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Fernández-Lozano C, Rita CG, Barra-Castro A, de la Hoz Caballer B, Roldán E, Pueyo López C, Martinez-Botas J, Berges-Gimeno MP. Specific IgE and Basophil Activation Test by Microarray: A Promising Tool for Diagnosis of Platinum Compound Hypersensitivity Reactions. Int J Mol Sci 2024; 25:3890. [PMID: 38612700 PMCID: PMC11011729 DOI: 10.3390/ijms25073890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Drug hypersensitivity reactions (DHRs) to platinum-based compounds (PCs) are on the rise, and their personalized and safe management is essential to enable first-line treatment for these cancer patients. This study aimed to evaluate the usefulness of the basophil activation test by flow cytometry (BAT-FC) and the newly developed sIgE-microarray and BAT-microarray in diagnosing IgE-mediated hypersensitivity reactions to PCs. A total of 24 patients with DHRs to PCs (20 oxaliplatin and four carboplatin) were evaluated: thirteen patients were diagnosed as allergic with positive skin tests (STs) or drug provocation tests (DPTs), six patients were diagnosed as non-allergic with negative STs and DPTs, and five patients were classified as suspected allergic because DPTs could not be performed. In addition, four carboplatin-tolerant patients were included as controls. The BAT-FC was positive in 2 of 13 allergic patients, with a sensitivity of 15.4% and specificity of 100%. However, the sIgE- and BAT-microarray were positive in 11 of 13 DHR patients, giving a sensitivity of over 84.6% and a specificity of 90%. Except for one patient, all samples from the non-allergic and control groups were negative for sIgE- and BAT-microarray. Our experience indicated that the sIgE- and BAT-microarray could be helpful in the endophenotyping of IgE-mediated hypersensitivity reactions to PCs and may provide an advance in decision making for drug provocation testing.
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Affiliation(s)
- Carlos Fernández-Lozano
- Biochemistry-Research Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain;
- Allergology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain; (A.B.-C.); (B.d.l.H.C.)
| | - Claudia Geraldine Rita
- Immunology Service, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain; (C.G.R.); (E.R.)
- Department of Medicine and Health Sciences, Alcalá University, 28801 Madrid, Spain
| | - Alicia Barra-Castro
- Allergology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain; (A.B.-C.); (B.d.l.H.C.)
| | - Belén de la Hoz Caballer
- Allergology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain; (A.B.-C.); (B.d.l.H.C.)
- Department of Medicine and Health Sciences, Alcalá University, 28801 Madrid, Spain
| | - Ernesto Roldán
- Immunology Service, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain; (C.G.R.); (E.R.)
| | - Cristina Pueyo López
- Pharmacy Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain;
| | - Javier Martinez-Botas
- Biochemistry-Research Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain;
| | - María Pilar Berges-Gimeno
- Allergology Department, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, Carretera de Colmenar Km 9, 28034 Madrid, Spain; (A.B.-C.); (B.d.l.H.C.)
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Trifonova D, Curin M, Riabova K, Karsonova A, Keller W, Grönlund H, Käck U, Konradsen JR, van Hage M, Karaulov A, Valenta R. Allergenic Activity of Individual Cat Allergen Molecules. Int J Mol Sci 2023; 24:16729. [PMID: 38069052 PMCID: PMC10706119 DOI: 10.3390/ijms242316729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 12/18/2023] Open
Abstract
More than 10% of the world's population suffers from an immunoglobulin E (IgE)-mediated allergy to cats which is accompanied mainly by respiratory symptoms such as rhinitis and asthma. Several cat allergen molecules have been identified, but their allergenic activity has not been investigated in depth. Purified cat allergen molecules (Fel d 1, Fel d 2, Fel d 3, Fel d 4, Fel d 6, Fel d 7 and Fel d 8) were characterized via mass spectrometry and circular dichroism spectroscopy regarding their molecular mass and fold, respectively. Cat-allergen-specific IgE levels were quantified via ImmunoCAP measurements in IgE-sensitized subjects with (n = 37) and without (n = 20) respiratory symptoms related to cat exposure. The allergenic activity of the cat allergens was investigated by loading patients' IgE onto rat basophils expressing the human FcεRI receptor and studying the ability of different allergen concentrations to induce β-hexosaminidase release. Purified and folded cat allergens with correct masses were obtained. Cat-allergen-specific IgE levels were much higher in patients with a respiratory allergy than in patients without a respiratory allergy. Fel d 1, Fel d 2, Fel d 4 and Fel d 7 bound the highest levels of specific IgE and already-induced basophil degranulation at hundred-fold-lower concentrations than the other allergens. Fel d 1, Fel d 4 and Fel d 7 were recognized by more than 65% of patients with a respiratory allergy, whereas Fel d 2 was recognized by only 30%. Therefore, in addition to the major cat allergen Fel d 1, Fel d 4 and Fel d 7 should also be considered to be important allergens for the diagnosis and specific immunotherapy of cat allergy.
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Affiliation(s)
- Daria Trifonova
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria; (D.T.)
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, 119991 Moscow, Russia (A.K.)
| | - Mirela Curin
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria; (D.T.)
| | - Ksenja Riabova
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, 119991 Moscow, Russia (A.K.)
| | - Antonina Karsonova
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, 119991 Moscow, Russia (A.K.)
| | - Walter Keller
- Institute of Molecular Biosciences, BioTechMed Graz, University of Graz, 8010 Graz, Austria;
| | - Hans Grönlund
- Therapeutic Immune Design Unit, Department of Clinical Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden;
| | - Ulrika Käck
- Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, 11883 Stockholm, Sweden;
| | - Jon R. Konradsen
- Pediatric Allergy and Pulmonology, Astrid Lindgren Children’s Hospital, Karolinska University Hospital, 17164 Stockholm, Sweden
- Department of Women’s and Children’s Health, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Marianne van Hage
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet and University Hospital, 17177 Stockholm, Sweden;
| | - Alexander Karaulov
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, 119991 Moscow, Russia (A.K.)
| | - Rudolf Valenta
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria; (D.T.)
- Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, 119991 Moscow, Russia (A.K.)
- Karl Landsteiner University for Healthcare Sciences, 3500 Krems, Austria
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Jeong JY, Kim SO, Bang S, Choi Y, Shin J, Choi D, Lee SE, Park TH, Hong S. Adaptive biosensing platform using immune cell-based nanovesicles for food allergen detection. Biosens Bioelectron 2023; 222:114914. [PMID: 36456386 DOI: 10.1016/j.bios.2022.114914] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 10/18/2022] [Accepted: 11/12/2022] [Indexed: 11/18/2022]
Abstract
Inspired by an adaptive immune system, we have developed a bioelectronic sensing platform which relies on nanovesicles for a signal amplification and can be easily adapted for the detection of new food allergens. In this work, nanovesicles with anti-immunoglobulin E (anti-IgE) antibody receptors were extracted from immune cells and immobilized on a carbon nanotube-based transistor to build a highly sensitive and selective biosensing platform. Our sensor could detect peanut allergen, arachis hypogaea 2 (Ara h 2), down to 0.1 fM and selectively discriminate target allergens in real food samples such as peanut and egg white. As a proof of concept, we demonstrated the detection of different target molecules using the same nanovesicles linked with different antibodies. Our sensor platform was also utilized to quantitatively evaluate the effect of allergy drug such as cromolyn. In this regard, our strategy can be utilized for basic research and versatile applications in food and pharmacological industries.
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Affiliation(s)
- Jin-Young Jeong
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - So-Ong Kim
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul, 08826, South Korea
| | - Sunwoo Bang
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Yoonji Choi
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Junghyun Shin
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Danmin Choi
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Sang-Eun Lee
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Tai Hyun Park
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Seoul, 08826, South Korea; Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, 08826, South Korea.
| | - Seunghun Hong
- Department of Physics and Astronomy, and the Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea.
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4
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Suber J, Zhang Y, Ye P, Guo R, Burks AW, Kulis MD, Smith SA, Iweala OI. Novel peanut-specific human IgE monoclonal antibodies enable screens for inhibitors of the effector phase in food allergy. Front Immunol 2022; 13:974374. [PMID: 36248809 PMCID: PMC9556733 DOI: 10.3389/fimmu.2022.974374] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/09/2022] [Indexed: 11/15/2022] Open
Abstract
Background 10% of US residents have food allergies, including 2% with peanut allergy. Mast cell mediators released during the allergy effector phase drive allergic reactions. Therefore, targeting sensitized mast cells may prevent food allergy symptoms. Objective We used novel, human, allergen-specific, IgE monoclonal antibodies (mAbs) created using human hybridoma techniques to design an in vitro system to evaluate potential therapeutics targeting sensitized effector cells. Methods Two human IgE mAbs specific for peanut, generated through human hybridoma techniques, were used to sensitize rat basophilic leukemia (RBL) SX-38 cells expressing the human IgE receptor (FcϵRI). Beta-hexosaminidase release (a marker of degranulation), cytokine production, and phosphorylation of signal transduction proteins downstream of FcϵRI were measured after stimulation with peanut. Degranulation was also measured after engaging inhibitory receptors CD300a and Siglec-8. Results Peanut-specific human IgE mAbs bound FcϵRI, triggering degranulation after stimulation with peanut in RBL SX-38 cells. Sensitized RBL SX-38 cells stimulated with peanut increased levels of phosphorylated SYK and ERK, signal transduction proteins downstream of FcϵRI. Engaging inhibitory cell surface receptors CD300a or Siglec-8 blunted peanut-specific activation. Conclusion Allergen-specific human IgE mAbs, expressed from human hybridomas and specific for a clinically relevant food allergen, passively sensitize allergy effector cells central to the in vitro models of the effector phase of food allergy. Peanut reproducibly activates and induces degranulation of RBL SX-38 cells sensitized with peanut-specific human IgE mAbs. This system provides a unique screening tool to assess the efficacy of therapeutics that target allergy effector cells and inhibit food allergen-induced effector cell activation.
