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Koppelman SJ, de Jong GAH, Marsh J, Johnson P, Dowell E, Perusko M, Westphal A, van Hage M, Baumert J, Apostolovic D. Novel post-translationally cleaved Ara h 2 proteoforms: Purification, characterization and IgE-binding properties. Int J Biol Macromol 2024; 264:130613. [PMID: 38447836 DOI: 10.1016/j.ijbiomac.2024.130613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/01/2024] [Accepted: 03/02/2024] [Indexed: 03/08/2024]
Abstract
The 2S albumins Ara h 2 and Ara h 6 have been shown to be the most important source of allergenicity in peanut. Several isoforms of these allergens have been described. Using extraction and liquid chromatography we isolated proteins with homology to Ara h 2 and characterized hitherto unknown Ara h 2 proteoforms with additional post-translational cleavage. High-resolution mass spectrometry located the cleavage site on the non-structured loop of Ara h 2 while far UV CD spectroscopy showed a comparable structure to Ara h 2. The cleaved forms of Ara h 2 were present in genotypes of peanut commonly consumed. Importantly, we revealed that newly identified Ara h 2 cleaved proteoforms showed comparable IgE-binding using sera from 28 peanut-sensitized individuals, possessed almost the same IgE binding potency and are likely similarly allergenic as intact Ara h 2. This makes these newly identified forms relevant proteoforms of peanut allergen Ara h 2.
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Affiliation(s)
- Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | | | - Justin Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Emily Dowell
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Marija Perusko
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Adrie Westphal
- Wageningen University and Research (WUR), Wageningen, the Netherlands
| | - Marianne van Hage
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Joseph Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Danijela Apostolovic
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
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Jansen FAC, van Norren K, Baumert JL, van den Bos A, Jacobs JFM, Koppelman SJ. Peanut allergen Ara h 6 is detectable in blood transfusion products. Clin Transl Allergy 2023; 13:e12307. [PMID: 38006385 PMCID: PMC10624233 DOI: 10.1002/clt2.12307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023] Open
Affiliation(s)
| | | | | | - Annegeet van den Bos
- Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
| | - Joannes F. M. Jacobs
- Department of Laboratory MedicineRadboud University Medical CenterNijmegenThe Netherlands
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Marsh JT, Palmer LK, Koppelman SJ, Johnson PE. Determination of Allergen Levels, Isoforms, and Their Hydroxyproline Modifications Among Peanut Genotypes by Mass Spectrometry. Front Allergy 2022; 3:872714. [PMID: 35769555 PMCID: PMC9234871 DOI: 10.3389/falgy.2022.872714] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
The recently published reference genome of peanuts enables a detailed molecular description of the allergenic proteins of the seed. We used LC-MS/MS to investigate peanuts of different genotypes to assess variability and to better describe naturally occurring allergens and isoforms. Using relative quantification by mass spectrometry, minor variation of some allergenic proteins was observed, but total levels of Ara h 1, 2, 3, and 6 were relatively consistent among 20 genotypes. Previously published RP-HPLC methodology was used for comparison. The abundance of three Ara h 3 isoforms were variable among the genotypes and contributed to a large proportion of total Ara h 3 where present. Previously unpublished hydroxyproline sites were identified in Ara h 1 and 3. Hydroxylation did not vary significantly where sites were present. Peanut allergen composition was largely stable, with only some isoforms displaying differences between genotypes. The resulting differences in allergenicity are of unknown clinical significance but are likely to be minor. The data presented herein allow for the design of targeted MS methodology to allow the quantitation and therefore control of peanut allergens of clinical relevance and observed variability.
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Miller TA, Koppelman SJ, Bird JA, Hernandez-Trujillo V, Thyagarajan A, Mack D, Chalil JM, Green TD, Baumert JL. Peanut cross-contamination in randomly selected baked goods. Ann Allergy Asthma Immunol 2022; 128:439-442. [PMID: 35131409 DOI: 10.1016/j.anai.2022.01.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/14/2022] [Accepted: 01/31/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND The current standard of care for managing peanut allergy includes avoidance of peanut and use of injectable epinephrine; however, strict avoidance is difficult and accidental ingestion is common with potentially serious consequences. Despite vigilance and efforts to minimize the risk of accidental exposure, peanut protein cross-contamination continues to occur in a variety of foods, including baked goods. OBJECTIVE To assess and quantify the presence of peanut protein contamination in certain baked goods. METHODS Randomly selected baked goods were collected from bakeries in the New York and Miami metropolitan areas that sold a variety of ethnic cuisines. A second set of samples from the same bakeries was collected at least 1 week after to evaluate between-batch variability. Samples were sent to the Food Allergy Research and Resource Program to analyze peanut contamination by enzyme-linked immunosorbent assay. Consumption estimates were based on 2003 to 2010 National Health and Nutrition Examination Survey survey data. RESULTS Of 154 samples from 18 bakeries, 4 (2.6%) had detectable peanut contamination with peanut protein levels ranging from 0.1 mg/100 g to 650 mg/100 g. Consumption estimates for single occasion ingestion of a contaminated item ranged from 0.07 mg to 832 mg of peanut protein. CONCLUSION In this study, unintended peanut protein was present in a small, but not insignificant, proportion of baked goods, with the potential to trigger a reaction in individuals with peanut allergy. Some products contained high levels of unintended peanut protein. The current data support the potential for accidental exposure to peanut protein with its associated risk.
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Affiliation(s)
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska; DBV Technologies, Montrouge, France.
| | - J Andrew Bird
- Department of Pediatrics, The University of Texas Southwestern, Dallas, Texas
| | - Vivian Hernandez-Trujillo
- Allergy and Immunology Care Center of South Florida, Division of Allergy & Immunology, Nicklaus Children's Hospital, Miami, Florida
| | | | - Douglas Mack
- McMaster University, Hamilton, Ontario, Canada; Halton Pediatric Allergy, Burlington, Ontario, Canada
| | - Joseph M Chalil
- DBV Technologies, Montrouge, France; Nova Southeastern University, Fort Lauderdale, Florida
| | - Todd D Green
- DBV Technologies, Montrouge, France; UPMC Children's Hospital of Pittsburgh and University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Joseph L Baumert
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska
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Remington BC, Koppelman SJ, Green TD, Lack G, Roberts G, Campbell DE. Predicted number of peanut-allergic patients needed to treat with epicutaneous immunotherapy (EPIT) to prevent one allergic reaction: A novel approach to assessing relevance. Allergy 2021; 76:3223-3226. [PMID: 34077581 PMCID: PMC9291584 DOI: 10.1111/all.14973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 05/04/2021] [Accepted: 05/12/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Benjamin C. Remington
- Food Allergy Research and Resource Program University of Nebraska Lincoln NE USA
- Remington Consulting Group BV Utrecht The Netherlands
| | - Stef J. Koppelman
- Food Allergy Research and Resource Program University of Nebraska Lincoln NE USA
- DBV Technologies Montrouge France
| | - Todd D. Green
- DBV Technologies Montrouge France
- UPMC Children’s Hospital of Pittsburgh Pittsburgh PA USA
| | - Gideon Lack
- Paediatric Allergy Group Department of Women and Children’s Health School of Life Course Sciences King’s College London London UK
- Peter Gorer Department of Immunobiology School of Immunology & Microbial Sciences King’s College London London UK
- Children’s Allergy Service Guy’s and St. Thomas’ NHS Foundation Trust London UK
| | - Graham Roberts
- NIHR Southampton Biomedical Research Centre University Hospital Southampton NHS Foundation Trust Southampton UK
- Clinical and Experimental Sciences and Human Development in Health Faculty of Medicine University of Southampton Southampton UK
- The David Hide Asthma and Allergy Research Centre St Mary’s Hospital Isle of Wight UK
| | - Dianne E. Campbell
- DBV Technologies Montrouge France
- Department of Allergy & Immunology Children’s Hospital at Westmead Sydney NSW Australia
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8
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Apostolovic D, Marsh JT, Baumert J, Taylor SL, Westphal A, de Jongh H, Johnson P, de Jong GAH, Koppelman SJ. Purification and Initial Characterization of Ara h 7, a Peanut Allergen from the 2S Albumin Protein Family. J Agric Food Chem 2021; 69:6318-6329. [PMID: 34037388 DOI: 10.1021/acs.jafc.1c00618] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
2S albumins are important peanut allergens. Within this protein family, Ara h 2 and Ara h 6 have been described in detail, but Ara h 7 has received little attention. We now describe the first purification of Ara h 7 and its characterization. Two Ara h 7 isoforms were purified from peanuts. Mass spectrometry revealed that both the isoforms have a post-translation cleavage, a hydroxyproline modification near the N-terminus, and four disulfide bonds. The secondary structure of both Ara h 7 isoforms is highly comparable to those of Ara h 2 and Ara h 6. Both Ara h 7 isoforms bind IgE, and Ara h 7 is capable of inhibiting the binding between Ara h 2 and IgE, suggesting at least partially cross-reactive IgE epitopes. Ara h 7 was found in all main market types of peanut, at comparable levels. This suggests that Ara h 7 is a relevant allergen from the peanut 2S albumin protein family.
