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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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2
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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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3
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Sun N, Liu Y, Liu K, Wang S, Liu Q, Lin S. Gastrointestinal fate of food allergens and its relationship with allergenicity. Compr Rev Food Sci Food Saf 2022; 21:3376-3404. [PMID: 35751399 DOI: 10.1111/1541-4337.12989] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/29/2022] [Accepted: 05/09/2022] [Indexed: 01/15/2023]
Abstract
Food allergens are closely related to their gastrointestinal digestion fate, but the changes in food allergens during digestion and related mechanisms are quite complicated. This review presents in detail digestion models for predicting allergenicity, the fates of food allergens in oral, gastric and duodenal digestion, and the applications of digestomics in mapping IgE-binding epitopes of digestion-resistant peptides. Moreover, this review highlights the structure-activity relationships of food allergens during gastrointestinal digestion. Digestion-labile allergens may share common structural characteristics, such as high flexibility, rendering them easier to be hydrolyzed into small fragments with decreased or eliminated allergenicity. In contrast, the presence of disulfide bonds, tightly wound α-helical structures, or hydrophobic domains in food allergens helps them resist gastrointestinal digestion, stabilizing IgE-binding epitopes, thus maintaining their sensitization. In rare cases, digestion leads to increased allergenicity due to exposure of new epitopes. Finally, the action of the food matrix and processing on the digestion and allergenicity of food allergens as well as the underlying mechanisms was overviewed. The food matrix can directly act on the allergen by forming complexes or new epitopes to affect its gastrointestinal digestibility and thereby alter its allergenicity or indirectly affect the allergenicity by competing for enzymatic cleavage or influencing gastrointestinal pH and microbial flora. Several processing techniques attenuate the allergenicity of food proteins by altering their conformation to improve susceptibility to degradation by digestive enzymes. Given the complexity of food components, the food itself rather than a single allergen should be used to obtain more accurate data for allergenicity assessment. PRACTICAL APPLICATION: The review article will help to understand the relationship between food protein digestion and allergenicity, and may provide fundamental information for evaluating and reducing the allergenicity of food proteins.
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Affiliation(s)
- Na Sun
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China.,Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, P. R. China
| | - Yao Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China
| | - Kexin Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China
| | - Shan Wang
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China
| | - Qiaozhen Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China.,Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, P. R. China
| | - Songyi Lin
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China.,Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, P. R. China
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4
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Suarez-Farinas M, Suprun M, Bahnson HT, Raghunathan R, Getts R, duToit G, Lack G, Sampson HA. Evolution of epitope-specific IgE and IgG 4 antibodies in children enrolled in the LEAP trial. J Allergy Clin Immunol 2021; 148:835-842. [PMID: 33592205 DOI: 10.1016/j.jaci.2021.01.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 12/15/2020] [Accepted: 01/15/2021] [Indexed: 01/28/2023]
Abstract
BACKGROUND In the LEAP (Learning Early About Peanut Allergy) trial, early consumption of peanut in high-risk infants was found to decrease the rate of peanut allergy at 5 years of age. Sequential epitope-specific (ses-)IgE is a promising biomarker of clinical peanut reactivity. OBJECTIVE We sought to compare the evolution of ses-IgE and ses-IgG4 in children who developed (or not) peanut allergy and to evaluate the immunomodulatory effects of early peanut consumption on these antibodies. METHODS Sera from 341 children (LEAP cohort) were assayed at baseline, 1, 2.5, and 5 years of age, with allergy status determined by oral food challenge at 5 years. A bead-based epitope assay was used to quantitate ses-IgE and ses-IgG4 to 64 sequential epitopes from Ara h 1 to Ara h 3 and was analyzed using linear mixed-effect models. RESULTS In children avoiding peanut who became peanut allergic, the bulk of peanut ses-IgE did not develop until after 2.5 years. Minimal increases of ses-IgE occurred after 1 year in consumers, but not to the same epitopes as those in children developing peanut allergy. No major changes in ses-IgE were seen in nonallergic or sensitized children. IgE in sensitized consumers was detected against peanut proteins. ses-IgG4 increased over time in most children regardless of consumption or allergy status. CONCLUSIONS Early peanut consumption in infants at high risk of developing peanut allergy appears to divert the immunologic response to a presumably "protective" effect. In general, consumers tend to generate ses-IgG4 earlier and in greater quantities than nonconsumers do, whereas only avoiders tend to generate significant quantities of ses-IgE.