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Affiliation(s)
- Jada Suber
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, United States
- Department of Medicine, Thurston Arthritis Research Center, Division of Rheumatology, Allergy, and Immunology, University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, United States
- Department of Pediatrics, Division of Allergy and Immunology, University of North Carolina Food Allergy Initiative, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Yugen Zhang
- Department of Medicine, Thurston Arthritis Research Center, Division of Rheumatology, Allergy, and Immunology, University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, United States
| | - Ping Ye
- Department of Pediatrics, Division of Allergy and Immunology, University of North Carolina Food Allergy Initiative, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Rishu Guo
- Department of Pediatrics, Division of Allergy and Immunology, University of North Carolina Food Allergy Initiative, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - A. Wesley Burks
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, United States
- Department of Pediatrics, Division of Allergy and Immunology, University of North Carolina Food Allergy Initiative, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Michael D. Kulis
- Department of Pediatrics, Division of Allergy and Immunology, University of North Carolina Food Allergy Initiative, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Scott A. Smith
- Department of Medicine, and Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN, United States
| | - Onyinye I. Iweala
- Department of Medicine, Thurston Arthritis Research Center, Division of Rheumatology, Allergy, and Immunology, University of North Carolina at Chapel Hill (UNC), Chapel Hill, NC, United States
- Department of Pediatrics, Division of Allergy and Immunology, University of North Carolina Food Allergy Initiative, University of North Carolina School of Medicine, Chapel Hill, NC, United States
- *Correspondence: Onyinye I. Iweala,
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Hazebrouck S, Patil SU, Guillon B, Lahood N, Dreskin SC, Adel-Patient K, Bernard H. Immunodominant conformational and linear IgE epitopes lie in a single segment of Ara h 2. J Allergy Clin Immunol 2022; 150:131-139. [PMID: 35150723 PMCID: PMC10440805 DOI: 10.1016/j.jaci.2021.12.796] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 12/16/2021] [Accepted: 12/27/2021] [Indexed: 11/21/2022]
Abstract
BACKGROUND Contribution of conformational epitopes to the IgE reactivity of peanut allergens Ara h 2 and Ara h 6 is at least as important as that of the linear epitopes. However, little is known about these conformational IgE-binding epitopes. OBJECTIVE We investigated the distribution of conformational epitopes on chimeric 2S-albumins. METHODS Recombinant chimeras were generated by exchanging structural segments between Ara h 2 and Ara h 6. Well-refolded chimeras, as verified by circular dichroism analysis, were then used to determine the epitope specificity of mAbs by performing competitive inhibition of IgG binding. Furthermore, we delineated the contribution of each segment to the overall IgE reactivity of both 2S-albumins by measuring the chimeras' IgE-binding capacity with sera from 21 patients allergic to peanut. We finally assessed chimeras' capacity to trigger mast cell degranulation. RESULTS Configuration of the conformational epitopes was preserved in the chimeras. Mouse IgG mAbs, raised against natural Ara h 6, and polyclonal human IgE antibodies recognized different conformational epitopes distributed all along Ara h 6. In contrast, we identified human IgG mAbs specific to different Ara h 2 linear or conformational epitopes located in all segments except the C-terminal one. The major conformational IgE-binding epitope of Ara h 2 was located in a segment located between residues 33 and 81 that also contains the major linear hydroxyproline-containing epitope. Accordingly, this segment is critical for the capacity of Ara h 2 to induce mast cell degranulation. CONCLUSIONS Chimeric 2S-albumins provide new insights on the conformational IgE-binding epitopes of Ara h 2 and Ara h 6. Proximity of the immunodominant linear and conformational IgE-binding epitopes probably contributes to the high allergenic potency of Ara h 2.
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Affiliation(s)
- Stéphane Hazebrouck
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France.
| | - Sarita U Patil
- Department of Medicine, Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, the Food Allergy Center, Massachusetts General Hospital for Children, and Harvard Medical School, Boston, Mass
| | - Blanche Guillon
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
| | - Nicole Lahood
- Department of Medicine, Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital, the Food Allergy Center, Massachusetts General Hospital for Children, and Harvard Medical School, Boston, Mass
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado-Denver, Aurora, Colo
| | - Karine Adel-Patient
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
| | - Hervé Bernard
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
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Hazebrouck S, Canon N, Dreskin SC. The Effector Function of Allergens. FRONTIERS IN ALLERGY 2022; 3:818732. [PMID: 35386644 PMCID: PMC8974742 DOI: 10.3389/falgy.2022.818732] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 01/14/2022] [Indexed: 01/29/2023] Open
Abstract
Allergens are antigens that generate an IgE response (sensitization) in susceptible individuals. The allergenicity of an allergen can be thought of in terms of its ability to sensitize as well as its ability to cross-link IgE/IgE receptor complexes on mast cells and basophils leading to release of preformed and newly formed mediators (effector activity). The identity of the allergens responsible for sensitization may be different from those that elicit an allergic response. Effector activity is determined by (1) the amount of specific IgE (sIgE) and in some circumstances the ratio of sIgE to total IgE, (2) the number of high affinity receptors for IgE (FcεR1) on the cell surface, (3) the affinity of binding of sIgE for its epitope and, in a polyclonal response, the collective avidity, (4) the number and spatial relationships of IgE binding epitopes on the allergen and (5) the presence of IgG that can bind to allergen and either block binding of sIgE and/or activate low affinity IgG receptors that activate intracellular inhibitory pathways. This review will discuss these important immunologic and physical properties that contribute to the effector activity of allergens.
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Affiliation(s)
- Stéphane Hazebrouck
- Université Paris Saclay, CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS), SPI, Gif-sur-Yvette, France
| | - Nicole Canon
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO, United States
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO, United States
- *Correspondence: Stephen C. Dreskin
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Hemmings O, Du Toit G, Radulovic S, Lack G, Santos AF. Ara h 2 is the dominant peanut allergen despite similarities with Ara h 6. J Allergy Clin Immunol 2020; 146:621-630.e5. [PMID: 32298698 PMCID: PMC7482438 DOI: 10.1016/j.jaci.2020.03.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/14/2020] [Accepted: 03/11/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Arachis hypogaea 2 (Ara h 2)-specific IgE is to date the best serologic marker to diagnose peanut allergy. Ara h 6 shares approximately 60% sequence identity and multiple epitopes with Ara h 2. OBJECTIVE Our aim was to assess the diagnostic utility and relative importance of Ara h 2 and Ara h 6 in peanut allergy. METHODS A cohort 100 of children was studied. The cohort included chidren who had peanut allergy, children who were sensitized to but tolerant of peanut, and children who were neither sensitized nor allergic to peanut. Levels of specific IgE to peanut and individual allergens were quantified by using ImmunoCAP. ImmunoCAP inhibition experiments and mast cell activation tests in response to both Ara h 2 and Ara h 6 were performed. Statistical analyses were done using SPSS version 14 and Prism version 7 software. RESULTS Ara h 2-specific IgE and Ara h 6-specific IgE showed the greatest diagnostic accuracy for peanut allergy when compared with specific IgE to peanut and other peanut allergens. Most patients with peanut allergy were sensitized to both Ara h 2 and Ara h 6. Ara h 2 reduced Ara h 2-specific IgE binding more than Ara h 6 did (P < .001), whereas Ara h 6-specific IgE binding was inhibited to a similar degree by Ara h 2 and Ara h 6 (P = .432). In the mast cell activation test, Ara h 2 induced significantly greater maximal reactivity (P = .001) and a lower half maximal effective concentration (P = .002) than did Ara h 6 when testing cosensitized individuals. CONCLUSIONS Ara h 2-specific IgE and Ara h 6-specific IgE provide the greatest accuracy to diagnose peanut allergy. Ara h 2 is the dominant conglutin in peanut allergy in the United Kingdom, despite a degree of cross-reactivity with Ara h 6.
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Affiliation(s)
- Oliver Hemmings
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom
| | - George Du Toit
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom
| | - Suzana Radulovic
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom
| | - Gideon Lack
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom
| | - Alexandra F Santos
- Department of Women and Children's Health (Pediatric Allergy), School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom; Asthma UK Centre in Allergic Mechanisms of Asthma, London, United Kingdom; Children's Allergy Service, Evelina London Children's Hospital, Guy's and St Thomas' Hospital, London, United Kingdom.
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8
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Bernard H, Turner PJ, Ah-Leung S, Ruiz-Garcia M, Clare Mills EN, Adel-Patient K. Circulating Ara h 6 as a marker of peanut protein absorption in tolerant and allergic humans following ingestion of peanut-containing foods. Clin Exp Allergy 2020; 50:1093-1102. [PMID: 32648641 DOI: 10.1111/cea.13706] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/30/2020] [Accepted: 05/29/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Bioaccessibility of food allergens may be a key determinant of allergic reactions. OBJECTIVE To develop a protocol allowing the detection of the major peanut allergen, Ara h 6, in the bloodstream following ingestion of low amounts of peanut and to compare Ara h 6 bioaccessibility by food matrix. We further assessed for differences in absorption in healthy versus peanut-allergic volunteers. METHODS A blood pretreatment combining acidic shock and thermal treatment was developed. This protocol was then applied to blood samples collected from human volunteers (n = 6, healthy controls; n = 14, peanut-allergic patients) at various time-points following ingestion of increasing levels of peanut incurred in different food matrices (cookies, peanut butter and chocolate dessert). Immunodetection was performed using an in-house immunoassay. RESULTS An original pretreatment protocol was optimized, resulting in irreversible dissociation of human antibodies-Ara h 6 immune complex, thus rendering Ara h 6 accessible for its immunodetection. Ara h 6 was detected in samples from all volunteers following ingestion of 300-1000 mg peanut protein, although variations in the kinetics of passage were observed between individuals and matrices. Interestingly, in peanut-allergic subjects, Ara h 6 could be detected following ingestion of lower doses and at higher concentrations than in non-allergic volunteers. CONCLUSIONS AND CLINICAL RELEVANCE The kinetics and intensity of Ara h 6 passage in bloodstream depend on both individual and food matrix. Peanut-allergic patients appear to demonstrate higher absorption rate, the clinical significance of which warrants further evaluation.