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Affiliation(s)
- Danijela Apostolovic
- Immunology and Allergy Division, Department of Medicine Solna, Karolinska Institutet, Solnavägen 1, 171 77 Solna, Sweden
| | - Justin T Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Joe Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Adrie Westphal
- Biochemistry Dept., Wageningen University and Research, PO Box 17, 6700 AA Wageningen, The Netherlands
| | - Harmen de Jongh
- ProtinConsult, Rozenstraat 19, 3702 VL Zeist, The Netherlands
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
| | - Govardus A H de Jong
- Wageningen University and Research, Food and Biobased Research. PO Box 17, 6700 AA Wageningen, The Netherlands
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, Nebraska 68588-6207, United States
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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: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Remington BC, Campbell DE, Green TD, Fleischer DM, Koppelman SJ. Post hoc analysis of epicutaneous immunotherapy for peanut allergy phase 3 results: Relevance for exposure through restaurant meals. Ann Allergy Asthma Immunol 2020; 126:208-209. [PMID: 33259921 DOI: 10.1016/j.anai.2020.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/12/2020] [Accepted: 11/23/2020] [Indexed: 10/22/2022]
Affiliation(s)
- Benjamin C Remington
- Food Allergy Research and Resource Program, University of Nebraska, Lincoln, Nebraska; Remington Consulting Group B.V., Utrecht, the Netherlands.
| | - Dianne E Campbell
- DBV Technologies SA, Montrouge, France; The Children's Hospital at Westmead, Sydney, Australia
| | - Todd D Green
- DBV Technologies SA, Montrouge, France; UPMC Children's Hospital of Pittsburgh and University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - David M Fleischer
- Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, Colorado
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, University of Nebraska, Lincoln, Nebraska; DBV Technologies SA, Montrouge, France
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Remington BC, Blom WM, Bassa B, Koppelman SJ. Risk of shared equipment in restaurants for consumers with peanut allergy: a simulation for preparing Asian foods: A simulation for preparing Asian foods. Ann Allergy Asthma Immunol 2020; 125:543-551.e6. [PMID: 32763340 DOI: 10.1016/j.anai.2020.07.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/22/2020] [Accepted: 07/27/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Allergic reactions to meals consumed outside the home are common and can be severe and sometimes fatal. OBJECTIVE To quantify the risk reduction potentially achieved by increasing an individual's threshold sensitivity to peanut (such as by means of immunotherapy) in scenarios of peanut exposure through shared kitchen materials in a restaurant setting. METHODS Three versions of popular peanut-containing sauces were selected to represent common ingredients used in Asian cooking. Different combinations of utensils, equipment, sauces, and test conditions were prepared by a professional chef, with or without common cleaning procedures, to represent normal daily practice. Residue amounts of peanut-containing material on kitchen equipment and utensils were measured and used for quantitative risk assessment to model the risk reduction associated with increasing an individual's threshold. RESULTS Shared utensils had mean residue amounts of 23 to 1519 mg peanut protein (no cleaning) and 3 to 82 mg peanut protein (after water rinse). Shared woks and pans had up to 20 mg peanut protein after rinsing. Individuals who reach a threshold of 300 mg peanut protein have a predicted relative risk reduction of 94.9% to greater than 99.99% with brief cleaning. With no cleaning, relative risk reductions were 63.5% to 91.1% for individuals with a baseline threshold of less than or equal to 100 mg peanut protein who reach a threshold of 300 mg peanut protein, increasing to 91% to 99.7% when reaching a threshold value of 1000 mg peanut protein. CONCLUSION In all shared kitchen material scenarios that we studied, achieving an eliciting dose of 300 or 1000 mg peanut protein seems clinically relevant for the peanut-allergic population.
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Affiliation(s)
- Benjamin C Remington
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands; Food Allergy Research and Resource Program, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - W Marty Blom
- Netherlands Organisation for Applied Scientific Research (TNO), Utrecht, The Netherlands
| | | | - Stef J Koppelman
- Food Allergy Research and Resource Program, University of Nebraska-Lincoln, Lincoln, Nebraska.
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12
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Koppelman SJ, Witteveen M, JanssenDuijghuijsen L, Baumert JL, Witkamp RF, Norren K. Detection of peanut allergens in serum: circumventing the inhibitory effect of immunoglobulins. Allergy 2020; 75:1835-1836. [PMID: 32652627 DOI: 10.1111/all.14330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/02/2020] [Accepted: 04/14/2020] [Indexed: 12/01/2022]
Affiliation(s)
- Stef J. Koppelman
- Food Allergy Research and Resource Program Department of Food Science & Technology University of Nebraska Lincoln NE USA
| | - Michel Witteveen
- Nutritional Biology Department of Human Nutrition and Health Wageningen University and Research Wageningen The Netherlands
| | - Lonneke JanssenDuijghuijsen
- Nutritional Biology Department of Human Nutrition and Health Wageningen University and Research Wageningen The Netherlands
- Human and Animal Physiology Wageningen University and Research Wageningen The Netherlands
| | - Joseph L. Baumert
- Food Allergy Research and Resource Program Department of Food Science & Technology University of Nebraska Lincoln NE USA
| | - Renger F. Witkamp
- Nutritional Biology Department of Human Nutrition and Health Wageningen University and Research Wageningen The Netherlands
| | - Klaske Norren
- Nutritional Biology Department of Human Nutrition and Health Wageningen University and Research Wageningen The Netherlands
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13
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de Jongh HHJ, de Jong GAH, Apostolovic D, Taylor SL, Baumert JL, Koppelman SJ. Effect of heat treatment on the conformational stability of intact and cleaved forms ofthe peanut allergen Ara h 6 in relation to its IgE-binding potency. Food Chem 2020; 326:127027. [PMID: 32438232 DOI: 10.1016/j.foodchem.2020.127027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/16/2020] [Accepted: 05/08/2020] [Indexed: 01/14/2023]
Abstract
This work reports on theeffect of heat treatment on the protein conformational stabilityof intact and post-translationallycleaved peanut allergen Ara h 6 in relation to IgE-binding. Intact and post-translationallycleaved Ara h 6 are structurally similar and theirstrong resistance to denaturant-inducedunfolding is comparable. Only upon exposure toautoclave conditions the twoforms of Ara h 6 demonstrated susceptibility toirreversible denaturationresulting in a significant decrease in IgE-binding potency. Thisreduction isfor the intact protein more pronounced than for than for the cleaved form. This isattributed to less conformational constrains of the cleaved form comparedtointact, as suggested by the 2-fold lower activation energy for unfoldingfound for the cleavedform. Overall, harsh conditionsare required to denature Ara h 6 and to significantly reduce its IgE-bindingpotency. The cleavedform possesses more resistance to such denaturation than the intactform.
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Affiliation(s)
| | | | - Danijela Apostolovic
- Clinical Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Solnavägen 1, 171 77 Solna, Sweden
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Joseph L Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
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Abstract
Abstract
Several tests for the detection of soy proteins in foods have been described in the literature, and some are commercially available. This article gives an overview of these methods and discusses the advantages and disadvantages of each individual method. Based on the conclusions of this inventory, an experimental approach was designed to improve the sensitivity of measuring soy protein in processed foods. The aimed sensitivity is 10 ppm (10 μg soy protein in 1 g solid sample), which is over 100-fold lower than presently available tests. The aimed sensitivity is this low because levels of food allergens at 10 ppm and above may provoke reactions in food allergic persons. Native soybean meal, soy protein isolate, soy protein concentrate, and textured soy flakes were used as test materials. Several extraction procedures were compared and a new method using high pH was selected. Polyclonal antibodies were raised in rabbits and goats, and immunopurified antibodies were used in sandwich and inhibition enzyme-linked immunosorbent assay (ELISA). Extraction at pH 12 resulted in good yields for all tested samples, both quantitatively (Bradford) and qualitatively by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunopurified rabbit antibodies against this extract used in a competition ELISA format resulted in a sensitive test with a detection limit of 0.02 μg/mL, corresponding to 0.4 μg/g (0.4 ppm) in food samples. Cross-reactivity with some main food ingredients was measured and appeared to be negative in all cases. The presently developed test is applicable for soy ingredients and soy-containing foods that are processed in different ways. The limit of quantitation is 1 ppm, which is an enormous improvement over earlier described methods.