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Affiliation(s)
- Mayte Suarez-Farinas
- Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY; Center for Biostatistics, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Maria Suprun
- Division of Pediatric Allergy and Immunology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Henry T Bahnson
- Benaroya Research Institute and the Immune Tolerance Network, Seattle, Wash
| | - Rohit Raghunathan
- Center for Biostatistics, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY
| | | | - George duToit
- Department of Pediatrics, St Thomas Hospital and King's College London, London, United Kingdom
| | - Gideon Lack
- Department of Pediatrics, St Thomas Hospital and King's College London, London, United Kingdom
| | - Hugh A Sampson
- Division of Pediatric Allergy and Immunology, Icahn School of Medicine at Mount Sinai, New York, NY.
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5
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6
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Di Stasio L, Tranquet O, Picariello G, Ferranti P, Morisset M, Denery-Papini S, Mamone G. Comparative analysis of eliciting capacity of raw and roasted peanuts: the role of gastrointestinal digestion. Food Res Int 2020; 127:108758. [DOI: 10.1016/j.foodres.2019.108758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 10/09/2019] [Accepted: 10/14/2019] [Indexed: 01/06/2023]
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7
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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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8
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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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9
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Prodic I, Stanic-Vucinic D, Apostolovic D, Mihailovic J, Radibratovic M, Radosavljevic J, Burazer L, Milcic M, Smiljanic K, van Hage M, Cirkovic Velickovic T. Influence of peanut matrix on stability of allergens in gastric-simulated digesta: 2S albumins are main contributors to the IgE reactivity of short digestion-resistant peptides. Clin Exp Allergy 2018; 48:731-740. [PMID: 29412488 DOI: 10.1111/cea.13113] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 12/22/2017] [Accepted: 01/09/2018] [Indexed: 01/20/2023]
Abstract
BACKGROUND Most food allergens sensitizing via the gastrointestinal tract are stable proteins that are resistant to pepsin digestion, in particular major peanut allergens, Ara h 2 and Ara h 6. Survival of their large fragments is essential for sensitizing capacity. However, the immunoreactive proteins/peptides to which the immune system of the gastrointestinal tract is exposed during digestion of peanut proteins are unknown. Particularly, the IgE reactivity of short digestion-resistant peptides (SDRPs; <10 kDa) released by gastric digestion under standardized and physiologically relevant in vitro conditions has not been investigated. OBJECTIVE The aim of this study was to investigate and identify digestion products of major peanut allergens and in particular to examine IgE reactivity of SDRPs released by pepsin digestion of whole peanut grains. METHODS Two-dimensional gel-based proteomics and shotgun peptidomics, immunoblotting with allergen-specific antibodies from peanut-sensitized patients, enzyme-linked immunosorbent inhibition assay and ImmunoCAP tests, including far ultraviolet-circular dichroism spectroscopy were used to identify and characterize peanut digesta. RESULTS Ara h 2 and Ara h 6 remained mostly intact, and SDRPs from Ara h 2 were more potent in inhibiting IgE binding than Ara h 1 and Ara 3. Ara h 1 and Ara h 3 exhibited sequential digestion into a series of digestion-resistant peptides with preserved allergenic capacity. A high number of identified SDRPs from Ara h 1, Ara h 2 and Ara h 3 were part of short continuous epitope sequences and possessed substantial allergenic potential. CONCLUSION AND CLINICAL RELEVANCE Peanut grain digestion by oral and gastric phase enzymes generates mixture of products, where the major peanut allergens remain intact and their digested peptides have preserved allergenic capacity highlighting their important roles in allergic reactions to peanut.