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Affiliation(s)
- Hervé Bernard
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS)/ Service de Pharmacologie et d'Immunoanalyse, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Paul J Turner
- Section of Inflammation, Repair & Development, National Heart & Lung Institute, Imperial College London, London, UK
| | - Sandrine Ah-Leung
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS)/ Service de Pharmacologie et d'Immunoanalyse, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Monica Ruiz-Garcia
- Section of Inflammation, Repair & Development, National Heart & Lung Institute, Imperial College London, London, UK
| | - Elizabeth Naomi Clare Mills
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences and Manchester Institute of Biotechnology, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - Karine Adel-Patient
- CEA, INRAE, Département Médicaments et Technologies pour la Santé (DMTS)/ Service de Pharmacologie et d'Immunoanalyse, Université Paris-Saclay, Gif-sur-Yvette, France
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Popp J, Trendelenburg V, Niggemann B, Randow S, Völker E, Vogel L, Reuter A, Spiric J, Schiller D, Beyer K, Holzhauser T. Pea (Pisum sativum) allergy in children: Pis s 1 is an immunodominant major pea allergen and presents IgE binding sites with potential diagnostic value. Clin Exp Allergy 2020; 50:625-635. [PMID: 32078204 DOI: 10.1111/cea.13590] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 02/07/2020] [Accepted: 02/15/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND Food allergy to pea (Pisum sativum) has been rarely studied in children at the clinical and molecular levels. OBJECTIVE To elucidate the allergenic relevance and diagnostic value of pea 7S globulin Pis s 1, nsLTP, and 2S albumins PA1 and PA2 in children. METHODS Children with pea-specific IgE ≥ 0.35 kUA /L and clinical evidence of pea allergy or tolerance were included in the study. IgE binding against pea total protein extract, recombinant (r) rPis s 1, rPA1, rPA2, and natural nsLTP was analysed using IgE immunoblot/inhibition. Mediator release potency was investigated in passively sensitized rat basophil leukaemia (RBL) 2H3-cells. IgE binding to synthetic overlapping peptides of Pis s 1 was detected on multipeptide microarrays. RESULTS 19 pea-sensitized children were included, 14 with doctors' diagnosed allergy and 5 with tolerance to pea (median age 3.5 and 4.5 years, respectively). 11/14 (78%) pea-allergic and 1/5 (20%) tolerant children were sensitized to Pis s 1. Under the reducing conditions of immunoblot analysis, IgE binding to rPA1 was negligible, sensitization to rPA2 and nsLTP undetectable. Compared to pea total protein extract, rPis s 1 displayed on average 58% IgE binding capacity and a 20-fold higher mediator release potency. Selected Pis s 1-related peptides displayed IgE binding in pea-allergic but not in pea-tolerant children. CONCLUSIONS AND CLINICAL RELEVANCE In this study group, Pis s 1 is a major immunodominant allergen in pea-allergic children. Evidence for sensitization to nsLTP and 2S albumins was low but requires further verification with regard to conformational epitopes. Recombinant Pis s 1 and related peptides which were exclusively recognized by pea-allergic children may improve in vitro diagnosis of pea allergy once verified in prospective studies with larger study groups.
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Affiliation(s)
- Jasmin Popp
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - Valérie Trendelenburg
- Department of Pediatric Pulmonology, Immunology and Intensive Care Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Bodo Niggemann
- Department of Pediatric Pulmonology, Immunology and Intensive Care Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Stefanie Randow
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - Elke Völker
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - Lothar Vogel
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - Andreas Reuter
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - Jelena Spiric
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - Dirk Schiller
- Division of Allergology, Paul-Ehrlich-Institut, Langen, Germany
| | - Kirsten Beyer
- Department of Pediatric Pulmonology, Immunology and Intensive Care Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
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Di Stasio L, Tranquet O, Picariello G, Ferranti P, Morisset M, Denery-Papini S, Mamone G. Comparative analysis of eliciting capacity of raw and roasted peanuts: the role of gastrointestinal digestion. Food Res Int 2020; 127:108758. [DOI: 10.1016/j.foodres.2019.108758] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 10/09/2019] [Accepted: 10/14/2019] [Indexed: 01/06/2023]
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11
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Development of hypoallergenic variants of the major horse allergen Equ c 1 for immunotherapy by rational structure based engineering. Sci Rep 2019; 9:20148. [PMID: 31882906 PMCID: PMC6934807 DOI: 10.1038/s41598-019-56812-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/10/2019] [Indexed: 11/25/2022] Open
Abstract
The use of recombinant allergens is a promising approach in allergen-specific immunotherapy (AIT). Considerable limitation, however, has been the ability of recombinant allergens to activate effector cells leading to allergic reactions. Recombinant hypoallergens with preserved protein folding and capacity to induce protective IgG antibodies binding effectively to the native allergen upon sensitization would be beneficial for safer AIT. In this study, hypoallergen variants of the major horse allergen Equ c 1 were designed by introducing one point mutation on the putative IgE epitope region and two mutations on the monomer-monomer interface of Equ c 1 dimer. The recombinant Equ c 1 wild type and the variants were produced and purified to homogeneity, characterized by size-exclusion ultra-high performance liquid chromatography and ultra-high resolution mass spectrometry. The IgE-binding profiles were analyzed by a competitive immunoassay and the biological activity by a histamine release assay using sera from horse allergic individuals. Two Equ c 1 variants, Triple 2 (V47K + V110E + F112K) and Triple 3 (E21Y + V110E + F112K) showed lower allergen-specific IgE-binding capacity and decreased capability to release histamine from basophils in vitro when using sera from six allergic individuals. Triple 3 showed higher reduction than Triple 2 in IgE-binding (5.5 fold) and in histamine release (15.7 fold) compared to wild type Equ c 1. Mutations designed on the putative IgE epitope region and monomer-monomer interface of Equ c 1 resulted in decreased dimerization, a lower IgE-binding capacity and a reduced triggering of an allergic response in vitro.
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12
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Hazebrouck S, Guillon B, Paty E, Dreskin SC, Adel-Patient K, Bernard H. Variable IgE cross-reactivity between peanut 2S-albumins: The case for measuring IgE to both Ara h 2 and Ara h 6. Clin Exp Allergy 2019; 49:1107-1115. [PMID: 31108010 DOI: 10.1111/cea.13432] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/15/2019] [Accepted: 04/25/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND 2S-albumins Ara h 2 and Ara h 6 are the most potent peanut allergens and levels of specific immunoglobulin E (IgE) towards these proteins are good predictors of clinical reactivity. Because of structural homologies, Ara h 6 is generally considered to cross-react extensively with Ara h 2. OBJECTIVE We aimed to quantify the IgE cross-reactivity between Ara h 2 and Ara h 6. METHODS Peanut 2S-albumins were purified from raw peanuts. The IgE cross-reactivity between Ara h 2 and Ara h 6 was evaluated with 32 sera from French and US peanut-allergic patients by measuring the residual IgE-binding to one 2S-albumin after depletion of IgE antibodies recognizing the other 2S-albumin. The IgE cross-reactivity between Ara h 2 and Ara h 6 was further investigated by competitive inhibition of IgE-binding and by a model of mast cell degranulation. RESULTS A highly variable level of IgE cross-reactivity was revealed among the patients. The mean fraction of cross-reactive IgE antibodies represented only 17.1% of 2S-albumins-specific IgE antibodies and was lower than the mean fraction of IgE specific to Ara h 2 (57.4%) or to Ara h 6 (25.5%). The higher level of Ara h 2-specific IgE was principally due to the IgE-binding capacity of an insertion containing the repeated immunodominant linear epitope DPYSPOH S. The impact of IgE cross-reactivity on diagnostic testing was illustrated with a serum displaying an Ara h 6-specific IgE response of 26 UI/mL that was not associated with the capacity of Ara h 6 to trigger mast cell degranulation. CONCLUSIONS & CLINICAL RELEVANCE Immunoglobulin E antibodies specific to peanut 2S-albumins are mainly non-cross-reactive, but low-affinity cross-reactivity can affect diagnostic accuracy. Testing IgE-binding to a mixture of 2S-albumins rather than to each separately may enhance diagnostic performance.
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Affiliation(s)
- Stéphane Hazebrouck
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Blanche Guillon
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Evelyne Paty
- Université Paris Descartes-Assistance Publique des Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, Denver School of Medicine, University of Colorado, Aurora, Colorado
| | - Karine Adel-Patient
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Hervé Bernard
- Service de Pharmacologie et Immunoanalyse (SPI), Laboratoire d'Immuno-Allergie Alimentaire, CEA, INRA, Université Paris-Saclay, Gif-sur-Yvette, France
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13
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Claude M, Lupi R, Picariello G, Drouet M, Larré C, Denery-Papini S, Brossard C. Digestion differently affects the ability of native and thermally aggregated ovalbumin to trigger basophil activation. Food Res Int 2019; 118:108-114. [DOI: 10.1016/j.foodres.2017.11.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/13/2017] [Accepted: 11/19/2017] [Indexed: 01/01/2023]
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14
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Combined microwave processing and enzymatic proteolysis of bovine whey proteins: the impact on bovine β-lactoglobulin allergenicity. Journal of Food Science and Technology 2018; 56:177-186. [PMID: 30728559 DOI: 10.1007/s13197-018-3471-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 10/09/2018] [Accepted: 10/19/2018] [Indexed: 10/27/2022]
Abstract
The main aim of this study was to develop a continuous microwave treatment system of whey proteins and then apply this process at 37 °C, 50 °C, 65 °C and 70 °C to achieve pepsinolysis and produce extensively hydrolysed bovine whey protein hydrolysates with low allergenic properties. The microwave process was compared to a conventional thermal treatment with similar temperature set points. Both processes were deeply analysed in terms of the thermal kinetics and operating conditions. The pepsin hydrolysates obtained by the continuous microwave treatment and conventional heating were characterized by SDS-PAGE and RP-HPLC. The allergenicity of the whey protein hydrolysates was explored using a human IgE sensitized rat basophil leukaemia cell assay. The results indicate that extensively hydrolysed whey protein hydrolysates were obtained by microwave only at 65 °C and in a shorter time compared with the conventional thermal treatment. In the same temperature conditions under conventional heating, β-lactoglobulin was resistant to pepsinolysis, and 37% of it remained intact. As demonstrated by an in vitro degranulation assay using specific human IgE-sensitized rat basophils, the extensively hydrolysed whey protein obtained by microwave showed maximum degranulation values of 6.53% compared to those of the native whey protein isolate (45.97%) and hence elicited no more allergenic reactions in basophils. This work emphasizes the potential industrial use of microwave heating specific to milk protein processing to reduce their allergenicity and improve their end-use properties.