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Affiliation(s)
- Stef J Koppelman
- TNO Nutrition and Food Research, Zeist, The Netherlands; University Medical Centre Utrecht, Department of Dermatology/Allergology, Utrecht, The Netherlands
| | - Catriona M M Lakemond
- Wageningen University, Centre for Protein Technology TNO–WU, Wageningen, The Netherlands
| | | | - Susan L Hefle
- University of Nebraska, Food Allergy Research and Resource Program, Lincoln, NE
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15
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Remington BC, Krone T, Kim EH, Bird JA, Green TD, Lack G, Fleischer DM, Koppelman SJ. Estimated risk reduction to packaged food reactions by epicutaneous immunotherapy (EPIT) for peanut allergy. Ann Allergy Asthma Immunol 2019; 123:488-493.e2. [PMID: 31442495 DOI: 10.1016/j.anai.2019.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 08/06/2019] [Accepted: 08/11/2019] [Indexed: 01/15/2023]
Abstract
BACKGROUND Peanut allergy is a generally persistent, sometimes life-threatening food allergy. With no treatments demonstrating the ability to cure a food allergy, the focus of drugs in development has been on providing a level of protection against accidental exposure reactions. However, no study has estimated the relative risk reduction of a food-allergic population receiving a specific immunotherapeutic treatment for their allergies. OBJECTIVE To estimate the relative risk reduction when consuming peanut-contaminated packaged food products in a double-blind, placebo-controlled Phase 3 study population of children treated with epicutaneous immunotherapy (EPIT) for 12 months with either a patch containing 250 μg peanut protein (250-μg patch) or a placebo patch. METHODS The probability of an allergic reaction due to the unintended presence of peanut protein in packaged food products was modeled per study group and food category combination using Monte Carlo simulations. Risks per eating occasion of a contaminated packaged food product and the number of individuals per study population predicted to react on a yearly basis were investigated. RESULTS The population treated with the 250-μg patch demonstrated a significantly increased dose-response distribution after 12 months of treatment, which resulted in a relative risk reduction of 73.2% to 78.4% when consuming peanut-contaminated packaged food products. In contrast, no statistically significant change was observed for the placebo group at the 12-month point. CONCLUSION Our study estimates a substantial relative risk reduction for allergic reactions among peanut-allergic children after 12 months of EPIT with the 250-μg patch, supporting the potential real-world clinical relevance of this investigational immunotherapy and its possible role as a future therapy for peanut-allergic children. ClinicalTrials.gov Identifier: NCT02636699.
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Affiliation(s)
- Benjamin C Remington
- Netherlands Organisation for Applied Scientific Research TNO, Zeist, The Netherlands.
| | - Tanja Krone
- Netherlands Organisation for Applied Scientific Research TNO, Zeist, The Netherlands
| | - Edwin H Kim
- University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - J Andrew Bird
- University of Texas Southwestern Medical School, Dallas, Texas
| | - Todd D Green
- DBV Technologies, Montrouge, France; Children's Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
| | - Gideon Lack
- Paediatric Allergy Group, Department of Women and Children's Health, School of Life Course Sciences, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College London, London, United Kingdom; Children's Allergy Service, Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
| | - David M Fleischer
- Children's Hospital Colorado, University of Colorado Denver School of Medicine, Aurora, Colorado
| | - Stef J Koppelman
- DBV Technologies, Montrouge, France; Food Allergy Research and Resource Program, University of Nebraska-Lincoln, Lincoln, Nebraska
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16
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Kleij HPM, Warmenhoven HJM, Ree R, Versteeg SA, Pieters RHH, Dreskin SC, Knulst AC, Hoffen E, Opstelten DJE, Koppelman SJ, Smit JJ. Chemically modified peanut extract shows increased safety while maintaining immunogenicity. Allergy 2019; 74:986-995. [PMID: 30506686 DOI: 10.1111/all.13687] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 10/28/2018] [Accepted: 11/16/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Peanuts are most responsible for food-induced anaphylaxis in adults in developed countries. An effective and safe immunotherapy is urgently needed. The aim of this study was to investigate the immunogenicity, allergenicity, and immunotherapeutic efficacy of a well-characterized chemically modified peanut extract (MPE) adsorbed to Al(OH)3 . METHODS Peanut extract (PE) was modified by reduction and alkylation. Using sera of peanut-allergic patients, competitive IgE-binding assays and mediator release assays were performed. The immunogenicity of MPE was evaluated by measuring activation of human PE-specific T-cell lines and the induction of PE-specific IgG in mice. The safety and efficacy of MPE adsorbed to Al(OH)3 was tested in two mouse models by measuring allergic manifestations upon peanut challenge in peanut-allergic mice. RESULTS Compared to PE, the IgE-binding and capacity to induce allergic symptoms of MPE were lower in all patients. PE and MPE displayed similar immunogenicity in vivo and in vitro. In mice sensitized to PE, the threshold for anaphylaxis (drop in BT) upon subcutaneous challenge with PE was 0.01 mg, while at 0.3 mg MPE no allergic reaction occurred. Anaphylaxis was not observed when PE and MPE were fully adsorbed to Al(OH)3 . Both PE and MPE + Al(OH)3 showed to be efficacious in a model for immunotherapy. CONCLUSION In our studies, an Al(OH)3 adsorbed MPE showed reduced allergenicity compared to unmodified PE, while the efficacy of immunotherapy is maintained. The preclinical data presented in this study supports further development of modified peanut allergens for IT.
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Affiliation(s)
| | | | - Ronald Ree
- Department of Experimental Immunology Academic Medical Center University of Amsterdam Amsterdam The Netherlands
- Department of Otorhinolaryngology Academic Medical Center University of Amsterdam AmsterdamThe Netherlands
| | - Serge A. Versteeg
- Department of Experimental Immunology Academic Medical Center University of Amsterdam Amsterdam The Netherlands
| | - Raymond H. H. Pieters
- Institute for Risk Assessment Sciences Immunotoxicology Utrecht University Utrecht The Netherlands
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology Department of Medicine Denver School of Medicine University of Colorado Aurora Colorado
| | - André C. Knulst
- Department Dermatology/Allergology University Medical Center Utrecht Utrecht University Utrecht The Netherlands
| | - Els Hoffen
- Department Dermatology/Allergology University Medical Center Utrecht Utrecht University Utrecht The Netherlands
| | | | | | - Joost J. Smit
- Institute for Risk Assessment Sciences Immunotoxicology Utrecht University Utrecht The Netherlands
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17
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Remington BC, Koppelman SJ. Shared Cooking Equipment in Restaurants: A Quantitative Risk Assessment for Peanut-Allergic Consumers. J Allergy Clin Immunol 2019. [DOI: 10.1016/j.jaci.2018.12.729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Remington BC, Krone T, Koppelman SJ. Quantitative risk reduction through peanut immunotherapy: Safety benefits of an increased threshold in Europe. Pediatr Allergy Immunol 2018; 29:762-772. [PMID: 30054934 DOI: 10.1111/pai.12961] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/16/2018] [Accepted: 07/19/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND The clinical relevance of increasing an allergic individual's peanut sensitivity threshold by immunotherapy, that is, eliciting dose (ED) to 300 or 1000 mg peanut protein, has not been previously characterized in a European population. In this study, we quantify the clinical benefits of an increased threshold of reaction following immunotherapy for the peanut-allergic individual. METHODS Quantitative risk assessments incorporated numerous inputs to predict the risk of an allergic reaction after exposure to residual peanut protein in packaged foods. The three primary inputs for the risk assessment were the peanut-allergic individual's clinical threshold value, the amount of food consumed per eating occasion of selected packaged foods, and the concentration of peanut protein in the consumed product. Individual risk reductions were calculated for both children and adolescents-adults. RESULTS Using available consumption and packaged food contamination data, children reaching an ED of 300 mg (if initial ED ≤ 100 mg) or 1000 mg (if initial ED 300 mg) achieved >99.99% risk reduction. Adolescents-adults also achieved >99.99% risk reduction in all cases but one. Adolescents-adults who reached an ED of 300 mg (if initial ED ≤ 100 mg) achieved 99.3%-99.9% risk reduction when consuming ice cream. CONCLUSIONS It is concluded that an increase in threshold following immunotherapy which achieves an eliciting dose of 300 or 1000 mg peanut protein is clinically relevant for the European peanut-allergic population. Benefits of an increased threshold include a significant reduction in risk due to traces of peanut protein.
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Affiliation(s)
| | | | - Stef J Koppelman
- Food Allergy Research and Resource Program, University of Nebraska-Lincoln, Lincoln, Nebraska
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19
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de Jong GAH, Jayasena S, Johnson P, Marsh J, Apostolovic D, van Hage M, Nordlee J, Baumert J, Taylor SL, Roucairol C, de Jongh H, Koppelman SJ. Purification and Characterization of Naturally Occurring Post-Translationally Cleaved Ara h 6, an Allergen That Contributes Substantially to the Allergenic Potency of Peanut. J Agric Food Chem 2018; 66:10855-10863. [PMID: 30284821 DOI: 10.1021/acs.jafc.8b03140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The 2S albumin Ara h 6 is one of the most important peanut allergens. A post-translationally cleaved Ara h 6 (pAra h 6) was purified from Virginia type peanuts, and the cleavage site was mapped using high-resolution mass spectrometry. Compared to intact Ara h 6, pAra h 6 lacks a 5-amino acid stretch, resembling amino acids 43-47 (UniProt accession number Q647G9) in the nonstructured loop. Consequently, pAra h 6 consists of two chains: an N-terminal chain of approximately 5 kDa and a C-terminal chain of approximately 9 kDa, held together by disulfide bonds. Intermediate post-translationally cleaved products, in which this stretch is cleaved yet still attached to one of the subunits, are also present. The secondary structure and immunoglobulin E (IgE) binding of pAra h 6 resembles that of intact Ara h 6, indicating that the loss of the nonstructured loop is not critical for maintaining the protein structure. Commercially available monoclonal and polyclonal immunoglobulin G (IgG) antibodies directed to Ara h 6 react with both intact Ara h 6 and pAra h 6, suggesting that the involved epitopes are not located in the area that is post-translationally cleaved. No differences between intact Ara h 6 and pAra h 6 in terms of IgE binding were found, suggesting that the area that is post-translationally cleaved is not involved in IgE epitopes either. For all main cultivars Runner, Virginia, Valencia, and Spanish, intact Ara h 6 and pAra h 6 occur in peanut at similar levels, indicating that pAra h 6 is a consistent and important contributor to the allergenic potency of peanut.