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Affiliation(s)
- I Prodic
- Faculty of Chemistry, Innovation Centre Ltd., Belgrade, Serbia
| | - D Stanic-Vucinic
- University of Belgrade - Faculty of Chemistry, Center of Excellence for Molecular Food Sciences, Belgrade, Serbia.,University of Belgrade - Faculty of Chemistry, Department of Biochemistry, Belgrade, Serbia
| | - D Apostolovic
- Department of Medicine Solna, Immunology and Allergy Unit, Karolinska Institute and University Hospital, Stockholm, Sweden
| | - J Mihailovic
- University of Belgrade - Faculty of Chemistry, Center of Excellence for Molecular Food Sciences, Belgrade, Serbia
| | - M Radibratovic
- Center for Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Belgrade, Serbia
| | - J Radosavljevic
- University of Belgrade - Faculty of Chemistry, Center of Excellence for Molecular Food Sciences, Belgrade, Serbia.,University of Belgrade - Faculty of Chemistry, Department of Biochemistry, Belgrade, Serbia
| | - L Burazer
- Department of Allergy, Institute of Immunology, Virology and Sera Production, Torlak, Belgrade, Serbia
| | - M Milcic
- University of Belgrade - Faculty of Chemistry, Department of Inorganic Chemistry, Belgrade, Serbia.,Ghent University Global Campus, Incheon, Korea
| | - K Smiljanic
- University of Belgrade - Faculty of Chemistry, Center of Excellence for Molecular Food Sciences, Belgrade, Serbia
| | - M van Hage
- Department of Medicine Solna, Immunology and Allergy Unit, Karolinska Institute and University Hospital, Stockholm, Sweden
| | - T Cirkovic Velickovic
- University of Belgrade - Faculty of Chemistry, Center of Excellence for Molecular Food Sciences, Belgrade, Serbia.,University of Belgrade - Faculty of Chemistry, Department of Biochemistry, Belgrade, Serbia.,Ghent University Global Campus, Incheon, Korea.,Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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10
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Li X, Yuan S, Huang M, Gao J, Wu Z, Tong P, Yang A, Chen H. Identification of IgE and IgG epitopes on native Bos d 4 allergen specific to allergic children. Food Funct 2018; 7:2996-3005. [PMID: 27273451 DOI: 10.1039/c6fo00416d] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alpha-lactalbumin (ALA) is one of the major allergens in cow's milk. However, research on its conformational epitopes has been relatively limited. In our study, specific antibodies against cow's milk ALA were purified from eight children by two-step affinity chromatography. Subsequently, mimotopes against IgG and IgE were biopanned from Ph.D.-12 and Ph.D.-C7C, respectively. Based on the mimotopes, linear epitopes were defined with the UniProt alignment tool. Conformational epitopes were computed using the Pepitope Server. Six IgE and seven IgG linear epitopes were identified. Meanwhile, five IgE and three IgG conformational epitopes were revealed with PyMOL. The results showed that common residues were identified in both IgE and IgG epitopes and some residues of the conformational epitopes were composed of linear epitopes on bovine α-lactalbumin. The results indicated that the data could be used for developing hypoallergenic dairy products on the basis of epitopes and providing a diagnostic tool for the assessment of patients who are allergic to cow's milk.
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Affiliation(s)
- Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R.China and School of Food Science & Technology, Nanchang University, Nanchang 330047, P.R.China
| | - Shuilin Yuan
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R.China and School of Food Science & Technology, Nanchang University, Nanchang 330047, P.R.China
| | - Meijia Huang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R.China and School of Food Science & Technology, Nanchang University, Nanchang 330047, P.R.China
| | - Jinyan Gao
- School of Food Science & Technology, Nanchang University, Nanchang 330047, P.R.China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R.China and Jiangxi-OAI Joint Research Institute, Nanchang University, Nanchang 330047, P.R.China.
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R.China and School of Food Science & Technology, Nanchang University, Nanchang 330047, P.R.China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R.China and Jiangxi-OAI Joint Research Institute, Nanchang University, Nanchang 330047, P.R.China.
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P.R.China and Jiangxi-OAI Joint Research Institute, Nanchang University, Nanchang 330047, P.R.China.
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11
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Chen X, Dreskin SC. Application of phage peptide display technology for the study of food allergen epitopes. Mol Nutr Food Res 2017; 61. [PMID: 27995755 DOI: 10.1002/mnfr.201600568] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 11/09/2016] [Accepted: 12/05/2016] [Indexed: 12/16/2022]
Abstract
Phage peptide display technology has been used to identify IgE-binding mimotopes (mimics of natural epitopes) that mimic conformational epitopes. This approach is effective in the characterization of those epitopes that are important for eliciting IgE-mediated allergic responses by food allergens and those that are responsible for cross-reactivity among allergenic food proteins. Application of this technology will increase our understanding of the mechanisms whereby food allergens elicit allergic reactions, will facilitate the discovery of diagnostic reagents and may lead to mimotope-based immunotherapy.