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15
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Bahri R, Custovic A, Korosec P, Tsoumani M, Barron M, Wu J, Sayers R, Weimann A, Ruiz-Garcia M, Patel N, Robb A, Shamji MH, Fontanella S, Silar M, Mills ENC, Simpson A, Turner PJ, Bulfone-Paus S. Mast cell activation test in the diagnosis of allergic disease and anaphylaxis. J Allergy Clin Immunol 2018. [PMID: 29518421 PMCID: PMC6075471 DOI: 10.1016/j.jaci.2018.01.043] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background Food allergy is an increasing public health issue and the most common cause of life-threatening anaphylactic reactions. Conventional allergy tests assess for the presence of allergen-specific IgE, significantly overestimating the rate of true clinical allergy and resulting in overdiagnosis and adverse effect on health-related quality of life. Objective To undertake initial validation and assessment of a novel diagnostic tool, we used the mast cell activation test (MAT). Methods Primary human blood-derived mast cells (MCs) were generated from peripheral blood precursors, sensitized with patients' sera, and then incubated with allergen. MC degranulation was assessed by means of flow cytometry and mediator release. We compared the diagnostic performance of MATs with that of existing diagnostic tools to assess in a cohort of peanut-sensitized subjects undergoing double-blind, placebo-controlled challenge. Results Human blood-derived MCs sensitized with sera from patients with peanut, grass pollen, and Hymenoptera (wasp venom) allergy demonstrated allergen-specific and dose-dependent degranulation, as determined based on both expression of surface activation markers (CD63 and CD107a) and functional assays (prostaglandin D2 and β-hexosaminidase release). In this cohort of peanut-sensitized subjects, the MAT was found to have superior discrimination performance compared with other testing modalities, including component-resolved diagnostics and basophil activation tests. Using functional principle component analysis, we identified 5 clusters or patterns of reactivity in the resulting dose-response curves, which at preliminary analysis corresponded to the reaction phenotypes seen at challenge. Conclusion The MAT is a robust tool that can confer superior diagnostic performance compared with existing allergy diagnostics and might be useful to explore differences in effector cell function between basophils and MCs during allergic reactions.
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Affiliation(s)
- Rajia Bahri
- Division of Musculoskeletal and Dermatological Sciences & Manchester Collaborative Centre for Inflammation Research (MCCIR), School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Adnan Custovic
- Section of Paediatrics, Department of Medicine, Imperial College London, London, United Kingdom
| | - Peter Korosec
- Laboratory for Clinical Immunology & Molecular Genetics, University Hospital for Respiratory and Allergic Diseases, Golnik, Slovenia
| | - Marina Tsoumani
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, University of Manchester, and NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Martin Barron
- Division of Musculoskeletal and Dermatological Sciences & Manchester Collaborative Centre for Inflammation Research (MCCIR), School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Jiakai Wu
- Division of Musculoskeletal and Dermatological Sciences & Manchester Collaborative Centre for Inflammation Research (MCCIR), School of Biological Sciences, University of Manchester, Manchester, United Kingdom
| | - Rebekah Sayers
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, University of Manchester, and NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | | | - Monica Ruiz-Garcia
- Section of Paediatrics, Department of Medicine, Imperial College London, London, United Kingdom
| | - Nandinee Patel
- Section of Paediatrics, Department of Medicine, Imperial College London, London, United Kingdom
| | - Abigail Robb
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, University of Manchester, and NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Mohamed H Shamji
- Section of Allergy and Clinical Immunology, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Sara Fontanella
- Section of Paediatrics, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mira Silar
- Laboratory for Clinical Immunology & Molecular Genetics, University Hospital for Respiratory and Allergic Diseases, Golnik, Slovenia
| | - E N Clare Mills
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, University of Manchester, and NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Angela Simpson
- Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, University of Manchester, and NIHR Manchester Biomedical Research Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Paul J Turner
- Section of Paediatrics, Department of Medicine, Imperial College London, London, United Kingdom.
| | - Silvia Bulfone-Paus
- Division of Musculoskeletal and Dermatological Sciences & Manchester Collaborative Centre for Inflammation Research (MCCIR), School of Biological Sciences, University of Manchester, Manchester, United Kingdom.
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Falcone FH, Wan D, Barwary N, Sagi-Eisenberg R. RBL cells as models for in vitro studies of mast cells and basophils. Immunol Rev 2018; 282:47-57. [DOI: 10.1111/imr.12628] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Franco H. Falcone
- Division of Molecular Therapeutics and Formulation; School of Pharmacy; University of Nottingham; Nottingham UK
| | - Daniel Wan
- Division of Molecular Therapeutics and Formulation; School of Pharmacy; University of Nottingham; Nottingham UK
| | - Nafal Barwary
- Division of Molecular Therapeutics and Formulation; School of Pharmacy; University of Nottingham; Nottingham UK
| | - Ronit Sagi-Eisenberg
- Department of Cell and Developmental Biology; Sackler Faculty of Medicine; Tel Aviv University; Tel Aviv Israel
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17
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Lupi R, Denery-Papini S, Claude M, Tranquet O, Drouet M, Masci S, Larré C. Thermal treatment reduces gliadin recognition by IgE, but a subsequent digestion and epithelial crossing permits recovery. Food Res Int 2018; 118:22-31. [PMID: 30898348 DOI: 10.1016/j.foodres.2018.02.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/19/2018] [Accepted: 02/02/2018] [Indexed: 01/01/2023]
Abstract
Wheat is one of the most important crops in the world in terms of human nutrition. With regards to health, some individuals exhibit wheat-related disorders such as food allergy to wheat (FAW). In this disorder, gluten is involved, particularly the gliadins which are among the main proteins responsible for FAW. Food processing, as well as digestibility and intestinal transport are key factors to consider since they may affect the allergenic potential of food allergens. Wheat is always consumed after heat processing and this step may impact epitope accessibility by inducing aggregation and may irreversibly destroy conformational epitopes. Our aim was to investigate the effects of heating and digestion on the structure of well-known allergens (total gliadins and α-gliadins) and their capacity to maintain their allergenic potential after crossing an intestinal barrier. The sizes of the processed (heated and heated/digested) proteins were characterized by laser light scattering and chromatographic reverse phase. The IgE-binding capacities of native and processed proteins were checked using a dot blot with sera from wheat allergenic patients. Furthermore, the abilities of these samples to cross the intestinal barrier and to induce mast cell degranulation were investigated by combining two in vitro cellular models, Caco-2 and RBL-SX38. The heat treatment of total gliadins and α-gliadins induced the production of large aggregates that were hardly recognized by IgE of patients in dot-blot. However, after limited pepsin hydrolysis, the epitopes were unmasked, and they were able to bind IgE again. Native proteins (gliadins and α-type) and processed forms were able to cross the Caco-2 cells in small amount. Permeability studies revealed the capacity of α-gliadins to increase paracellular permeability. In the RBL assay, the total native gliadins were able to trigger cell degranulation, but none of their processed forms. However after crossing the CaCo-2 monolayer, processed gliadins recovered their degranulation capacity to a certain extent. Total native gliadins remained the best allergenic form compared to α-type.
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Affiliation(s)
- R Lupi
- University of Tuscia, Department of Agricultural and Forestry Science, Via S. Camillo de Lellis s.n.c., 01100 Viterbo, Italy; INRA, UR 1268 Biopolymers Interactions Assemblies, 44316 Nantes, France.
| | - S Denery-Papini
- INRA, UR 1268 Biopolymers Interactions Assemblies, 44316 Nantes, France.
| | - M Claude
- INRA, UR 1268 Biopolymers Interactions Assemblies, 44316 Nantes, France
| | - O Tranquet
- INRA, UR 1268 Biopolymers Interactions Assemblies, 44316 Nantes, France.
| | - M Drouet
- CHU d'Angers, Unité Allergologie Générale, F-49000 Angers, France.
| | - S Masci
- University of Tuscia, Department of Agricultural and Forestry Science, Via S. Camillo de Lellis s.n.c., 01100 Viterbo, Italy.
| | - C Larré
- INRA, UR 1268 Biopolymers Interactions Assemblies, 44316 Nantes, France.
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18
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19
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Conformational stability of digestion-resistant peptides of peanut conglutins reveals the molecular basis of their allergenicity. Sci Rep 2016; 6:29249. [PMID: 27377129 PMCID: PMC4932508 DOI: 10.1038/srep29249] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 06/13/2016] [Indexed: 12/14/2022] Open
Abstract
Conglutins represent the major peanut allergens and are renowned for their resistance to gastro-intestinal digestion. Our aim was to characterize the digestion-resistant peptides (DRPs) of conglutins by biochemical and biophysical methods followed by a molecular dynamics simulation in order to better understand the molecular basis of food protein allergenicity. We have mapped proteolysis sites at the N- and C-termini and at a limited internal segment, while other potential proteolysis sites remained unaffected. Molecular dynamics simulation showed that proteolysis only occurred in the vibrant regions of the proteins. DRPs appeared to be conformationally stable as intact conglutins. Also, the overall secondary structure and IgE-binding potency of DRPs was comparable to that of intact conglutins. The stability of conglutins toward gastro-intestinal digestion, combined with the conformational stability of the resulting DRPs provide conditions for optimal exposure to the intestinal immune system, providing an explanation for the extraordinary allergenicity of peanut conglutins.
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20
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Deak PE, Vrabel MR, Pizzuti VJ, Kiziltepe T, Bilgicer B. Nanoallergens: A multivalent platform for studying and evaluating potency of allergen epitopes in cellular degranulation. Exp Biol Med (Maywood) 2016; 241:996-1006. [PMID: 27188517 DOI: 10.1177/1535370216644533] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Degranulation caused by type I hypersensitivity (allergies) is a complex biophysical process, and available experimental models for studying relevant immunoglobulin E binding epitopes on allergen proteins lack the ability to adequately evaluate, rank, and associate these epitopes individually and with each other. In this study, we propose a new allergy model system for studying potential allergen epitopes using nanoallergens, liposomes modified to effectively display IgE binding epitopes/haptens. By utilizing the covalently conjugated lipid tails on two hapten molecules (dinitrophenol and dansyl), hapten molecules were successfully incorporated into liposomes with high precision to form nanoallergens. Nanoallergens, with precisely controlled high-particle valency, can trigger degranulation with much greater sensitivity than commonly used bovine serum albumin conjugates. In rat basophil leukemia cell experiments, nanoallergens with only 2% hapten loading were able to trigger degranulation in vitro at concentrations as low as 10 pM. Additionally, unlike bovine serum albumin-hapten conjugates, nanoallergens allow exact control over particle size and valency. By varying the nanoallergen parameters such as size, valency, monovalent affinity of hapten, and specific IgE ratios, we exposed the importance of these variables on degranulation intensity while demonstrating nanoallergens' potential for evaluating both high- and low-affinity epitopes. The data presented in this article establish nanoallergen platform as a reliable and versatile allergy model to study and evaluate allergen epitopes in mast cell degranulation.