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Affiliation(s)
| | - Shyamali Jayasena
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Justin Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Danijela Apostolovic
- Immunology and Allergy Unit, Department of Medicine Solna , Karolinska Institutet , 171 77 Stockholm , Sweden
| | - Marianne van Hage
- Immunology and Allergy Unit, Department of Medicine Solna , Karolinska Institutet , 171 77 Stockholm , Sweden
| | - Julie Nordlee
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Joe Baumert
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Steve L Taylor
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Camille Roucairol
- DBV Technologies , Development Department , 92120 Montrouge , France
| | | | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
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Koppelman SJ, Smits M, Tomassen M, de Jong GAH, Baumert J, Taylor SL, Witkamp R, Veldman RJ, Pieters R, Wichers H. Release of Major Peanut Allergens from Their Matrix under Various pH and Simulated Saliva Conditions-Ara h2 and Ara h6 Are Readily Bio-Accessible. Nutrients 2018; 10:E1281. [PMID: 30208580 PMCID: PMC6165493 DOI: 10.3390/nu10091281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/28/2018] [Accepted: 08/31/2018] [Indexed: 01/24/2023] Open
Abstract
The oral mucosa is the first immune tissue that encounters allergens upon ingestion of food. We hypothesized that the bio-accessibility of allergens at this stage may be a key determinant for sensitization. Light roasted peanut flour was suspended at various pH in buffers mimicking saliva. Protein concentrations and allergens profiles were determined in the supernatants. Peanut protein solubility was poor in the pH range between 3 and 6, while at a low pH (1.5) and at moderately high pHs (>8), it increased. In the pH range of saliva, between 6.5 and 8.5, the allergens Ara h2 and Ara h6 were readily released, whereas Ara h1 and Ara h3 were poorly released. Increasing the pH from 6.5 to 8.5 slightly increased the release of Ara h1 and Ara h3, but the recovery remained low (approximately 20%) compared to that of Ara h2 and Ara h6 (approximately 100% and 65%, respectively). This remarkable difference in the extraction kinetics suggests that Ara h2 and Ara h6 are the first allergens an individual is exposed to upon ingestion of peanut-containing food. We conclude that the peanut allergens Ara h2 and Ara h6 are quickly bio-accessible in the mouth, potentially explaining their extraordinary allergenicity.
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Affiliation(s)
- Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Mieke Smits
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
| | - Monic Tomassen
- Food & Biobased Research, Wageningen University and Research, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
| | | | - Joe Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Renger Witkamp
- Department of Human Nutrition, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Robert Jan Veldman
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
| | - Raymond Pieters
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
- Institute for Risk Assessment Sciences, Faculty of Veterinary Medicines, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, The Netherlands.
| | - Harry Wichers
- Food & Biobased Research, Wageningen University and Research, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
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21
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Shreffler WG, Baumert JL, Remington BC, Koppelman SJ, Dinakar C, Fleischer DM, Kim E, Tilles SA, Spergel JM. The importance of reducing risk in peanut allergy: Current and future therapies. Ann Allergy Asthma Immunol 2018; 120:124-127. [PMID: 29289463 DOI: 10.1016/j.anai.2017.10.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/20/2017] [Accepted: 10/31/2017] [Indexed: 11/26/2022]
Affiliation(s)
| | - Joe L Baumert
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Nebraska
| | | | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Nebraska
| | | | | | - Edwin Kim
- University of North Carolina, Chapel Hill, North Carolina
| | - Stephen A Tilles
- ASTHMA, Inc. Clinical Research Center; Northwest Asthma and Allergy Center, Seattle, Washington
| | - Jonathan M Spergel
- Division of Allergy and Immunology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
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22
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Spiric J, Koppelman SJ, Knulst A, Nordlee JA, Taylor SL, Baumert JL. In vitro
digestion and characterisation of 2S albumin and digestion-resistant peptides in pecan. Int J Food Sci Technol 2018. [DOI: 10.1111/ijfs.13739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jelena Spiric
- Food Allergy Research and Resource Program; Department of Food Science and Technology; University of Nebraska; Lincoln NE 68588-6207 USA
- Division of Allergology; Paul-Ehrlich-Institut; 63225 Langen Germany
| | - Stef J. Koppelman
- Food Allergy Research and Resource Program; Department of Food Science and Technology; University of Nebraska; Lincoln NE 68588-6207 USA
| | - Andre Knulst
- Department of Dermatology/Allergology; UMC Utrecht; 3584 CX Utrecht The Netherlands
| | - Julie A. Nordlee
- Food Allergy Research and Resource Program; Department of Food Science and Technology; University of Nebraska; Lincoln NE 68588-6207 USA
| | - Steve L. Taylor
- Food Allergy Research and Resource Program; Department of Food Science and Technology; University of Nebraska; Lincoln NE 68588-6207 USA
| | - Joseph L. Baumert
- Food Allergy Research and Resource Program; Department of Food Science and Technology; University of Nebraska; Lincoln NE 68588-6207 USA
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23
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Baumert JL, Taylor SL, Koppelman SJ. Quantitative Assessment of the Safety Benefits Associated with Increasing Clinical Peanut Thresholds Through Immunotherapy. J Allergy Clin Immunol Pract 2017; 6:457-465.e4. [PMID: 28669889 DOI: 10.1016/j.jaip.2017.05.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 04/20/2017] [Accepted: 05/09/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Peanut immunotherapy studies are conducted with the aim to decrease the sensitivity of patients to peanut exposure with the outcome evaluated by testing the threshold for allergic response in a double-blind placebo-controlled food challenge. The clinical relevance of increasing this threshold is not well characterized. OBJECTIVE We aimed to quantify the clinical benefit of an increased threshold for peanut-allergic patients. METHODS Quantitative risk assessment was performed by matching modeled exposure to peanut protein with individual threshold levels. Exposure was modeled by pairing US consumption data for various food product categories with potential contamination levels of peanut that have been demonstrated to be present on occasion in such food products. Cookies, ice cream, doughnuts/snack cakes, and snack chip mixes were considered in the risk assessment. RESULTS Increasing the baseline threshold before immunotherapy from 100 mg or less peanut protein to 300 mg peanut protein postimmunotherapy reduces the risk of experiencing an allergic reaction by more than 95% for all 4 food product categories that may contain trace levels of peanut residue. Further increase in the threshold to 1000 mg of peanut protein had an additional quantitative benefit in risk reduction for all patients reacting to 300 mg or less at baseline. CONCLUSIONS We conclude that achieving thresholds of 300 mg and 1000 mg of peanut protein by peanut immunotherapy is clinically relevant, and that the risk for peanut-allergic patients who have achieved this increased threshold to experience an allergic reaction is reduced in a clinically meaningful way.
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Affiliation(s)
- Joseph L Baumert
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Neb.
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Neb
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science and Technology, University of Nebraska, Lincoln, Neb
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24
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JanssenDuijghuijsen LM, van Norren K, Grefte S, Koppelman SJ, Lenaerts K, Keijer J, Witkamp RF, Wichers HJ. Endurance Exercise Increases Intestinal Uptake of the Peanut Allergen Ara h 6 after Peanut Consumption in Humans. Nutrients 2017; 9:nu9010084. [PMID: 28117717 PMCID: PMC5295128 DOI: 10.3390/nu9010084] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/16/2017] [Accepted: 01/17/2017] [Indexed: 11/16/2022] Open
Abstract
Controlled studies on the effect of exercise on intestinal uptake of protein are scarce and underlying mechanisms largely unclear. We studied the uptake of the major allergen Ara h 6 following peanut consumption in an exercise model and compared this with changes in markers of intestinal permeability and integrity. Ten overnight-fasted healthy non-allergic men (n = 4) and women (n = 6) (23 ± 4 years) ingested 100 g of peanuts together with a lactulose/rhamnose (L/R) solution, followed by rest or by 60 min cycling at 70% of their maximal workload. Significantly higher, though variable, levels of Ara h 6 in serum were found during exercise compared to rest (Peak p = 0.03; area under the curve p = 0.006), with individual fold changes ranging from no increase to an increase of over 150-fold in the uptake of Ara h 6. Similarly, uptake of lactulose (2–18 fold change, p = 0.0009) and L/R ratios (0.4–7.9 fold change, p = 0.04) were significantly increased which indicates an increase in intestinal permeability. Intestinal permeability and uptake of Ara h 6 were strongly correlated (r = 0.77, p < 0.0001 for lactulose and Ara h 6). Endurance exercise after consumption may lead to increased paracellular intestinal uptake of food proteins.