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Affiliation(s)
- Xueni Chen
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
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12
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Luzar J, Štrukelj B, Lunder M. Phage display peptide libraries in molecular allergology: from epitope mapping to mimotope-based immunotherapy. Allergy 2016; 71:1526-1532. [PMID: 27341497 DOI: 10.1111/all.12965] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2016] [Indexed: 01/07/2023]
Abstract
Identification of allergen epitopes is a key component in proper understanding of the pathogenesis of type I allergies, for understanding cross-reactivity and for the development of mimotope immunotherapeutics. Phage particles have garnered recognition in the field of molecular allergology due to their value not only in competitive immunoscreening of peptide libraries but also as immunogenic carriers of allergen mimotopes. They integrate epitope discovery technology and immunization functions into a single platform. This article provides an overview of allergen mimotopes identified through the phage display technique. We discuss the contribution of phage display peptide libraries in determining dominant B-cell epitopes of allergens, in developing mimotope immunotherapy, in understanding cross-reactivity, and in determining IgE epitope profiles of individual patients to improve diagnostics and individualize immunotherapy. We also discuss the advantages and pitfalls of the methodology used to identify and validate the mimotopes.
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Affiliation(s)
- J. Luzar
- Chair of Pharmaceutical Biology; Faculty of Pharmacy; University of Ljubljana; Ljubljana Slovenia
| | - B. Štrukelj
- Chair of Pharmaceutical Biology; Faculty of Pharmacy; University of Ljubljana; Ljubljana Slovenia
| | - M. Lunder
- Chair of Pharmaceutical Biology; Faculty of Pharmacy; University of Ljubljana; Ljubljana Slovenia
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Gregory JA, Shepley-McTaggart A, Umpierrez M, Hurlburt BK, Maleki SJ, Sampson HA, Mayfield SP, Berin MC. Immunotherapy using algal-produced Ara h 1 core domain suppresses peanut allergy in mice. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:1541-50. [PMID: 26801740 PMCID: PMC5066676 DOI: 10.1111/pbi.12515] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 05/26/2023]
Abstract
Peanut allergy is an IgE-mediated adverse reaction to a subset of proteins found in peanuts. Immunotherapy aims to desensitize allergic patients through repeated and escalating exposures for several months to years using extracts or flours. The complex mix of proteins and variability between preparations complicates immunotherapy studies. Moreover, peanut immunotherapy is associated with frequent negative side effects and patients are often at risk of allergic reactions once immunotherapy is discontinued. Allergen-specific approaches using recombinant proteins are an attractive alternative because they allow more precise dosing and the opportunity to engineer proteins with improved safety profiles. We tested whether Ara h 1 and Ara h 2, two major peanut allergens, could be produced using chloroplast of the unicellular eukaryotic alga, Chlamydomonas reinhardtii. C. reinhardtii is novel host for producing allergens that is genetically tractable, inexpensive and easy to grow, and is able to produce more complex proteins than bacterial hosts. Compared to the native proteins, algal-produced Ara h 1 core domain and Ara h 2 have a reduced affinity for IgE from peanut-allergic patients. We further found that immunotherapy using algal-produced Ara h 1 core domain confers protection from peanut-induced anaphylaxis in a murine model of peanut allergy.