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Affiliation(s)
- Peter E Deak
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, IN 46556, USA
| | - Maura R Vrabel
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, IN 46556, USA
| | - Vincenzo J Pizzuti
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, IN 46556, USA
| | - Tanyel Kiziltepe
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, IN 46556, USA Advanced Diagnostics and Therapeutics, University of Notre Dame, IN 46556, USA
| | - Basar Bilgicer
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, IN 46556, USA Advanced Diagnostics and Therapeutics, University of Notre Dame, IN 46556, USA Department of Chemistry and Biochemistry, University of Notre Dame, IN 46556, USA
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21
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Claude M, Lupi R, Bouchaud G, Bodinier M, Brossard C, Denery-Papini S. The thermal aggregation of ovalbumin as large particles decreases its allergenicity for egg allergic patients and in a murine model. Food Chem 2016; 203:136-144. [PMID: 26948598 DOI: 10.1016/j.foodchem.2016.02.054] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/14/2016] [Accepted: 02/09/2016] [Indexed: 01/05/2023]
Abstract
Most egg-allergic children can tolerate extensively cooked eggs. Ovalbumin, a major allergen in egg whites, is prone to aggregate upon heating. This study compares ovalbumin's allergenicity when it is aggregated as large particles to ovalbumin in its native form. Immunoglobulins (Ig)-binding and the degranulation capacities of native and aggregated ovalbumin were measured with sera from egg-allergic children and from mice sensitized to native or aggregated ovalbumin. The influence of ovalbumin structure on Ig production upon sensitization and elicitation potency by challenge was also studied. We showed that heat aggregation of ovalbumin as large particles enhances IgG production and promotes IgG2a production (a shift toward the T helper 1 profile). Aggregated ovalbumin displayed lower Ig-binding and basophil-activation capacities for sera from both allergic patients and mice. This work illustrates the links between ovalbumin structure after heating and allergenicity potential using parameters from both the sensitization and elicitation phases of the allergic reaction.
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Affiliation(s)
- M Claude
- INRA, UR 1268 BIA (Biopolymers, Interactions, Assemblies), F-44316, rue de la Géraudière, 44316 Nantes, France
| | - R Lupi
- INRA, UR 1268 BIA (Biopolymers, Interactions, Assemblies), F-44316, rue de la Géraudière, 44316 Nantes, France
| | - G Bouchaud
- INRA, UR 1268 BIA (Biopolymers, Interactions, Assemblies), F-44316, rue de la Géraudière, 44316 Nantes, France
| | - M Bodinier
- INRA, UR 1268 BIA (Biopolymers, Interactions, Assemblies), F-44316, rue de la Géraudière, 44316 Nantes, France
| | - C Brossard
- INRA, UR 1268 BIA (Biopolymers, Interactions, Assemblies), F-44316, rue de la Géraudière, 44316 Nantes, France.
| | - S Denery-Papini
- INRA, UR 1268 BIA (Biopolymers, Interactions, Assemblies), F-44316, rue de la Géraudière, 44316 Nantes, France
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22
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Mihajlovic L, Radosavljevic J, Nordlund E, Krstic M, Bohn T, Smit J, Buchert J, Cirkovic Velickovic T. Peanut protein structure, polyphenol content and immune response to peanut proteins in vivo are modulated by laccase. Food Funct 2016; 7:2357-66. [DOI: 10.1039/c5fo01325a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Laccase cross-linking of peanut protein causes changes in the protein structure, phenolic composition and immunological properties of the treated peanut protein.
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Affiliation(s)
- L. Mihajlovic
- University of Belgrade
- Faculty of Chemistry
- Belgrade
- Serbia
| | | | | | - M. Krstic
- University of Belgrade
- Faculty of Chemistry
- Belgrade
- Serbia
| | - T. Bohn
- Centre de Recherche Public – Gabriel Lippmann
- Belvaux
- Luxembourg
| | - J. Smit
- Institute for Risk Assessment Sciences
- Utrecht University
- Utrecht
- Netherlands
| | - J. Buchert
- National Food Resources Institute (Luke)
- Helsinki
- Finland
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Namork E, Stensby BA. Peanut sensitization pattern in Norwegian children and adults with specific IgE to peanut show age related differences. Allergy Asthma Clin Immunol 2015; 11:32. [PMID: 26568764 PMCID: PMC4644336 DOI: 10.1186/s13223-015-0095-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/03/2015] [Indexed: 11/23/2022] Open
Abstract
Background Peanuts contain potent food allergens and the prevalence of allergy is reported to increase, especially in children. Since peanut sensitization may differ between different geographical regions, we wanted to investigate the sensitization pattern to the individual peanut allergens in a Norwegian population. Methods Cases reported to the Norwegian Food Allergy Register with sera positive to peanut extract were analyzed for specific IgE (sIgE) to the recombinant peanut allergens Ara h 1, Ara h 2, Ara h 3, Ara h 8 and Ara h 9 and to birch pollen extract. Serum samples negative to the above allergens were analyzed for sIgE to Ara h 6, and sIgE to Pru p 3 in peach were analyzed in sera positive to the cross-reactive allergen Ara h 9. Results Highest frequency of sIgE to Ara h 2, often co-sensitized to Ara h 1 and 3, were found in the small children up to 6 years of age. From the age of 6 years, sensitization to Ara h 8 was predominant. The sIgE levels to the storage proteins Ara h 1, 2 and 3 were strongly correlated, as was the sIgE levels to Ara h 8 and birch pollen extract. A low sensitization rate of sIgE to Ara h 9 in young adults was observed, which sIgE levels were very strongly correlated to Pru p 3. Conclusion The sensitization to peanut allergens in a Norwegian population shows a clear age dependent pattern. The results add to the previously published research on the sensitization patterns of peanut sensitized patients in different geographical areas.
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Affiliation(s)
- Ellen Namork
- Division of Environmental Medicine, Department of Food, Water and Cosmetics, Norwegian Institute of Public Health, PO Box 4404, 0403 Oslo, Norway ; Lovisenberggata 8, Oslo, Norway
| | - Berit A Stensby
- Division of Environmental Medicine, Department of Food, Water and Cosmetics, Norwegian Institute of Public Health, PO Box 4404, 0403 Oslo, Norway
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Otsu K, Guo R, Dreskin SC. Epitope analysis of Ara h 2 and Ara h 6: characteristic patterns of IgE-binding fingerprints among individuals with similar clinical histories. Clin Exp Allergy 2015; 45:471-84. [PMID: 25213872 DOI: 10.1111/cea.12407] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 07/15/2014] [Accepted: 08/14/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Ara h 2 and Ara h 6 are moderately homologous and highly potent peanut allergens. OBJECTIVE To identify IgE-binding linear epitopes of Ara h 6, compare them to those of Ara h 2, and to stratify binding based on clinical histories. METHODS Thirty highly peanut-allergic subjects were stratified by clinical history. Sera were diluted to contain the same amount of anti-peanut IgE. IgE binding to overlapping 20-mer peptides of Ara h 2 and Ara h 6 was assessed using microarrays. RESULTS Each subject had a unique IgE-binding fingerprint to peptides; these data were coalesced into epitope binding. IgE from subjects with a history of more severe reactions (n = 19) had a smaller frequency of binding events (BEs) for both Ara h 2 (52 BEs of 152 (19X8epitopes) possible BEs and Ara h 6 (13 BEs of 133 (19X7 epitopes) possible BEs) compared to IgE from those with milder histories (n = 11) (Ara h 2: 47 BEs of 88 (11X8 epitopes) possible BEs, P < 0.01; Ara h 6: 25 BEs of 77 (11X7 epitopes) possible BEs, P < 0.001). Using an unsupervised hierarchal cluster analysis, subjects with similar histories tended to cluster. We have tentatively identified a high-risk pattern of binding to peptides of Ara h 2 and Ara h 6, predominantly in subjects with a history of more severe reactions (OR = 12.6; 95% CI: 2.0-79.5; P < 0.01). CONCLUSIONS AND CLINICAL RELEVANCE IgE from patients with more severe clinical histories recognize fewer linear epitopes of Ara h 2 and Ara h 6 than do subjects with milder reactions and bind these epitopes in characteristic patterns. Close examination of IgE binding to epitopes of Ara h 2 and Ara h 6 may have prognostic value.
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Affiliation(s)
- K Otsu
- Division of Allergy and Clinical Immunology and Departments of Medicine and Immunology, University of Colorado Denver, Aurora, CO, USA
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IgG4 inhibits peanut-induced basophil and mast cell activation in peanut-tolerant children sensitized to peanut major allergens. J Allergy Clin Immunol 2015; 135:1249-56. [PMID: 25670011 PMCID: PMC4418748 DOI: 10.1016/j.jaci.2015.01.012] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 01/26/2015] [Accepted: 01/26/2015] [Indexed: 12/24/2022]
Abstract
Background Most children with detectable peanut-specific IgE (P-sIgE) are not allergic to peanut. We addressed 2 non–mutually exclusive hypotheses for the discrepancy between allergy and sensitization: (1) differences in P-sIgE levels between children with peanut allergy (PA) and peanut-sensitized but tolerant (PS) children and (2) the presence of an IgE inhibitor, such as peanut-specific IgG4 (P-sIgG4), in PS patients. Methods Two hundred twenty-eight children (108 patients with PA, 77 PS patients, and 43 nonsensitized nonallergic subjects) were studied. Levels of specific IgE and IgG4 to peanut and its components were determined. IgE-stripped basophils or a mast cell line were used in passive sensitization activation and inhibition assays. Plasma of PS subjects and patients submitted to peanut oral immunotherapy (POIT) were depleted of IgG4 and retested in inhibition assays. Results Basophils and mast cells sensitized with plasma from patients with PA but not PS patients showed dose-dependent activation in response to peanut. Levels of sIgE to peanut and its components could only partially explain differences in clinical reactivity between patients with PA and PS patients. P-sIgG4 levels (P = .023) and P-sIgG4/P-sIgE (P < .001), Ara h 1–sIgG4/Ara h 1–sIgE (P = .050), Ara h 2–sIgG4/Ara h 2–sIgE (P = .004), and Ara h 3–sIgG4/Ara h 3–sIgE (P = .016) ratios were greater in PS children compared with those in children with PA. Peanut-induced activation was inhibited in the presence of plasma from PS children with detectable P-sIgG4 levels and POIT but not from nonsensitized nonallergic children. Depletion of IgG4 from plasma of children with PS (and POIT) sensitized to Ara h 1 to Ara h 3 partially restored peanut-induced mast cell activation (P = .007). Conclusions Differences in sIgE levels and allergen specificity could not justify the clinical phenotype in all children with PA and PS children. Blocking IgG4 antibodies provide an additional explanation for the absence of clinical reactivity in PS patients sensitized to major peanut allergens.