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Affiliation(s)
- Lonneke M JanssenDuijghuijsen
- Wageningen Food and Biobased Research, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
- Nutrition and Pharmacology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
- Human and Animal Physiology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
| | - Klaske van Norren
- Nutrition and Pharmacology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
- Nutricia Research, P.O. Box 80141, 3508 TC Utrecht, The Netherlands.
| | - Sander Grefte
- Human and Animal Physiology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
| | - Stef J Koppelman
- Food Allergy Research and Resource Program, Food Science and Technology, University of Nebraska-Lincoln, Rm 279 Food Innovation Center, P.O. Box 886207, Lincoln, NE 68588-6207, USA.
| | - Kaatje Lenaerts
- Maastricht University Medical Centre, Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
| | - Jaap Keijer
- Human and Animal Physiology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
| | - Renger F Witkamp
- Nutrition and Pharmacology, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
| | - Harry J Wichers
- Wageningen Food and Biobased Research, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
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Koppelman SJ. Reply to letter to the Editor. Food Chem Toxicol 2016; 92:257. [DOI: 10.1016/j.fct.2016.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Baumert JL, Martin L, Thébault C, Taylor SL, Koppelman SJ, Ruban C. Quantitative Assessment of the Safety Benefits Associated with Increasing Clinical Peanut Thresholds through Immunotherapy. J Allergy Clin Immunol 2016. [DOI: 10.1016/j.jaci.2015.12.545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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van Hoffen E, van der Kleij HPM, den Hartog Jager CF, van Doorn WA, Knol EF, Opstelten DJ, Koppelman SJ, Knulst AC. Chemical modification of peanut conglutin reduces IgE reactivity but not T cell reactivity in peanut-allergic patients. Clin Exp Allergy 2015; 44:1558-66. [PMID: 24717146 DOI: 10.1111/cea.12319] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 02/15/2014] [Accepted: 03/24/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Specific immunotherapy for peanut allergy is associated with significant side-effects. Chemically modified allergens may provide a safer alternative. OBJECTIVE This study aimed to analyse the immunogenicity and allergenicity of modified peanut conglutin. METHODS Native peanut conglutin and two modifications thereof were generated (RA and RAGA). Conglutin-specific T cell lines from 11 peanut-allergic patients were analysed for proliferation and cytokine production. Sera from 14 patients were analysed for IgE/IgG1/IgG4 binding by immunoblot and ELISA. IgE reactivity was analysed by direct and indirect basophil activation test (BAT), in presence and absence of patient plasma or CD32-blocking antibodies. RESULTS T cell proliferation to RA was unchanged, and proliferation to RAGA was reduced compared to native conglutin. Cytokine profiles remained unchanged. IgE, IgG1 and IgG4 binding to RA and RAGA was significantly reduced. In the direct BAT, the relative potency of modified conglutin was decreased in 67% and increased/similar in 33% of the patients. In the indirect BAT, RA and RAGA were 10-100 times less potent than native conglutin. Addition of plasma to the indirect BAT increased the relative potency of modified conglutin in patients with high peanut-specific IgG levels. This was mediated via blocking of the response to native conglutin, most likely by soluble IgG, and not via CD32. CONCLUSION AND CLINICAL RELEVANCE Chemical modification of peanut conglutin by RA retains immunogenicity and reduces allergenicity and may be a promising approach for development of a curative treatment for peanut allergy. In a subgroup of patients, where the reactivity of native conglutin is already partially blocked by IgG, the effect of the modification of conglutin is less pronounced.
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Affiliation(s)
- E van Hoffen
- Department of Dermatology/Allergology, University Medical Center Utrecht, Utrecht, The Netherlands
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de Jongh HHJ, de los Reyes Jimenez M, Baumert JL, Taylor SL, Koppelman SJ. Electrophoretic Behavior in Relation to the Structural Integrity of Codfish Parvalbumin upon Heat Treatment. J Agric Food Chem 2015; 63:4683-4689. [PMID: 25880570 DOI: 10.1021/jf505990h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This work evaluates the impact of heat processing of parvalbumin, a major fish allergen, on the consequences for quantitative analysis of this protein embedded in different matrices during heating (either isolated, in an aqueous extract, or in whole fillets) to assess potential health risks. It is shown that oligomerization of parvalbumin does occur, but only upon heat treatment above 80 °C. This coincides with the ability of the isolated protein to refold up to this temperature in a fully reversible way, as demonstrated by circular dichroism analysis. In autoclaved samples a disintegration of the protein structure is observed. The situation becomes different when parvalbumin is embedded in a matrix with other constituents, as in fish extracts or whole fillets. The electrophoretic analysis of parvalbumin (SDS-PAGE and immunoblotting) is largely determined by complexation with other proteins resulting in insoluble materials caused by the partial unfolding of the parvalbumin at elevated temperatures. This effect is more strongly observed for cod fish extract, compared to whole cod fillets, as in the latter situation the integrity of the tissue hampers this interprotein complexation. Moreover, it is shown by ELISA analysis of heat-treated samples that using blotting procedures where disintegration of complexes may be promoted, restoring some of the IgG-binding propensity, may provide false outcomes. It was concluded that antibody binding to parvalbumin is dominated by the potential to form heat-induced complexes with other proteins. The possibly less-soluble or extractable character of these complexes may provide confusing information regarding potential health risks of fish and fish protein-containing food composites when such heat-treated samples are analyzed by immunochemical assays.
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Affiliation(s)
| | | | - Joseph L Baumert
- §Food Allergy Research and Resource Program, Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, United States
| | - Steve L Taylor
- §Food Allergy Research and Resource Program, Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, United States
| | - Stef J Koppelman
- §Food Allergy Research and Resource Program, Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, United States
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Bencharitiwong R, van der Kleij HP, Koppelman SJ, Nowak-Węgrzyn A. Effect of chemical modifications on allergenic potency of peanut proteins. Allergy Asthma Proc 2015; 36:185-91. [PMID: 25976435 DOI: 10.2500/aap.2015.36.3840] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Modification of native peanut extracts could reduce adverse effects of peanut immunotherapy. OBJECTIVE We sought to compare native and chemically modified crude peanut extract (CPE) and major peanut allergens Ara h 2 and Ara h 6 in a mediator-release assay based on the rat basophilic leukemia (RBL) cell line transfected with human Fcε receptor. METHODS Native Ara h 2/6 was reduced and alkylated (RA), with or without additional glutaraldehyde treatment (RAGA). CPE was reduced and alkylated. Sera of subjects with peanut allergy (16 males; median age 7 years) were used for overnight RBL-passive sensitization. Cells were stimulated with 0.1 pg/mL to 10 μg/mL of peanut. β-N-acetylhexosaminidase release (NHR) was used as a marker of RBL degranulation, expressed as a percentage of total degranulation caused by Triton X. RESULTS Median peanut-specific immunoglobulin E was 233 kUA/L. Nineteen subjects were responders, NHR ≥ 10% in the mediator release assay. Responders had reduced NHR by RA and RAGA compared with the native Ara h 2/6. Modification resulted in a later onset of activation by 10- to 100-fold in concentration and a lowering of the maximum release. Modified RA-Ara h 2/6 and RAGA-Ara h 2/6 caused significantly lower maximum mediator release than native Ara h 2/6, at protein concentrations 0.1, 1, and 10 ng/mL (p < 0.001, < 0.001, and < 0.001, respectively, for RA; and < 0.001, 0.026, and 0.041, respectively, for RAGA). RA-CPE caused significantly lower maximum NHR than native CPE, at protein concentration 1 ng/mL (p < 0.001) and 10 ng/mL (p < 0.002). Responders had high rAra h 2 immunoglobulin E (mean, 61.1 kUA/L; p < 0.001) and higher NHR in mediator release assay to native Ara h 2/6 than CPE, which indicates that Ara h 2/6 were the most relevant peanut allergens in these responders. CONCLUSIONS Chemical modification of purified native Ara h 2 and Ara h 6 reduced mediator release in an in vitro assay ∼100-fold, which indicates decreased allergenicity for further development of the alternative candidate for safe peanut immunotherapy.
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Affiliation(s)
- Ramon Bencharitiwong
- Division of Pediatric Allergy and Immunology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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30
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Jayasena S, Smits M, Fiechter D, de Jong A, Nordlee J, Baumert J, Taylor SL, Pieters RH, Koppelman SJ. Comparison of six commercial ELISA kits for their specificity and sensitivity in detecting different major peanut allergens. J Agric Food Chem 2015; 63:1849-1855. [PMID: 25651402 DOI: 10.1021/jf504741t] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Six commercial peanut enzyme-linked immunosorbent assay kits were assessed for their ability to recover peanut from the standard reference material 2387 peanut butter and also for their specificity in detecting four major peanut allergens, Ara h 1, Ara h 2, Ara h 3, and Ara h 6. The percentage recovery of peanut from peanut butter differed across different kits as well as at different sample concentrations. The highest recovery was observed with the Romer and R-Biopharm kits, while four other kits were found to underestimate the protein content of the reference peanut butter samples. Five of the kits were most sensitive in detecting Ara h 3 followed by Ara h 1, while hardly recognizing Ara h 2 and Ara h 6. The other kit showed the highest sensitivity to Ara h 2 and Ara h 6, while Ara h 1 and Ara h 3 were poorly recognized. Although Ara h 2 and Ara h 6 are known to be heat stable and more potent allergens, antisera specific to any of these four peanut proteins/allergens may serve as good markers for the detection of peanut residues.