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Affiliation(s)
- James A Gregory
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ariel Shepley-McTaggart
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Michelle Umpierrez
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Barry K Hurlburt
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA
| | - Soheila J Maleki
- U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA, USA
| | - Hugh A Sampson
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stephen P Mayfield
- Department of Biology, University of California San Diego, La Jolla, CA, USA
| | - M Cecilia Berin
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Chen X, Negi SS, Liao S, Gao V, Braun W, Dreskin SC. Conformational IgE epitopes of peanut allergens Ara h 2 and Ara h 6. Clin Exp Allergy 2016; 46:1120-1128. [PMID: 27238146 DOI: 10.1111/cea.12764] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/11/2016] [Accepted: 05/14/2016] [Indexed: 12/01/2022]
Abstract
BACKGROUND Cross-linking of IgE antibody by specific epitopes on the surface of mast cells is a prerequisite for triggering symptoms of peanut allergy. IgE epitopes are frequently categorized as linear or conformational epitopes. Although linear IgE-binding epitopes of peanut allergens have been defined, little is known about conformational IgE-binding epitopes. OBJECTIVE To identify clinically relevant conformational IgE epitopes of the two most important peanut allergens, Ara h 2 and Ara h 6, using phage peptide library. METHODS A phage 12mer peptide library was screened with allergen-specific IgE from 4 peanut-allergic patients. Binding of the mimotopes to IgE from a total of 29 peanut-allergic subjects was measured by ELISA. The mimotope sequences were mapped on the surface areas of Ara h 2 and Ara h 6 using EpiSearch. RESULTS Forty-one individual mimotopes were identified that specifically bind anti- Ara h 2/Ara h 6 IgE as well as rabbit anti-Ara h 2 and anti-Ara h 6 IgG. Sequence alignment showed that none of the mimotope sequences match a linear segment of the Ara h 2 or Ara h 6 sequences. EpiSearch analysis showed that all the mimotopes mapped to surface patches of Ara h 2 and Ara h 6. Eight of the mimotopes were recognized by more than 90% of the patients, suggesting immunodominance. Each patient had distinct IgE recognition patterns but the recognition frequency was not correlated to the concentration of peanut specific IgE or to clinical history. CONCLUSIONS The mimotopes identified in this study represent conformational epitopes. Identification of similar surface patches on Ara h 2 and Ara h 6 further underscores the similarities between these two potent allergens.
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Affiliation(s)
- Xueni Chen
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
| | - Surendra S Negi
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Sumei Liao
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
| | - Valerie Gao
- Molecular Cellular Developmental Biology, University of Colorado, Boulder, CO
| | - Werner Braun
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX 77555
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO
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Matsuo H, Yokooji T, Taogoshi T. Common food allergens and their IgE-binding epitopes. Allergol Int 2015; 64:332-43. [PMID: 26433529 DOI: 10.1016/j.alit.2015.06.009] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 06/18/2015] [Accepted: 06/23/2015] [Indexed: 12/26/2022] Open
Abstract
Food allergy is an adverse immune response to certain kinds of food. Although any food can cause allergic reactions, chicken egg, cow's milk, wheat, shellfish, fruit, and buckwheat account for 75% of food allergies in Japan. Allergen-specific immunoglobulin E (IgE) antibodies play a pivotal role in the development of food allergy. Recent advances in molecular biological techniques have enabled the efficient analysis of food allergens. As a result, many food allergens have been identified, and their molecular structure and IgE-binding epitopes have also been identified. Studies of allergens have demonstrated that IgE antibodies specific to allergen components and/or the peptide epitopes are good indicators for the identification of patients with food allergy, prediction of clinical severity and development of tolerance. In this review, we summarize our current knowledge regarding the allergens and IgE epitopes in the well-researched allergies to chicken egg, cow's milk, wheat, shrimp, and peanut.
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Affiliation(s)
- Hiroaki Matsuo
- Department of Pharmaceutical Services, Hiroshima University Hospital, Hiroshima, Japan.
