016/j.foodchem.2018.12.070] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 12/04/2018] [Accepted: 12/13/2018] [Indexed: 02/03/2023]
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43
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Identification and mutational analysis of continuous, immunodominant epitopes of the major oyster allergen Crag 1. Clin Immunol 2019; 201:20-29. [PMID: 30807831 DOI: 10.1016/j.clim.2019.02.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 02/15/2019] [Accepted: 02/16/2019] [Indexed: 01/03/2023]
Abstract
Shellfish, including oysters, often cause allergic reactions in children and adults. Oysters are inevitably consumed because of its delicacy and nutritional benefit, leading to frequent occurrence of severe clinical symptoms observed in patients with oyster hypersensitivity. We aimed to identify the immunodominant epitopes of oyster tropomyosin and crucial amino acids for IgE binding, which will help us to further understand the immunochemical characteristics of Cra g 1. The potential epitopes were predicted by immunoinformatics tools and the resultant immunodominant epitopes were identified by inhibition ELISA with pooled sera and individual serum from oyster allergic patients. Surprisingly, homologous substitution of multiple amino acids led to obviously decrease affinity of IgE antibodies, but this manner did not abrogate binding completely. Five major linear epitopes were evenly distributed on the surface of homology-based Cra g 1 model and hydrophilic residues appeared to be the most important for IgE binding. These results not only offer a better understanding of the molecular mechanism of interaction between Cra g 1 and oyster-specific IgE but also have significance in clinical diagnosis and immunotherapy.
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44
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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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45
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Joo Chan C, Richardo T, Lim RLH. Current Trend in Immunotherapy for Peanut Allergy. Int Rev Immunol 2019; 37:279-290. [DOI: 10.1080/08830185.2018.1509967] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Chong Joo Chan
- Department of Biotechnology, Faculty of Applied Sciences, UCSI University, Cheras, Kuala Lumpur, Malaysia
| | - Timmy Richardo
- Department of Biomedicine, Indonesia International Institute for Life Sciences (i3L), Jakarta, Indonesia
| | - Renee Lay Hong Lim
- Department of Biotechnology, Faculty of Applied Sciences, UCSI University, Cheras, Kuala Lumpur, Malaysia
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46
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Ehlers AM, Blankestijn MA, Knulst AC, Klinge M, Otten HG. Can alternative epitope mapping approaches increase the impact of B-cell epitopes in food allergy diagnostics? Clin Exp Allergy 2018; 49:17-26. [PMID: 30294841 PMCID: PMC7380004 DOI: 10.1111/cea.13291] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 01/08/2023]
Abstract
In vitro allergy diagnostics are currently based on the detection of specific IgE binding on intact allergens or a mixture thereof. This approach has drawbacks as it may yield false‐negative and/or false‐positive results. Thus, we reviewed the impact of known B‐cell epitopes of food allergens to predict transience or persistence, tolerance or allergy and the severity of an allergic reaction and to examine new epitope mapping strategies meant to improve serum‐based allergy diagnostics. Recent epitope mapping approaches have been worthwhile in epitope identification and may increase the specificity of allergy diagnostics by using epitopes predominately recognized by allergic patients in some cases. However, these approaches did not lead to discrimination between clinically relevant and irrelevant epitopes so far, since the polyclonal serum IgE‐binding epitope spectrum seems to be too individual, independent of the disease status of the patients. New epitope mapping strategies are necessary to overcome these obstacles. The use of patient‐derived monoclonal antibodies instead of patient sera for functional characterization of clinically relevant and irrelevant epitope combinations, distinguished by their ability to induce degranulation, might be a promising approach to gain more insight into the allergic reaction and to improve serum‐based allergy diagnostics.