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Abstract
Peanut allergy is common and can be a cause of severe, life-threatening reactions. It is rarely outgrown like other food allergies such as egg and milk. Measures aiming to reduce its prevalence via maternal avoidance during pregnancy and lactation, or delayed introduction into the diet, have failed to show any benefit. Peanut allergy has a significant effect on the quality of life of sufferers and their families due to dietary and social restrictions, but mainly stemming from fear of accidental peanut ingestion. The current management consists of strict avoidance, education and provision of emergency medication. Families find avoidance challenging as peanut is hidden in various food products. Despite the fact that food labelling has improved, with a legal obligation to declare certain food allergens (including nuts) in prepacked products, it still causes confusion and does not extend to cross-contamination. In an effort to address issues of safety at school, a lot of work has been undertaken to better care for peanut-allergic children in that environment. This includes training of school staff on how to recognise and treat allergic reactions promptly. Recent developments in the management of peanut allergy, such as immunotherapy, have shown some promise as an active form of treatment, but larger studies are required to further investigate safety and efficacy.
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Affiliation(s)
- Katherine Anagnostou
- Department of Paediatric Allergy, Guy's and St Thomas' Hospitals NHS Foundation Trust, London, UK
| | - Andrew Clark
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
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Hazebrouck S, Ah-Leung S, Bidat E, Paty E, Drumare MF, Tilleul S, Adel-Patient K, Wal JM, Bernard H. Goat's milk allergy without cow's milk allergy: suppression of non-cross-reactive epitopes on caprine β-casein. Clin Exp Allergy 2014; 44:602-10. [PMID: 24372684 DOI: 10.1111/cea.12261] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/30/2013] [Accepted: 12/16/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE Goat's milk (GM) allergy associated with tolerance to cow's milk (CM) has been reported in patients without history of CM allergy and in CM-allergic children successfully treated with oral immunotherapy. The IgE antibodies from GM-allergic/CM-tolerant patients recognize caprine β-casein (βcap) without cross-reacting with bovine β-casein (βbov) despite a sequence identity of 91%. In this study, we investigated the non-cross-reactive IgE-binding epitopes of βcap. METHODS Recombinant βcap was genetically modified by substituting caprine domains with the bovine counterparts and by performing site-directed mutagenesis. We then evaluated the recognition of modified βcap by IgE antibodies from 11 GM-allergic/CM-tolerant patients and 11 CM-allergic patients or by monoclonal antibodies (mAb) raised against caprine caseins. The allergenic potency of modified βcap was finally assessed by degranulation tests of humanized rat basophil leukaemia (RBL)-SX38 cells. RESULTS Non-cross-reactive epitopes of βcap were found in domains 44-88 and 130-178. The substitutions A55T/T63P/L75P and P148H/S152P induced the greatest decrease in IgE reactivity of GM-allergic/CM-tolerant patients towards βcap. The pivotal role of threonine 63 was particularly revealed as its substitution also impaired the recognition of βcap by specific mAb, which could discriminate between βcap and βbov. The modified βcap containing the five substitutions was then unable to trigger the degranulation of RBL-SX38 cells passively sensitized with IgE antibodies from GM-allergic/CM-tolerant patients. CONCLUSIONS Although IgE-binding epitopes are spread all over βcap, a non-cross-linking version of βcap was generated with only five amino acid substitutions and could thus provide new insight for the design of hypoallergenic variants.
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Affiliation(s)
- S Hazebrouck
- INRA, UR 496, Unité d'Immuno-Allergie Alimentaire, CEA/iBiTeC-S/SPI, Gif-sur-Yvette, France
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Bernard H, Guillon B, Drumare MF, Paty E, Dreskin SC, Wal JM, Adel-Patient K, Hazebrouck S. Allergenicity of peanut component Ara h 2: Contribution of conformational versus linear hydroxyproline-containing epitopes. J Allergy Clin Immunol 2014; 135:1267-74.e1-8. [PMID: 25483599 DOI: 10.1016/j.jaci.2014.10.025] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 10/03/2014] [Accepted: 10/06/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND The 2S-albumin Ara h 2 is the most potent peanut allergen and a good predictor of clinical reactivity in allergic children. Posttranslational hydroxylation of proline residues occurs in DPYSP(OH)S motifs, which are repeated 2 or 3 times in different isoforms. OBJECTIVES We investigated the effect of proline hydroxylation on IgE binding and the relative contributions of linear and conformational epitopes to Ara h 2 allergenicity. METHODS Peptides containing DPYSP(OH)S motifs were synthesized. A recombinant variant of Ara h 2 without DPYSP(OH)S motifs was generated by means of deletion mutagenesis. IgE reactivity of 18 French and 5 American patients with peanut allergy toward synthetic peptides and recombinant allergens was assessed by using IgE-binding inhibition assays and degranulation tests of humanized rat basophilic leukemia cells. RESULTS Hydroxyproline-containing peptides exhibited an IgE-binding activity equivalent to that of the unfolded Ara h 2. In contrast, corresponding peptides without hydroxyprolines displayed a very weak IgE-binding capacity. Despite removal of the DPYSP(OH)S motifs, the deletion variant still displayed Ara h 2 conformational epitopes. The IgE-binding capacity of Ara h 2 was then recapitulated with an equimolar mixture of a hydroxylated peptide and the deletion variant. Hydroxylated peptides of 15 and 27 amino acid residues were also able to trigger cell degranulation. CONCLUSIONS Sensitization toward linear and conformational epitopes of Ara h 2 is variable among patients with peanut allergy. Optimal IgE binding to linear epitopes of Ara h 2 requires posttranslational hydroxylation of proline residues. The absence of hydroxyprolines could then affect the accuracy of component-resolved diagnostics by using rAra h 2.
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Affiliation(s)
- Hervé Bernard
- INRA, UR 496, Unité d'Immuno-Allergie Alimentaire, Jouy-en-Josas, France; CEA, iBiTecS/Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Blanche Guillon
- INRA, UR 496, Unité d'Immuno-Allergie Alimentaire, Jouy-en-Josas, France; CEA, iBiTecS/Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Marie-Françoise Drumare
- INRA, UR 496, Unité d'Immuno-Allergie Alimentaire, Jouy-en-Josas, France; CEA, iBiTecS/Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Evelyne Paty
- Université Paris Descartes-Assistance Publique des Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, Colo
| | - Jean-Michel Wal
- INRA, UR 496, Unité d'Immuno-Allergie Alimentaire, Jouy-en-Josas, France; CEA, iBiTecS/Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Karine Adel-Patient
- INRA, UR 496, Unité d'Immuno-Allergie Alimentaire, Jouy-en-Josas, France; CEA, iBiTecS/Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France
| | - Stéphane Hazebrouck
- INRA, UR 496, Unité d'Immuno-Allergie Alimentaire, Jouy-en-Josas, France; CEA, iBiTecS/Service de Pharmacologie et d'Immunoanalyse, Gif-sur-Yvette, France.
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Bernard H, Ah-Leung S, Drumare MF, Feraudet-Tarisse C, Verhasselt V, Wal JM, Créminon C, Adel-Patient K. Peanut allergens are rapidly transferred in human breast milk and can prevent sensitization in mice. Allergy 2014; 69:888-97. [PMID: 24773443 DOI: 10.1111/all.12411] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2014] [Indexed: 12/29/2022]
Abstract
BACKGROUND Food allergens have been evidenced in breast milk under physiological conditions, but the kinetic and the role of this passage in food allergies are still unclear. We then aimed to analyze the passage of peanut allergens in human breast milk and their allergenicity/immunomodulatory properties. METHODS Human breast milk was collected from two non-atopic peanut-tolerant mothers before and at different time points after ingestion of 30 g of commercial roasted peanut. Ara h 6, Ara h 6 immune complexes, and the IgE binding capacity of breast milk samples were measured using specific immunoassays. Their allergenic functionality was then assessed using cell-based assay. Finally, human breast milk obtained before or after peanut ingestion was administered intragastrically to BALB/c mice at different ages, and mice were further experimentally sensitized to peanut using cholera toxin. RESULTS Ara h 6 is detected as soon as 10 min after peanut ingestion, with peak values observed within the first hour after ingestion. The transfer is long-lasting, small quantities of peanut allergens being detected over a 24-h period. IgG-Ara h 6 and IgA-Ara h 6 immune complexes are evidenced, following a different kinetic of excretion than free allergens. Peanut allergens transferred in milk are IgE reactive and can induce an allergic reaction in vitro. However, administration of human breast milk to young mice, notably before weaning, does not lead to sensitization, but instead to partial oral tolerance. CONCLUSION The low quantities of immunologically active allergens transferred through breast milk may prevent instead of priming allergic sensitization to peanut.