| | - Tomoharu Yokooji
- Department of Pathophysiology and Therapeutics, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Takanori Taogoshi
- Department of Pharmaceutical Services, Hiroshima University Hospital, Hiroshima, Japan
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16
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Pru du 2S albumin or Pru du vicilin? Comput Biol Chem 2015; 56:30-2. [DOI: 10.1016/j.compbiolchem.2015.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/26/2015] [Accepted: 03/27/2015] [Indexed: 11/20/2022]
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17
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Madsen JL, Kroghsbo S, Madsen CB, Pozdnyakova I, Barkholt V, Bøgh KL. The impact of structural integrity and route of administration on the antibody specificity against three cow's milk allergens - a study in Brown Norway rats. Clin Transl Allergy 2014; 4:25. [PMID: 25206972 PMCID: PMC4158394 DOI: 10.1186/2045-7022-4-25] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 07/28/2014] [Indexed: 01/14/2023] Open
Abstract
Background Characterisation of the specific antibody response, including the epitope binding pattern, is an essential task for understanding the molecular mechanisms of food allergy. Examination of antibody formation in a controlled environment requires animal models. The purpose of this study was to examine the amount and types of antibodies raised against three cow’s milk allergens; β-lactoglobulin (BLG), α-lactalbumin (ALA) and β-casein upon oral or intraperitoneal (i.p.) administration. A special focus was given to the relative amount of antibodies raised against linear versus conformational epitopes. Methods Specific antibodies were raised in Brown Norway (BN) rats. BN rats were dosed either (1) i.p. with the purified native cow’s milk allergens or (2) orally with skimmed milk powder (SMP) alone or together with gluten, without the use of adjuvants. The allergens were denatured by reduction and alkylation, resulting in unfolding of the primary structure and a consequential loss of conformational epitopes. The specific IgG1 and IgE responses were analysed against both the native and denatured form of the three cow’s milk allergens, thus allowing examination of the relative amount of linear versus conformational epitopes. Results The inherent capacity to induce specific IgG1 and IgE antibodies were rather similar upon i.p. administration for the three cow’s milk allergens, with BLG = ALA > β-casein. Larger differences were found between the allergens upon oral administration, with BLG > ALA > β-casein. Co-administration of SMP and gluten had a great impact on the specific antibody response, resulting in a significant reduced amount of antibodies. Together results indicated that most antibodies were raised against conformational epitopes irrespectively of the administration route, though the relative proportions between linear and conformational epitopes differed remarkably between the allergens. Conclusions This study showed that the three-dimensional (3D) structure has a significant impact on the antibodies raised for both systemic and orally administered allergens. A remarkable difference in the antibody binding patterns against linear and conformational epitope was seen between the allergens, indicating that the structural characteristics of proteins may heavily affect the induced antibody response.
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Affiliation(s)
- Jeanette Lund Madsen
- Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark
| | - Stine Kroghsbo
- Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark
| | - Charlotte Bernhard Madsen
- Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark
| | - Irina Pozdnyakova
- NNF Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Vibeke Barkholt
- Department of Systems Biology, Enzyme and Protein Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Katrine Lindholm Bøgh
- Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark
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Meta-analysis of IgE-binding allergen epitopes. Clin Immunol 2014; 153:31-9. [DOI: 10.1016/j.clim.2014.03.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 03/19/2014] [Indexed: 12/11/2022]
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Bøgh K, Nielsen H, Eiwegger T, Madsen C, Mills E, Rigby N, Szépfalusi Z, Roggen E. IgE versus IgG4 epitopes of the peanut allergen Ara h 1 in patients with severe allergy. Mol Immunol 2014; 58:169-76. [DOI: 10.1016/j.molimm.2013.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 11/21/2013] [Indexed: 10/25/2022]
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Khan IJ, Di R, Patel P, Nanda V. Evaluating pH-induced gastrointestinal aggregation of Arachis hypogaea 1 fragments as potential components of peanut allergy. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:8430-8435. [PMID: 23926999 PMCID: PMC4074858 DOI: 10.1021/jf401701t] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The seed storage glycoprotein Arachis hypogaea (Ara h) 1 is a major allergen found in peanuts. The biochemical resistance of food proteins to protease digestion contributes to their allergenicity. The rapid proteolysis of Ara h 1 under gastric conditions challenges this model. Biophysical and in vitro digestion experiments were carried out to identify how Ara h 1 epitopes might survive digestion, despite their facile degradation. The bicupin core of Ara h 1 can be unfolded at low pH and reversibly folded at higher pH. Additionally, peptide fragments from simulated gastric digestion predominantly form noncovalent aggregates when transferred to base. Disulfide cross-links within these aggregates occur as intermediates in relatively low amounts only at early times and play no role in shielding peptides from degradation. It is proposed that peptide fragments which survive gastric conditions form large aggregates in basic environments such as the small intestine, making epitopes available for triggering an allergic response.