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Affiliation(s)
- Anna M Ehlers
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Mark A Blankestijn
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | - Andre C Knulst
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.,Department of Dermatology and Allergology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Henny G Otten
- Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
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47
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Chang X, Wu Z, Zhao R, Zhang Y, Li X, Yang A, Tong P, Chen H. Analysis on MTGase catalysed cross-linked products of Ara h 2: structure and immunoreactivity. FOOD AGR IMMUNOL 2018. [DOI: 10.1080/09540105.2018.1529739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- Xuejiao Chang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
- School of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, People’s Republic of China
| | - Ruifang Zhao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
| | - Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
- School of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, People’s Republic of China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, People’s Republic of China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, People’s Republic of China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, People’s Republic of China
- Sino-German Joint Research Institute, Nanchang University, Nanchang, People’s Republic of China
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48
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Peanut allergens: new consolidated findings on structure, characteristics, and allergome. Allergol Select 2018; 2:67-79. [PMID: 31826045 PMCID: PMC6881859 DOI: 10.5414/alx01418e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/29/2011] [Indexed: 11/18/2022] Open
Abstract
Immunoglobulin E-mediated food allergy is the result of a complex pathomechanism. Factors contributing to the dysfunction of the immune system are the allergenic sources and the variable matrix effects arising from the processes involved in interaction with the gastrointestinal tract, the allergens themselves through their structural features, and the specific behavior of the individual immune system. The starting point for elucidating the pathomechanism of food allergy is the identification of allergens and the description of their structure. They are the basis for in vitro diagnostics as well as the development of immunotherapeutic drugs. With regard to Class I food allergy, peanut allergy affects by far the largest group of patients. 11 allergens have been identified in peanuts. Ara h 1, Ara h 3, and Ara h 4 belong to the cupin superfamily, Ara h 2, Ara h 6, and Ara h 7 to the prolamin superfamily; Ara h 5 (profilins) and Ara h 8 (superfamily of Bet v 1-homologous proteins) are associated with aeroallergens. Peanut lipid transfer proteins (LTP) and two peanut oleosins are listed as Ara h 9, Ara h 10, and Ara h 11 by the IUIS Allergen Nomenclature Subcommittee. Peanut agglutinin (PNA) and a third oleosin have been shown to possess allergenic properties. The effect of the above specified allergens has to be considered in the context of their matrix, which is influenced by processing factors.
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49
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Liu GY, Mei XJ, Hu MJ, Yang Y, Liu M, Li MS, Zhang ML, Cao MJ, Liu GM. Analysis of the Allergenic Epitopes of Tropomyosin from Mud Crab Using Phage Display and Site-Directed Mutagenesis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:9127-9137. [PMID: 30107732 DOI: 10.1021/acs.jafc.8b03466] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Mud crab ( Scylla serrata), which is widely consumed, can cause severe allergic symptoms. Eight linear epitopes and seven conformational epitopes of tropomyosin (TM) from S. serrata were identified using phage display. The conformational epitopes were formed based on the coiled-coil structure of TM. Most of the epitopes were located in the regions where primary structures were conserved among crustacean TM. Twelve synthetic peptides were designed according to the epitopes and trypsin-cutting sites of TM, among them, three synthetic peptides (including one linear epitope and two conformational epitopes) were recognized by all of the patient sera using inhibitory dot blotting. A triple-variant (R90A-E164A-Y267A) was constructed based on the critical amino acids of the TM epitope. The IgE-binding activity of the triple-variant was significantly reduced compared with that of native TM. The results of phage display and site-directed mutagenesis offered new information regarding conformational epitopes of TM.
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Affiliation(s)
- Guang-Yu Liu
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
| | - Xue-Jiao Mei
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
| | - Meng-Jun Hu
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
| | - Yang Yang
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
| | - Meng Liu
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
| | - Meng-Si Li
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
| | - Ming-Li Zhang
- Xiamen Second Hospital , Xiamen , Fujian 361021 , China
| | - Min-Jie Cao
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
| | - Guang-Ming Liu
- College of Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources , Jimei University , Xiamen , Fujian China
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50
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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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