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Affiliation(s)
- H. Bernard
- INRA; UR496 Unité d'Immuno-Allergie Alimentaire; Jouy-en-Josas France
- CEA; IBiTecS; Service de Pharmacologie et d'Immunoanalyse; Gif-sur-Yvette France
| | - S. Ah-Leung
- INRA; UR496 Unité d'Immuno-Allergie Alimentaire; Jouy-en-Josas France
- CEA; IBiTecS; Service de Pharmacologie et d'Immunoanalyse; Gif-sur-Yvette France
| | - M.-F. Drumare
- INRA; UR496 Unité d'Immuno-Allergie Alimentaire; Jouy-en-Josas France
- CEA; IBiTecS; Service de Pharmacologie et d'Immunoanalyse; Gif-sur-Yvette France
| | - C. Feraudet-Tarisse
- CEA; IBiTecS; Service de Pharmacologie et d'Immunoanalyse; Gif-sur-Yvette France
| | - V. Verhasselt
- EA 6302 Tolérance Immunitaire; Hôpital de l'Archet; Université de Nice Sophia-Antipolis; Nice France
| | - J.-M. Wal
- INRA; UR496 Unité d'Immuno-Allergie Alimentaire; Jouy-en-Josas France
- CEA; IBiTecS; Service de Pharmacologie et d'Immunoanalyse; Gif-sur-Yvette France
| | - C. Créminon
- CEA; IBiTecS; Service de Pharmacologie et d'Immunoanalyse; Gif-sur-Yvette France
| | - K. Adel-Patient
- INRA; UR496 Unité d'Immuno-Allergie Alimentaire; Jouy-en-Josas France
- CEA; IBiTecS; Service de Pharmacologie et d'Immunoanalyse; Gif-sur-Yvette France
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Sun N, Zhou C, Zhou X, Sun L, Che H. Use of a rat basophil leukemia (RBL) cell-based immunological assay for allergen identification, clinical diagnosis of allergy, and identification of anti-allergy agents for use in immunotherapy. J Immunotoxicol 2014; 12:199-205. [PMID: 24920006 DOI: 10.3109/1547691x.2014.920063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Food allergy is an important public health problem that affects an estimated 8% of young children and 2% of adults. With an increasing interest in genetically-engineered foods, there is a growing need for development of sensitive and specific tests to evaluate potential allergenicity of foods and novel proteins as well as to determine allergic responses to ensure consumer safety. This review covers progress made in the field of development of cell models, specifically that involving a rat basophil leukemia (RBL) cell-based immunoassay, for use in allergen identification, diagnosis, and immunotherapy. The RBL assay has been extensively employed for determining biologically relevant cross-reactivities of food proteins, assessing the effect of processing on the allergenicity of food proteins, diagnosing allergic responses to whole-food products, and identifying anti-allergy food compounds. From the review of the literature, one might conclude the RBL cell-based assay is a better test system when compared to wild-type mast cell and basophil model systems for use in allergen identification, diagnosis, and analyses of potential immunotherapeutics. However, it is important to emphasize that this assay will only be able to identify those allergens to which the human has already been exposed, but will not identify a truly novel allergen, i.e. one that has never been encountered as in its preferred (humanized) configuration.
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Affiliation(s)
- Na Sun
- College of Food Science and Nutritional Engineering, China Agricultural University , Beijing , PR China and
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Kroghsbo S, Rigby NM, Johnson PE, Adel-Patient K, Bøgh KL, Salt LJ, Mills ENC, Madsen CB. Assessment of the sensitizing potential of processed peanut proteins in Brown Norway rats: roasting does not enhance allergenicity. PLoS One 2014; 9:e96475. [PMID: 24805813 PMCID: PMC4013017 DOI: 10.1371/journal.pone.0096475] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 04/08/2014] [Indexed: 11/29/2022] Open
Abstract
Background IgE-binding of process-modified foods or proteins is the most common method for examination of how food processing affects allergenicity of food allergens. How processing affects sensitization capacity is generally studied by administration of purified food proteins or food extracts and not allergens present in their natural food matrix. Objectives The aim was to investigate if thermal processing increases sensitization potential of whole peanuts via the oral route. In parallel, the effect of heating on sensitization potential of the major peanut allergen Ara h 1 was assessed via the intraperitoneal route. Methods Sensitization potential of processed peanut products and Ara h 1 was examined in Brown Norway (BN) rats by oral administration of blanched or oil-roasted peanuts or peanut butter or by intraperitoneal immunization of purified native (N-), heated (H-) or heat glycated (G-)Ara h 1. Levels of specific IgG and IgE were determined by ELISA and IgE functionality was examined by rat basophilic leukemia (RBL) cell assay. Results In rats dosed orally, roasted peanuts induced significant higher levels of specific IgE to NAra h 1 and 2 than blanched peanuts or peanut butter but with the lowest level of RBL degranulation. However, extract from roasted peanuts was found to be a superior elicitor of RBL degranulation. Process-modified Ara h 1 had similar sensitizing capacity as NAra h 1 but specific IgE reacted more readily with process-modified Ara h 1 than with native. Conclusions Peanut products induce functional specific IgE when dosed orally to BN rats. Roasted peanuts do not have a higher sensitizing capacity than blanched peanuts. In spite of this, extract from roasted peanuts is a superior elicitor of RBL cell degranulation irrespectively of the peanut product used for sensitization. The results also suggest that new epitopes are formed or disclosed by heating Ara h 1 without glucose.
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Affiliation(s)
- Stine Kroghsbo
- National Food Institute, Technical University of Denmark, Søborg, Denmark
| | - Neil M. Rigby
- Institute of Food Research, Norwich Research Park, Colney, Norwich, United Kingdom
| | - Philip E. Johnson
- Institute of Food Research, Norwich Research Park, Colney, Norwich, United Kingdom
| | | | - Katrine L. Bøgh
- National Food Institute, Technical University of Denmark, Søborg, Denmark
| | - Louise J. Salt
- Institute of Food Research, Norwich Research Park, Colney, Norwich, United Kingdom
| | - E. N. Clare Mills
- Institute of Food Research, Norwich Research Park, Colney, Norwich, United Kingdom
| | - Charlotte B. Madsen
- National Food Institute, Technical University of Denmark, Søborg, Denmark
- * E-mail:
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Mills K, Lay J, Wu W, Robinette C, Kesic MJ, Dreskin SC, Peden DB, Hernandez M. Vitamin E, γ-tocopherol, diminishes ex vivo basophil response to dust mite allergen. Allergy 2014; 69:541-4. [PMID: 24697338 DOI: 10.1111/all.12371] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2014] [Indexed: 01/20/2023]
Abstract
Epidemiologic studies suggest that dietary vitamin E is a candidate intervention for atopic disease. We used in vitro and ex vivo exposures to test the hypothesis that the most common dietary isoform of vitamin E, γ-tocopherol (γT), could suppress FcεRI-mediated basophil activation. Rat basophilic leukemia (RBL)-SX38 cells that express human FcεRI were treated with or without γT, followed by stimulation with α-IgE. In the ex vivo study, 20 Der f 1-allergic volunteers consumed a γT-enriched supplement for 7 days. Their basophils were challenged ex vivo with α-IgE and graded doses of Der f 1 before and after the supplementation period. γt treatment of RBL-SX38 cells significantly reduced basophil degranulation and de novo TH2 cytokine production. Daily consumption of a γT-rich supplement by dust mite-allergic volunteers reduced basophil activation after ex vivo dust mite challenge. Vitamin E supplements rich in γT may be useful adjuncts in decreasing atopic disease.
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Affiliation(s)
- K. Mills
- Center for Environmental Medicine, Asthma, & Lung Biology; The University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - J. Lay
- Center for Environmental Medicine, Asthma, & Lung Biology; The University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - W. Wu
- School of Public Health; Xinxiang Medical University; Xinxiang China
| | - C. Robinette
- Center for Environmental Medicine, Asthma, & Lung Biology; The University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - M. J. Kesic
- Department of Biology; Methodist University; Fayetteville NC USA
| | - S. C. Dreskin
- Division of Allergy and Clinical Immunology; University of Colorado Health Sciences Center; Denver CO USA
| | - D. B. Peden
- Center for Environmental Medicine, Asthma, & Lung Biology; The University of North Carolina at Chapel Hill; Chapel Hill NC USA
| | - M. Hernandez
- Center for Environmental Medicine, Asthma, & Lung Biology; The University of North Carolina at Chapel Hill; Chapel Hill NC USA
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Phaseolin: A 47.5kDa protein of red kidney bean (Phaseolus vulgaris L.) plays a pivotal role in hypersensitivity induction. Int Immunopharmacol 2014; 19:178-90. [DOI: 10.1016/j.intimp.2014.01.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 01/11/2014] [Accepted: 01/13/2014] [Indexed: 12/30/2022]
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Prickett SR, Voskamp AL, Phan T, Dacumos-Hill A, Mannering SI, Rolland JM, O'Hehir RE. Ara h 1 CD4+ T cell epitope-based peptides: candidates for a peanut allergy therapeutic. Clin Exp Allergy 2014; 43:684-97. [PMID: 23711131 PMCID: PMC3709139 DOI: 10.1111/cea.12113] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 02/25/2013] [Accepted: 02/27/2013] [Indexed: 12/01/2022]
Abstract
Background Peanut allergy is a life-threatening condition; there is currently no cure. While whole allergen extracts are used for specific immunotherapy for many allergies, they can cause severe reactions and even fatalities in peanut allergy. Objective To identify short, HLA-degenerate CD4+ T cell epitope-based peptides of the major peanut allergen Ara h 1 that target allergen-specific T cells without causing IgE-mediated inflammatory cell activation, as candidates for safe peanut-specific immunotherapy. Methods Ara h 1-specific CD4+ T cell lines (TCL) were generated from peripheral blood mononuclear cells (PBMC) of peanut-allergic subjects using CFSE-based methodology. T cell epitopes were identified using CFSE and thymidine-based proliferation assays. Epitope HLA-restriction was investigated using blocking antibodies, HLA-genotyping and epitope prediction algorithms. Functional peanut-specific IgE reactivity to peptides was assessed by basophil activation assay. Results A total of 145 Ara h 1-specific TCL were generated from 18 HLA-diverse peanut-allergic subjects. The TCL recognized 20-mer peptides throughout Ara h 1. Nine 20-mers containing the most frequently recognized epitopes were selected and their recognition confirmed in 18 additional peanut-allergic subjects. Ten core epitopes were mapped within these 20-mers. These were HLA-DQ and/or HLA–DR restricted, with each presented on at least two different HLA-molecules. Seven short (≤ 20 aa) non-basophil-reactive peptides encompassing all core epitopes were designed and validated in peanut-allergic donor PBMC T cell assays. Conclusions and Clinical Relevance Short CD4+ T cell epitope-based Ara h 1 peptides were identified as novel candidates for a safe, T cell targeted peanut-specific immunotherapy for HLA-diverse populations.
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Affiliation(s)
- S R Prickett
- Department of Immunology, Monash University, Melbourne, Vic., Australia
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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. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 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] [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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Abstract
Peanut is recognized as a potent food allergen producing one of the most frequent food allergies. This fact has originated the publication of an elevated number of scientific reports dealing with peanut allergens and, especially, the prevalence of peanut allergy. For this reason, the information available on peanut allergens is increasing and the debate about peanut allergy is always renewed. This article reviews the information currently available on peanut allergens and on the techniques used for their chemical characterization. Moreover, a general overview on the current biotechnological approaches used to reduce or eliminate peanut allergens is also provided.