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Affiliation(s)
- I. John Khan
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 679 Hoes Lane, Piscataway, NJ 08854, USA
| | - Rong Di
- Department of Plant Biology and Pathology, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ 08901, USA
| | - Priyesh Patel
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 679 Hoes Lane, Piscataway, NJ 08854, USA
| | - Vikas Nanda
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 679 Hoes Lane, Piscataway, NJ 08854, USA
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Bøgh KL, Barkholt V, Madsen CB. The sensitising capacity of intact β-lactoglobulin is reduced by co-administration with digested β-lactoglobulin. Int Arch Allergy Immunol 2012; 161:21-36. [PMID: 23257607 DOI: 10.1159/000343042] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 08/27/2012] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND It is generally believed that protein hydrolysis in the gastrointestinal tract decreases the allergenicity of food allergens. However, it remains unknown if specific properties of digestion products determine whether a sensitisation or tolerogenic immune response will develop. We sought to examine the sensitising capacity of the cow's milk allergen β-lactoglobulin (BLG) and digestion products thereof in a Brown Norway (BN) rat model. METHODS Intact BLG was digested in an in vitro model simulating the gastro-duodenal digestion process and subsequently fractionated by gel permeation chromatography. BN rats were dosed with either PBS, 200 µg of intact BLG, 30 µg of intact BLG, 200 µg of partially digested BLG, 200 µg of digested BLG, or with 200 µg of a fraction of large complexes or a fraction of small complexes. Sera from BN rats were analysed for specific antibodies and avidity was measured. RESULTS BLG partly resisted the digestion process. However, the BLG molecules that did not survive the digestion process were rapidly broken down to peptides of sizes less than Mr 4,500. Specific antibody responses revealed that both 200 and 30 µg of intact BLG had immunogenic as well as sensitising capacity, while digested BLG could not induce any specific antibodies. Most importantly, while intact BLG showed a significant sensitising capacity when administered alone, this sensitising capacity was significantly reduced when co-administered with digested BLG. CONCLUSIONS Co-immunisation of intact BLG with digested BLG reduces the sensitising capacity of intact BLG, which could result from tolerogenic mechanisms induced by the digestion products.
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Affiliation(s)
- Katrine Lindholm Bøgh
- National Food Institute, Division of Toxicology and Risk Assessment, Technical University of Denmark, Søborg, Denmark.
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Sirvent S, Akotenou M, Cuesta-Herranz J, Vereda A, Rodríguez R, Villalba M, Palomares O. The 11S globulin Sin a 2 from yellow mustard seeds shows IgE cross-reactivity with homologous counterparts from tree nuts and peanut. Clin Transl Allergy 2012; 2:23. [PMID: 23231956 PMCID: PMC3583068 DOI: 10.1186/2045-7022-2-23] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 12/07/2012] [Indexed: 02/03/2023] Open
Abstract
Background The 11S globulin Sin a 2 is a marker to predict severity of symptoms in mustard allergic patients. The potential implication of Sin a 2 in cross-reactivity with tree nuts and peanut has not been investigated so far. In this work, we studied at the IgG and IgE level the involvement of the 11S globulin Sin a 2 in cross-reactivity among mustard, tree nuts and peanut. Methods Eleven well-characterized mustard-allergic patients sensitized to Sin a 2 were included in the study. A specific anti-Sin a 2 serum was obtained in rabbit. Skin prick tests (SPT), enzyme-linked immunosorbent assay (ELISA), immunoblotting and IgG or IgE-inhibition immunoblotting experiments using purified Sin a 2, Sin a 1, Sin a 3, mustard, almond, hazelnut, pistachio, walnut or peanut extracts were performed. Results The rabbit anti-Sin a 2 serum showed high affinity and specificity to Sin a 2, which allowed us to demonstrate that Sin a 2 shares IgG epitopes with allergenic 11S globulins from tree nuts (almond, hazelnut, pistachio and walnut) but not from peanut. All the patients included in the study had positive skin prick test to tree nuts and/or peanut and we subdivided them into two different groups according to their clinical symptoms after ingestion of such allergenic sources. We showed that 11S globulins contain conserved IgE epitopes involved in cross-reactivity among mustard, tree nuts and peanut as well as species-specific IgE epitopes. Conclusions The allergenic 11S globulin Sin a 2 from mustard is involved in cross-reactivity at the IgE level with tree nuts and peanut. Although the clinical relevance of the cross-reactive IgE epitopes present in 11S globulins needs to be investigated in further detail, our results contribute to improve the diagnosis and management of mustard allergic patients sensitized to Sin a 2.
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Affiliation(s)
- Sofía Sirvent
- Department of Biochemistry and Molecular Biology, School of Chemistry, Complutense University of Madrid, Madrid, 28040, Spain.
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