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Affiliation(s)
- Shyamali Jayasena
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska , 143 Food Industry Complex, Lincoln, Nebraska 68583-0919, United States
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31
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Koid AE, Chapman MD, Hamilton RG, van Ree R, Versteeg SA, Dreskin SC, Koppelman SJ, Wünschmann S. Ara h 6 complements Ara h 2 as an important marker for IgE reactivity to peanut. J Agric Food Chem 2014; 62:206-13. [PMID: 24328145 PMCID: PMC4055559 DOI: 10.1021/jf4022509] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The similarities of two major peanut allergens, Ara h 2 and Ara h 6, in molecular size, amino acid sequence, and structure have made it difficult to obtain natural Ara h 6 free of Ara h 2. The objectives of this study were to purify natural Ara h 6 that is essentially free of Ara h 2 and to compare its IgE reactivity and potency in histamine release assays to Ara h 2. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the highly purified allergen (<0.01% Ara h 2) revealed a single 14.5 kD band, and the identity of Ara h 6 was confirmed by liquid chromatography-tandem mass spectrometry. Ara h 6 showed a higher seroprevalence in chimeric IgE enzyme-linked immunosorbent assay (n = 54) but a weaker biological activity in basophil histamine release assays than Ara h 2. Purified Ara h 6 will be useful for diagnostic IgE antibody assays as well as molecular and cellular studies to investigate the immunological mechanisms of peanut allergy.
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Affiliation(s)
- Audrey E Koid
- INDOOR Biotechnologies, Inc., 1216 Harris St, Charlottesville, VA 22903
| | - Martin D Chapman
- INDOOR Biotechnologies, Inc., 1216 Harris St, Charlottesville, VA 22903
| | - Robert G Hamilton
- Johns Hopkins University School of Medicine, 600 N Wolfe St #6-113, Baltimore, MD 21287
| | - Ronald van Ree
- Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam-Zuidoost, The Netherlands
| | - Serge A Versteeg
- Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam-Zuidoost, The Netherlands
| | - Stephen C Dreskin
- University of Colorado Denver, School of Medicine, 1250 14th St, Denver, CO 80202
| | | | - Sabina Wünschmann
- INDOOR Biotechnologies, Inc., 1216 Harris St, Charlottesville, VA 22903
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32
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Van Bilsen JH, Knippels LM, Penninks AH, Nieuwenhuizen WF, De Jongh HH, Koppelman SJ. The protein structure determines the sensitizing capacity of Brazil nut 2S albumin (Ber e1) in a rat food allergy model. Clin Transl Allergy 2013; 3:36. [PMID: 24180644 PMCID: PMC3827886 DOI: 10.1186/2045-7022-3-36] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/18/2013] [Indexed: 12/28/2022] Open
Abstract
It is not exactly known why certain food proteins are more likely to sensitize. One of the characteristics of most food allergens is that they are stable to the acidic and proteolytic conditions in the digestive tract. This property is thought to be a risk factor in allergic sensitization. The purpose of the present study was to investigate the contribution of the protein structure of 2S albumin (Ber e1), a major allergen from Brazil nut, on the sensitizing capacity in vivo using an oral Brown Norway rat food allergy model. Disulphide bridges of 2S albumin were reduced and alkylated resulting in loss of protein structure and an increased pepsin digestibility in vitro. Both native 2S albumin and reduced/alkylated 2S albumin were administered by daily gavage dosing (0.1 and 1 mg) to Brown Norway rats for 42 days. Intraperitoneal administration was used as a positive control. Sera were analysed by ELISA and passive cutaneous anaphylaxis. Oral exposure to native or reduced/alkylated 2S albumin resulted in specific IgG1 and IgG2a responses whereas only native 2S albumin induced specific IgE in this model, which was confirmed by passive cutaneous anaphylaxis. This study has shown that the disruption of the protein structure of Brazil nut 2S albumin decreased the sensitizing potential in a Brown Norway rat food allergy model, whereas the immunogenicity of 2S albumin remained preserved. This observation may open possibilities for developing immunotherapy for Brazil nut allergy.
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Affiliation(s)
| | - Léon Mj Knippels
- TNO, Zeist, Netherlands.,Nutricia Research, Utrecht, Netherlands
| | | | | | | | - Stef J Koppelman
- TNO, Zeist, Netherlands.,Food Allergy Research and Resource Program, University of Nebraska, Lincoln, Nebraska, USA
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33
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Apostolovic D, Luykx D, Warmenhoven H, Verbart D, Stanic-Vucinic D, de Jong GAH, Velickovic TC, Koppelman SJ. Reduction and alkylation of peanut allergen isoforms Ara h 2 and Ara h 6; characterization of intermediate- and end products. Biochim Biophys Acta 2013; 1834:2832-42. [PMID: 24145103 DOI: 10.1016/j.bbapap.2013.10.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 09/12/2013] [Accepted: 10/04/2013] [Indexed: 10/26/2022]
Abstract
Conglutins, the major peanut allergens, Ara h 2 and Ara h 6, are highly structured proteins stabilized by multiple disulfide bridges and are stable towards heat-denaturation and digestion. We sought a way to reduce their potent allergenicity in view of the development of immunotherapy for peanut allergy. Isoforms of conglutin were purified, reduced with dithiothreitol and subsequently alkylated with iodoacetamide. The effect of this modification was assessed on protein folding and IgE-binding. We found that all disulfide bridges were reduced and alkylated. As a result, the secondary structure lost α-helix and gained some β-structure content, and the tertiary structure stability was reduced. On a functional level, the modification led to a strongly decreased IgE-binding. Using conditions for limited reduction and alkylation, partially reduced and alkylated proteins were found with rearranged disulfide bridges and, in some cases, intermolecular cross-links were found. Peptide mass finger printing was applied to control progress of the modification reaction and to map novel disulfide bonds. There was no preference for the order in which disulfides were reduced, and disulfide rearrangement occurred in a non-specific way. Only minor differences in kinetics of reduction and alkylation were found between the different conglutin isoforms. We conclude that the peanut conglutins Ara h 2 and Ara h 6 can be chemically modified by reduction and alkylation, such that they substantially unfold and that their allergenic potency decreases.
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Affiliation(s)
- Danijela Apostolovic
- HAL Allergy B.V., J.H. Oortweg 15-17, 2333 CH Leiden, The Netherlands; Faculty of Chemistry, University of Belgrade, Studentski trg 16, 11 000 Belgrade, Serbia
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Lee PW, Nordlee JA, Koppelman SJ, Baumert JL, Taylor SL. Measuring parvalbumin levels in fish muscle tissue: relevance of muscle locations and storage conditions. Food Chem 2012; 135:502-7. [PMID: 22868120 DOI: 10.1016/j.foodchem.2012.05.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 04/17/2012] [Accepted: 05/02/2012] [Indexed: 11/28/2022]
Abstract
Fish is an allergenic food capable of provoking severe anaphylactic reactions. Parvalbumin is the major allergen identified in fish and frog muscles. Antibodies against fish and frog parvalbumin have been used to quantify parvalbumin levels from fish. However, these antibodies react variably with parvalbumin from different fish species. Several factors might be responsible for this variation including instability of parvalbumin in fish muscle as a result of frozen storage and differential parvalbumin expression in muscles from various locations within the whole fish. We aimed to investigate whether these factors contribute to the previously observed variable immunoreactivity of the anti-parvalbumin antibodies. Results showed the detection of parvalbumin by these antibodies was unaffected by frozen storage of muscles for 112 days. However, the parvalbumin content decreased in fish muscles from anterior to posterior positions. This factor may partially explain for the inconsistent reactivity of anti-parvalbumin antibodies to different fish species.
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Affiliation(s)
- Poi-Wah Lee
- Food Allergy Research and Resource Program, University of Nebraska, Lincoln, NE, USA
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35
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Lee PW, Nordlee JA, Koppelman SJ, Baumert JL, Taylor SL. Evaluation and comparison of the species-specificity of 3 antiparvalbumin IgG antibodies. J Agric Food Chem 2011; 59:12309-12316. [PMID: 21999209 DOI: 10.1021/jf203277z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Parvalbumin is a pan-allergen in fish and frogs that triggers IgE-mediated reactions in fish-allergic individuals. Previous studies demonstrated that antibodies raised against fish and frog parvalbumins displayed varying specificity for different fish species, and thus, the applicability of these antibodies for potential use in immunoassays to detect fish residues were limited. We aimed to determine the specificity of 3 IgG antibodies for various fish species. Indirect enzyme-linked immunosorbent assay (ELISA) and IgG-immunoblotting were used to compare the reactivity of the polyclonal anticod parvalbumin antibody and the commercially available, monoclonal antifrog and monoclonal anticarp parvalbumin antibodies against raw muscle extracts of 29 fish species. All antibodies demonstrated varying specificities for different fish species. Of the 3 antibodies, the polyclonal anticod parvalbumin antibody is the most suitable for the detection of fish parvalbumins as it showed reactivity to the widest range of species, including herring, pilchard, carp, pike, cod, pollock, haddock, cusk, hake, bluegill, tilapia, bass, grouper, trout, catfish, and perch, although detection was still limited for several key fish species.
