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Mattar H, Padfield P, Simpson A, Mills ENC. The impact of a baked muffin matrix on the bioaccessibility and IgE reactivity of egg and peanut allergens. Food Chem 2021; 362:129879. [PMID: 34118511 DOI: 10.1016/j.foodchem.2021.129879] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/22/2021] [Accepted: 04/09/2021] [Indexed: 11/20/2022]
Abstract
Baked matrices, such as muffin, may help to promote tolerance to food allergens by modifying allergen structure, digestibility, and capacity to stimulate the immune responses. However, the impact of the muffin matrix on the bioaccessibility of allergens in the gastrointestinal tract is not well understood. Muffin containing egg and peanut was subjected to in vitro oral-gastro-duodenal digestion. During gastric digestion, the majority of the egg allergen Gal d 2 and the peanut allergens Ara h 1 and 3 were not bioaccessible. Subsequent duodenal digestion increased allergen bioaccessibility with Gal d 2 and the peanut allergen Ara h 2 proving highly resistant to digestion. The IgE reactivity of bioaccessible peanut allergens was retained to a greater extent than that of egg allergens after oral-gastric digestion. The starch and gluten-rich muffin matrix modifies allergen bioaccessiblity in a manner more similar to baked matrices such as bread, than low water activity matrices such as cookies.
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Affiliation(s)
- Hadeer Mattar
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK
| | - Phil Padfield
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK
| | - Angela Simpson
- School of Biological Sciences, Manchester Academic Health Sciences Centre, Wythenshawe Hospital Manchester University NHS Foundation Trust, M23 9LT Manchester, UK
| | - E N Clare Mills
- Division of Infection, Immunity and Respiratory Medicine, Manchester Academic Health Sciences Centre, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK.
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Smits M, Nooijen I, Redegeld F, de Jong A, Le TM, Knulst A, Houben G, Verhoeckx K. Digestion and Transport across the Intestinal Epithelium Affects the Allergenicity of Ara h 1 and 3 but Not of Ara h 2 and 6. Mol Nutr Food Res 2021; 65:e2000712. [PMID: 33434390 PMCID: PMC8047886 DOI: 10.1002/mnfr.202000712] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/04/2020] [Indexed: 12/12/2022]
Abstract
Scope No accepted and validated methods are currently available which can accurately predict protein allergenicity. In this study, the role of digestion and transport on protein allergenicity is investigated. Methods and results Peanut allergens (Ara h 1, 2, 3, and 6) and a milk allergen (β‐lactoglobulin) are transported across pig intestinal epithelium using the InTESTine model and afterward basophil activation is measured to assess the (remaining) functional properties. Additionally, allergens are digested by pepsin prior to epithelial transport and their allergenicity is assessed in a human mast cell activation assay. Remarkably, transported Ara h 1 and 3 are not able to activate basophils, in contrast to Ara h 2 and 6. Digestion prior to transport results in a significant increase in mast cell activation of Ara h 1 and 3 dependent on the length of digestion time. Activation of mast cells by Ara h 2 and 6 is unaffected by digestion prior to transport. Conclusions Digestion and transport influences the allergenicity of Ara h 1 and 3, but not of Ara h 2 and 6. The influence of digestion and transport on protein allergenicity may explain why current in vitro assays are not predictive for allergenicity.
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Affiliation(s)
- Mark Smits
- The Netherlands Organisation for Applied Scientific Research TNO, Princetonlaan 6, Utrecht, Utrecht, 3584 CB, The Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands.,Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Irene Nooijen
- The Netherlands Organisation for Applied Scientific Research TNO, Utrechtseweg 48, Zeist, Utrecht, 3704 HE, The Netherlands
| | - Frank Redegeld
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Universiteitsweg 99, Utrecht, Utrecht, 3584 CG, The Netherlands
| | - Aard de Jong
- Wageningen Food & Biobased Research, Bornse Weilanden 9, Wageningen, Gelderland, 6708 WG, The Netherlands.,The Netherlands Organisation for Applied Scientific Research TNO, Utrechtseweg 48, Zeist, Utrecht, 3704 HE, The Netherlands
| | - Thuy-My Le
- Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands.,Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands
| | - André Knulst
- Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands.,Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Geert Houben
- The Netherlands Organisation for Applied Scientific Research TNO, Princetonlaan 6, Utrecht, Utrecht, 3584 CB, The Netherlands.,Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands.,Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands
| | - Kitty Verhoeckx
- Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands.,Center for Translational Immunology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, Utrecht, Utrecht, 3584 CX, The Netherlands.,The Netherlands Organisation for Applied Scientific Research TNO, Utrechtseweg 48, Zeist, Utrecht, 3704 HE, The Netherlands
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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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James JK, Pike DH, Khan IJ, Nanda V. Structural and Dynamic Properties of Allergen and Non-Allergen Forms of Tropomyosin. Structure 2018; 26:997-1006.e5. [PMID: 29887498 PMCID: PMC6697176 DOI: 10.1016/j.str.2018.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 03/28/2018] [Accepted: 05/08/2018] [Indexed: 11/26/2022]
Abstract
To what extent do structural and biophysical features of food allergen proteins distinguish them from other proteins in our diet? Invertebrate tropomyosins (Tpms) as a class are considered "pan-allergens," inducing food allergy to shellfish and respiratory allergy to dust mites. Vertebrate Tpms are not known to elicit allergy or cross-reactivity, despite their high structural similarity and sequence identity to invertebrate homologs. We expect allergens are sufficiently stable against gastrointestinal proteases to survive for immune sensitization in the intestines, and that proteolytic stability will correlate with thermodynamic stability. Thermal denaturation of shrimp Tpm shows that it is more stable than non-allergen vertebrate Tpm. Shrimp Tpm is also more resistant to digestion. Molecular dynamics uncover local dynamics that select epitopes and global differences in flexibility between shrimp and pig Tpm that discriminate allergens from non-allergens. Molecular determinants of allergenicity depend not only on sequence but on contributions of protein structure and dynamics.
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Affiliation(s)
- Jose K James
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Douglas H Pike
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - I John Khan
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA
| | - Vikas Nanda
- Center for Advanced Biotechnology and Medicine, Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA.
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