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Affiliation(s)
- Poi-Wah Lee
- Food Allergy Research and Resource Program, University of Nebraska, Lincoln, Nebraska, United States
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36
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Koppelman SJ, Hefle SL, Taylor SL, de Jong GAH. Digestion of peanut allergens Ara h 1, Ara h 2, Ara h 3, and Ara h 6: a comparative in vitro study and partial characterization of digestion-resistant peptides. Mol Nutr Food Res 2011; 54:1711-21. [PMID: 20603832 DOI: 10.1002/mnfr.201000011] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
SCOPE There are differences in stability to pepsin between the major allergens in peanut; however, data are from different reports using different digestion models. This study provides a comprehensive comparison of the digestibility of the major peanut allergens. METHODS AND RESULTS Peanut allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 were incubated with pepsin to mimic the effect of gastric digestion. Samples were analyzed using SDS-PAGE. To further investigate resistance to digestion, Ara h 2 was additionally subjected to digestion with trypsin and residual peptides were characterized. Ara h 1 and Ara h 3 were rapidly hydrolyzed by pepsin. On the contrary, Ara h 2 and Ara h 6 were resistant to pepsin digestion, even at very high concentrations of pepsin. In fact, limited proteolysis could only be demonstrated by SDS-PAGE performed under reducing conditions, indicating an important role for the disulfide bridges in maintaining the quaternary structure of Ara h 2 and Ara h 6. Trypsin digestion of Ara h 2 similarly resulted in large residual peptides and these were identified. CONCLUSION Ara h 2 and Ara h 6 are considerably more stable towards digestion than Ara h 1 and Ara h 3.
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37
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Jacobs JFM, Baumert JL, Brons PP, Joosten I, Koppelman SJ, van Pampus ECM. Anaphylaxis from passive transfer of peanut allergen in a blood product. N Engl J Med 2011; 364:1981-2. [PMID: 21591965 DOI: 10.1056/nejmc1101692] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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de Jongh HH, Taylor SL, Koppelman SJ. Controlling the aggregation propensity and thereby digestibility of allergens by Maillardation as illustrated for cod fish parvalbumin. J Biosci Bioeng 2011; 111:204-11. [DOI: 10.1016/j.jbiosc.2010.09.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 09/23/2010] [Accepted: 09/27/2010] [Indexed: 10/18/2022]
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Koppelman SJ, Romijn RA, de Jongh HH, Nordlee JA, Piersma S, Hessing M, Taylor SL. Purification of Parvalbumin from Carp: A Protocol that Avoids Heat-Treatment. J Food Sci 2010; 75:T49-56. [DOI: 10.1111/j.1750-3841.2010.01513.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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40
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Peeters KABM, Koppelman SJ, Penninks AH, Lebens A, Bruijnzeel-Koomen CAFM, Hefle SL, Taylor SL, van Hoffen E, Knulst AC. Clinical relevance of sensitization to lupine in peanut-sensitized adults. Allergy 2009; 64:549-55. [PMID: 19076544 DOI: 10.1111/j.1398-9995.2008.01818.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND The use of lupine in food has been increasing during the last decade and allergic reactions to lupine have been reported, especially in peanut-allergic patients. The frequency and the degree of cross-reactivity to other legumes are not known. The aim of the study was to investigate the frequency of sensitization to lupine, and in addition to pea and soy, and its clinical relevance, in peanut-sensitized patients. Furthermore, to determine the eliciting dose (ED) for lupine using double-blind placebo-controlled food challenges (DBPCFC). METHODS Thirty-nine unselected peanut-sensitized patients were evaluated by skin prick tests (SPT) and ImmunoCAP to lupine, pea, and soy. Clinical reactivity was measured by DBPCFC for lupine, and by history for pea and soy. RESULTS Eighty-two percent of the study population was sensitized to lupine, 55% to pea, and 87% to soy. Clinically relevant sensitization to lupine, pea, or soy occurred in 35%, 29%, and 33% respectively of the study population. None of the patients was aware of the use of lupine in food. The lowest ED for lupine, inducing mild subjective symptoms, was 0.5 mg, and the no observed adverse effect level (NOAEL) was 0.1 mg. No predictive factors for lupine allergy were found. CONCLUSION In peanut-sensitized patients, clinically relevant sensitization to either lupine or to pea or soy occurs frequently. The ED for lupine is low (0.5 mg), which is only fivefold higher than for peanut. Patients are not aware of lupine allergy and the presence of lupine in food, indicating that education is important to build awareness.
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Affiliation(s)
- K A B M Peeters
- Department of Dermatology/Allergology, University Medical Center Utrecht, The Netherlands
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41
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Koppelman SJ, Luykx DMAM, de Jongh HHJ, Veldhuizen WJ. Physicochemical characterization of allergens: quantity, identity, purity, aggregation and conformation. Arb Paul Ehrlich Inst Bundesinstitut Impfstoffe Biomed Arzneim Langen Hess 2009; 96:39-54. [PMID: 20799444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Allergens and allergoids can be characterized by means of physicochemical methods, resulting in a description of the protein on different structural levels. Several techniques are available and their suitability depends on the composition of the particular sample. Current European legislation on allergen products demands characterization of final products in particular focusing on identity, degree of modification (for allergoids) and stability of the composition. Structural parameters of allergens may be used to investigate the stability of an allergen product. The challenge is to identify and optimize techniques that allow determination of protein structure in the context of a formulated pharmaceutical product. As the majority of the products currently marketed are formulated with aluminium hydroxide or aluminium phosphate as a depot, most of the methods and techniques used for protein characterization in solution are not applicable. An additional hurdle is that allergen products are based on natural extracts, comprising a mixture of proteins, both allergens and non-allergens, sometimes in the presence of other uncharacterized components from the raw material. This paper describes which methods are suitable for the different stages of allergen product manufacturing, and how these relate to the current regulatory requirements. Some of the techniques are demonstrated using a model allergen, cod parvalbumin, and a chemically modified form thereof. We conclude that a variety of methods is available for characterization of proteins in solution, and that a limited number of techniques appear to be suitable for modified allergens (allergoids). Adaptation of existing methods, e.g. mass spectroscopy and infrared spectroscopy may be helpful to obtain protein parameters of allergens in a formulated allergen product. By choosing a combination of techniques, including those additional to physicochemical approaches, relevant parameters of allergens in formulated allergen products can be assessed in order to achieve a well-characterized pharmaceutical product.
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van Boxtel EL, Koppelman SJ, van den Broek LA, Gruppen H. Heat denaturation of Brazil nut allergen Ber e 1 in relation to food processing. Food Chem 2008; 110:904-8. [DOI: 10.1016/j.foodchem.2008.02.078] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 01/02/2008] [Accepted: 02/27/2008] [Indexed: 11/24/2022]
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van Boxtel EL, van den Broek LAM, Koppelman SJ, Gruppen H. Legumin allergens from peanuts and soybeans: effects of denaturation and aggregation on allergenicity. Mol Nutr Food Res 2008; 52:674-82. [PMID: 18338408 DOI: 10.1002/mnfr.200700299] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Legumin proteins Ara h 3 from peanuts and glycinin from soybeans are increasingly described as important allergens. The stability of an allergen's IgE binding capacity towards heating and digestion is considered an important characteristic for food allergens. We investigated the effects of heating and digestion on the IgE binding of Ara h 3 and glycinin. Both proteins are relatively stable to denaturation, having denaturation temperatures ranging from 70 to 92 degrees C, depending on their quaternary structure and the ionic strength. Aggregates were formed upon heating, which were partly soluble for glycinin. Heating slightly decreased the pepsin digestion rate of both allergens. However, heating did not affect the IgE binding capacity of the hydrolyzates, as after only 10 min of hydrolysis no IgE binding could be detected any more in all samples. Peanut allergen Ara h 1, when digested under equal conditions, still showed IgE binding after 2 h of hydrolysis. Our results indicate that the IgE binding capacity of legumin allergens from peanuts and soybeans does not withstand peptic digestion. Consequently, these allergens are likely unable to sensitize via the gastro-intestinal tract and cause systemic food allergy symptoms. These proteins might thus be less important allergens than was previously assumed.
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Affiliation(s)
- Evelien L van Boxtel
- Laboratory of Food Chemistry, Wageningen University, EV Wageningen, The Netherlands
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van Boxtel EL, Koppelman SJ, van den Broek LAM, Gruppen H. Determination of pepsin-susceptible and pepsin-resistant epitopes in native and heat-treated peanut allergen Ara h 1. J Agric Food Chem 2008; 56:2223-2230. [PMID: 18298062 DOI: 10.1021/jf072907n] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This study was aimed at the determination of the pepsin-susceptible and pepsin-resistant epitopes in native and heat-treated Ara h 1, a major allergen from peanuts. Both the oligomeric structure and the trimeric structure of the allergen were investigated. Under the in vitro conditions applied, oligomeric Ara h 1, either unheated or preheated, was hydrolyzed by pepsin at a lower rate than trimeric Ara h 1. Peptides with relatively high molecular masses were shown to be able to bind IgE, whereas peptides with lower molecular masses (<2 kDa) did not. In these latter fractions, fragments of 15 previously published epitopes of mature Ara h 1 were identified. As a result, these epitopes are not likely responsible for the induction of systemic food allergic reactions to peanuts. Using sequential chymotrypsin digestion, the pepsin-resistant IgE-binding peptides were deduced to contain the previously identified intact epitopes EDWRRPSHQQ (amino acids 50-59) and PRKIRPEG (amino acids 60-67). The presence of four additional earlier published intact epitopes (covering amino acids 6-13, 14-21, 24-31, and 40-47) on the pepsin-resistant peptides could be neither deduced nor ruled out. The two deduced and four possible pepsin-resistant epitopes are all situated in the N-terminal part of Ara h 1, which does not show homology with other vicilin proteins. Consequently, this unique N-terminal part of Ara h 1 is proposed to be responsible for the allergen's ability to induce systemic allergic reactions.
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Affiliation(s)
- Evelien L van Boxtel
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
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van Boxtel EL, van den Broek LAM, Koppelman SJ, Vincken JP, Gruppen H. Peanut allergen Ara h 1 interacts with proanthocyanidins into higher molecular weight complexes. J Agric Food Chem 2007; 55:8772-8. [PMID: 17883255 DOI: 10.1021/jf071585k] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Mildly extracted peanut allergen Ara h 1 was previously reported to occur as an oligomeric complex. In this paper we describe how the protein in this oligomeric complex interacts noncovalently with phenolic compounds of the proanthocyanidin type. These interactions are being disrupted during anion exchange chromatography, resulting in the dissociation of the oligomeric Ara h 1 complex into protein trimers. By use of the known three-dimensional structure of beta-conglycinin, a soy protein homologous to Ara h 1, proline-rich regions were observed in silico on both faces of its trimeric structure, which are conserved in Ara h 1. These proline-rich regions could explain the binding of proanthocyanidins to Ara h 1 and the formation of multiple Ara h 1 trimer complexes. This was supported by the observation that the addition of peanut proanthocyanidins to trimeric Ara h 1 and to beta-conglycinin resulted in the formation of soluble oligomeric protein complexes. The structurally related legumin proteins do not contain such proline-rich regions on both sides of the protein, and proanthocyanidins were shown to have a lower affinity for legumin proteins from peanuts and soybeans (peanut allergen Ara h 3 and soy glycinin, respectively). Ara h 1 present as the oligomeric complex is assumed to be the representative form of the allergen in which it is consumed by humans.
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Affiliation(s)
- Evelien L van Boxtel
- Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
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Peeters KABM, Koppelman SJ, van Hoffen E, van der Tas CWH, den Hartog Jager CF, Penninks AH, Hefle SL, Bruijnzeel-Koomen CAFM, Knol EF, Knulst AC. Does skin prick test reactivity to purified allergens correlate with clinical severity of peanut allergy? Clin Exp Allergy 2007; 37:108-15. [PMID: 17210048 DOI: 10.1111/j.1365-2222.2006.02628.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Recognition of specific peanut allergens or the diversity of IgE binding to peanut allergens may play a role in the elicitation of severe allergic reactions. OBJECTIVE To investigate whether sensitization to individual allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 is correlated with clinical severity. METHODS The reactivity of purified peanut allergens was measured by skin prick test (SPT) and by IgE immunoblot in 30 patients. The results were related to the clinical reactivity by history, and in 25 of them to the eliciting dose (ED). RESULTS The majority of patients recognized Ara h 2 and Ara h 6. Patients with severe symptoms had a higher SPT response to Ara h 2 and Ara h 6 at low concentrations (0.1 micro g/mL) and to Ara h 1 and Ara h 3 at higher concentrations (100 micro g/mL), compared with patients with mild symptoms. They also recognized a greater number of allergens and showed a higher cumulative SPT response compared with patients with mild symptoms. No significant differences were observed between patients with a low or high ED. CONCLUSIONS Ara h 2 and Ara h 6 appeared to be more potent than Ara h 1 and Ara h 3. Both SPT reactivity to low concentrations of Ara h 2 and Ara h 6 and to higher concentrations of Ara h 1 and Ara h 3 were shown to be indicative of severe symptoms.
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Affiliation(s)
- K A B M Peeters
- Department of Dermatology/Allergology, University Medical Centre Utrecht, Utrecht, The Netherlands.
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Koppelman SJ, Vlooswijk R, Bottger G, Van Duijn G, Van der Schaft P, Dekker J, Van Bergen H. Development of an enzyme-linked immunosorbent assay method to detect mustard protein in mustard seed oil. J Food Prot 2007; 70:179-83. [PMID: 17265878 DOI: 10.4315/0362-028x-70.1.179] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An enzyme-linked immunosorbent assay for the detection of mustard protein was developed. The assay is based on a polyclonal antiserum directed against a mixture of mustard proteins raised in rabbits. The assay has a detection limit of 1.5 ppm (milligrams per kilogram) and is suitable for the detection of traces of mustard protein in mustard seed-derived flavoring ingredients. Limited cross-reactivity testing showed that no other plant proteins reacted significantly. From the animal proteins tested, only milk showed some cross-reactivity. With this sensitive assay, it was shown that refined mustard seed oil produced by steam distillation does not contain detectable amounts of mustard protein. Mustard seed oil is used as a flavoring in very low quantities, typically between 40 and 200 mg/kg. Thus, 100 g of a food product flavored with 200 mg of mustard seed oil per kg containing < 1.5 mg of protein per kg would represent an amount of mustard seed protein of <30 ng. Taking into account the published literature on allergic reactions to the unintended ingestion of mustard, this conservatively low calculated level indicates that it is unlikely that food products containing mustard seed oil as a flavoring ingredient will elicit an allergic reaction in mustard-allergic individuals.
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Affiliation(s)
- Stef J Koppelman
- TNO Nutrition and Food Research, Zeist, The Netherlands/Kerklaan 53, NL-3731 EG De Bilt, The Netherlands.
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van Boxtel EL, van Beers MMC, Koppelman SJ, van den Broek LAM, Gruppen H. Allergen Ara h 1 occurs in peanuts as a large oligomer rather than as a trimer. J Agric Food Chem 2006; 54:7180-6. [PMID: 16968080 DOI: 10.1021/jf061433+] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Ara h 1, a major peanut allergen, is known as a stable trimeric protein. Nevertheless, upon purification of native Ara h 1 from peanuts using only size exclusion chromatography, the allergen appeared to exist in an oligomeric structure, rather than as a trimeric structure. The oligomeric structure was independent of the salt concentration applied. Subjecting the allergen to anion exchange chromatography induced the allergen to dissociate into trimers. Ammonium sulfate precipitation did not bring about any structural changes, whereas exposing the allergen to hydrophobic interaction chromatography caused it to partly dissociate into trimers, with increasing amounts of trimers at higher ionic strengths. The (partial) dissociation into trimers led to a change in the tertiary structure of the monomeric subunits of the allergen, with the monomers in Ara h 1 oligomers having a more compact tertiary structure compared with the monomers in Ara h 1 trimers. As structural characteristics are important for a protein's allergenicity, this finding may imply a different allergenicity for Ara h 1 than previously described.
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Affiliation(s)
- Evelien L van Boxtel
- Laboratory of Food Chemistry, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands
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van Boxtel EL, van Koningsveld GA, Koppelman SJ, van den Broek LAM, Voragen AGJ, Gruppen H. Expanded bed adsorption as a fast technique for the large-scale purification of the complete isoform pool of Ber e 1, the major allergen from Brazil nuts. Mol Nutr Food Res 2006; 50:275-81. [PMID: 16521161 DOI: 10.1002/mnfr.200500203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A new, fast, large-scale purification method for Ber e 1, the major allergen from Brazil nuts, using expanded bed adsorption (EBA) chromatography, is presented. Using EBA, crude extracts can be applied to a fluidized column, which allows the unhindered passage of particulate impurities, thereby avoiding time-consuming centrifugation or filtration steps. With this new purification method, 2.8 g of Ber e 1 was obtained from 85 g defatted Brazil nut meal, essentially within 1 day. Various structural as well as immunochemical characteristics of the purified protein were determined, and compared to those of Ber e 1 purified using conventional chromatographic techniques. The complete pool of Ber e 1 isoforms was collected using EBA. The most abundant isoforms were observed to have pI around 8 and heterogeneity was observed in both the large and the small subunit of the heterodimeric protein. Ber e 1 has a highly ordered secondary structure. No apparent differences in immune reactivity were observed between EBA purified Ber e 1 and conventionally purified Ber e 1, using IgE-binding experiments. Thus, using EBA, Ber e 1 can be purified fast and on gram-scale, while having purity equal to that of conventionally purified Ber e 1.
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Abstract
The allergen Ara h 3 has been purified recently from peanuts. In contrast to recombinant Ara h 3, a 60 kDa single-chain polypeptide, the allergen isolated from its native source is extensively proteolytically processed. The characteristic proteolytic processing for 11S plant storage proteins of the glycinin family is observed for Ara h 3 yielding an acidic and a basic subunit, bound by a disulfide bridge. In addition to this, proteolytic truncation is observed for the acidic subunit but not for the basic subunit of Ara h 3. A series of Ara h 3 polypeptides ranging from 13-45 kDa was separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and each band was digested by trypsin. Peptides related to the bands were identified and a scheme positioning the different polypeptides in the Ara h 3 sequence has been constructed. Peptide analysis showed sequence heterogeneity at two positions indicating the presence of multiple genes encoding variant, but highly homologous Ara h 3 proteins. The pool of Ara h 3 polypeptides from its native source illustrated that allergen from the peanut is much more complex than the recombinant protein used for epitope mapping experiments. From several Ara h 3 truncation products one or more immunoglobulin E (IgE) binding sites had been removed. Characterization of the allergenicity of Ara h 3 should therefore also include IgE-binding studies with peanut-derived Ara h 3, providing the high degree of variation in the Ara h 3 protein structure, as this is what peanut-allergic individuals are confronted with.
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Affiliation(s)
- Sander R Piersma
- FOM Institute for Atomic and Molecular Physics, Amsterdam, The Netherlands.
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