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Affiliation(s)
- Jorge Sáiz
- Department of Chemistry I, Faculty of Biology, Environmental Sciences, and Chemistry, University of Alcalá, 28871 Alcalá de Henares, Madrid, Spain
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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. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2832-42. [PMID: 24145103 DOI: 10.1016/j.bbapap.2013.10.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [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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Radosavljevic J, Nordlund E, Mihajlovic L, Krstic M, Bohn T, Buchert J, Velickovic TC, Smit J. Sensitizing potential of enzymatically cross-linked peanut proteins in a mouse model of peanut allergy. Mol Nutr Food Res 2013; 58:635-46. [DOI: 10.1002/mnfr.201300403] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/22/2013] [Accepted: 07/30/2013] [Indexed: 01/01/2023]
Affiliation(s)
| | | | - Luka Mihajlovic
- University of Belgrade; Faculty of Chemistry; Belgrade Serbia
| | - Maja Krstic
- University of Belgrade; Faculty of Chemistry; Belgrade Serbia
| | - Torsten Bohn
- Centre de Recherche Public - Gabriel Lippmann; Belvaux Luxembourg
| | | | | | - Joost Smit
- Institute for Risk Assessment Sciences; Utrecht University; Utrecht The Netherlands
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Pascal M, Konstantinou GN, Masilamani M, Lieberman J, Sampson HA. In silico prediction of Ara h 2 T cell epitopes in peanut-allergic children. Clin Exp Allergy 2013; 43:116-27. [PMID: 23278886 DOI: 10.1111/cea.12014] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 08/18/2012] [Accepted: 08/24/2012] [Indexed: 11/26/2022]
Abstract
BACKGROUND Despite the frequency and severity of peanut allergy, the only approved treatment is strict avoidance. Different types of immunotherapy with crude peanut extract are not universally effective and have been associated with relatively high adverse reaction rates. OBJECTIVE We sought to determine whether in silico predictive algorithms were useful in identifying candidate peptides for an Ara h 2 peptide-based vaccine using peanut-allergic patients' peripheral blood mononuclear cells (PBMCs) in vitro. A human leucocyte antigen (HLA) distribution analysis was also performed. METHODS Major histocompatibility complex (MHC)-class II-binding peptides were predicted using NetMHCIIpan-2.0 and NetMHCII-2.2 algorithms. PBMCs from 80 peanut-allergic patients were stimulated with overlapping 20-mer Ara h 2 peptides. Cell supernatant cytokine profiles were evaluated by multiplex assays. HLA-DRB1* and HLA-DQB1* typing were performed. RESULTS Four regions of overlapping sequences induced PBMC proliferation and predominant Th2 cytokine production. HLA genotyping showed 30 different DRB1* allele specificities and eight DQ serological specificities. The in silico analysis revealed similar relevant regions and predicted identical or similar core 9-mer epitopes to those identified in vitro. If relevant peptides, as determined by either in vitro or in silico analysis (15 peptides and 9 core epitopes respectively), were used in a peptide-based vaccine, they would cover virtually all subjects in the cohort studied. CONCLUSIONS AND CLINICAL RELEVANCE Four dominant regions in Ara h 2 have been identified, containing sequences that could serve as potential candidates for peptide-based immunotherapy. MHC-class II-based T cell epitope prediction algorithms for HLA-DR and -DQ loci accurately predicted Ara h 2 T cell epitopes in peanut-allergic subjects, suggesting their potential utility in a peptide-based vaccine design for food allergy.
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Affiliation(s)
- M Pascal
- Division of Allergy & Immunology and The Jaffe Food Allergy Research Institute, Mount Sinai School of Medicine, New York, NY, USA
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Kumar S, Sharma A, Verma AK, Chaudhari B, Das M, Jain S, Dwivedi PD. Allergenicity potential of red kidney bean (Phaseolus vulgaris L.) proteins in orally treated BALB/c mice and passively sensitized RBL-2H3 cells. Cell Immunol 2013; 284:37-44. [DOI: 10.1016/j.cellimm.2013.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 06/25/2013] [Accepted: 07/01/2013] [Indexed: 01/10/2023]
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IgE cross-reactivity between the major peanut allergen Ara h 2 and the nonhomologous allergens Ara h 1 and Ara h 3. J Allergy Clin Immunol 2013; 132:118-24. [DOI: 10.1016/j.jaci.2013.01.022] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 12/14/2012] [Accepted: 01/17/2013] [Indexed: 11/20/2022]
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Pellaton C, Perrin Y, Boudousquié C, Barbier N, Wassenberg J, Corradin G, Thierry AC, Audran R, Reymond C, Spertini F. Novel birch pollen specific immunotherapy formulation based on contiguous overlapping peptides. Clin Transl Allergy 2013; 3:17. [PMID: 23725004 PMCID: PMC3672070 DOI: 10.1186/2045-7022-3-17] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 05/21/2013] [Indexed: 02/08/2023] Open
Abstract
Background Synthetic contiguous overlapping peptides (COPs) may represent an alternative to allergen extracts or recombinant allergens for allergen specific immunotherapy. In combination, COPs encompass the entire allergen sequence, providing all potential T cell epitopes, while preventing IgE conformational epitopes of the native allergen. Methods Individual COPs were derived from the sequence of Bet v 1, the major allergen of birch pollen, and its known crystal structure, and designed to avoid IgE binding. Three sets of COPs were tested in vitro in competition ELISA and basophil degranulation assays. Their in vivo reactivity was determined by intraperitoneal challenge in rBet v 1 sensitized mice as well as by skin prick tests in volunteers with allergic rhinoconjunctivitis to birch pollen. Results The combination, named AllerT, of three COPs selected for undetectable IgE binding in competition assays and for the absence of basophil activation in vitro was unable to induce anaphylaxis in sensitized mice in contrast to rBet v 1. In addition no positive reactivity to AllerT was observed in skin prick tests in human volunteers allergic to birch pollen. In contrast, a second set of COPs, AllerT4-T5 displayed some residual IgE binding in competition ELISA and a weak subliminal reactivity to skin prick testing. Conclusions The hypoallergenicity of contiguous overlapping peptides was confirmed by low, if any, IgE binding activity in vitro, by the absence of basophil activation and the absence of in vivo induction of allergic reactions in mouse and human. Trial registration ClinicalTrials.gov NCT01719133
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Affiliation(s)
- Céline Pellaton
- Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon, Lausanne, 1011, Switzerland.
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Starkl P, Felix F, Krishnamurthy D, Stremnitzer C, Roth-Walter F, Prickett SR, Voskamp AL, Willensdorfer A, Szalai K, Weichselbaumer M, O'Hehir RE, Jensen-Jarolim E. An unfolded variant of the major peanut allergen Ara h 2 with decreased anaphylactic potential. Clin Exp Allergy 2013. [PMID: 23181796 DOI: 10.1111/cea.12031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Peanut allergy causes severe type 1 hypersensitivity reactions and conventional immunotherapy against peanut allergy is associated with a high risk of anaphylaxis. OBJECTIVE Our current study reports proof of concept experiments on the safety of a stably denatured variant of the major peanut allergen Ara h 2 for immunotherapy. We determined the impact of structure loss of Ara h 2 on its IgE binding and basophil degranulation capacity, T cell reactivity as well as anaphylactic potential. METHODS The secondary structure of untreated and reduced/alkylated Ara h 2 variants was determined by circular dichroism spectroscopy. We addressed human patient IgE binding to Ara h 2 by ELISA and Western blot experiments. RBL-SX38 cells were used to test the degranulation induced by untreated and reduced/alkylated Ara h 2. We assessed the anaphylactic potential of Ara h 2 variants by challenge of sensitized BALB/c mice. T cell reactivity was investigated using human Ara h 2-specific T cell lines and splenocytes isolated from sensitized mice. RESULTS Reduction/alkylation of Ara h 2 caused a decrease in IgE binding capacity, basophil degranulation and anaphylactic potential in vivo. However, the human T cell response to reduced/alkylated and untreated Ara h 2 was comparable. Mouse splenocytes showed higher metabolic activity upon stimulation with reduced/alkylated Ara h 2 and released similar IL-4, IL-13 and IFNγ levels upon treatment with either Ara h 2 variant. CONCLUSIONS AND CLINICAL RELEVANCE Reduced/alkylated Ara h 2 might be a safer alternative than native Ara h 2 for immunotherapeutic treatment of peanut allergic patients.
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Affiliation(s)
- P Starkl
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
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Abstract
Food allergy has become a major public health concern in westernized countries, and allergic reactions to peanuts are particularly common and severe. Allergens are defined as antigens that elicit an IgE response, and most allergenic materials (e.g., pollens, danders, and foods) contain multiple allergenic proteins. This has led to the concept that there are "major" allergens and allergens of less importance. "Major allergens" have been defined as allergens that bind a large amount of IgE from the majority of patients and have biologic activity. However, the ability of an allergen to cross-link complexes of IgE and its high-affinity receptor FcεRI (IgE/FcεRI), which we have termed its allergic effector activity, does not correlate well with assays of IgE binding. To identify the proteins that are the most active allergens in peanuts, we and others have employed in vitro model assays of allergen-mediated cross-linking of IgE/FcεRI complexes and have demonstrated that the most potent allergens are not necessarily those that bind the most IgE. The importance of a specific allergen can be determined by measuring the allergic effector activity of that allergen following purification under non-denaturing conditions and by specifically removing the allergen from a complex allergenic extract either by chromatography or by specific immunodepletion. In our studies of peanut allergens, our laboratory has found that two related allergens, Ara h 2 and Ara h 6, together account for the majority of the effector activity in a crude peanut extract. Furthermore, murine studies demonstrated that Ara h 2 and Ara h 6 are not only the major elicitors of anaphylaxis in this system, but also can effectively desensitize peanut-allergic mice. As a result of these observations, we propose that the definition of a major allergen should be based on the potency of that allergen in assays of allergic effector activity and demonstration that removal of that allergen from an extract results in loss of potency. Using these criteria, Ara h 2 and Ara h 6 are the major peanut allergens.
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Affiliation(s)
- Yonghua Zhuang
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado School of Medicine, 12700 E. 19th Ave., Room 10C03, Aurora, CO 80045, USA
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado School of Medicine, 12700 E. 19th Ave., Room 10C03, Aurora, CO 80045, USA
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Kim J, Lee JY, Han Y, Ahn K. Significance of Ara h 2 in clinical reactivity and effect of cooking methods on allergenicity. Ann Allergy Asthma Immunol 2012; 110:34-8. [PMID: 23244656 DOI: 10.1016/j.anai.2012.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 09/19/2012] [Accepted: 10/14/2012] [Indexed: 11/16/2022]
Abstract
BACKGROUND The prevalence and clinical severity of peanut allergy vary between Western countries and Asia. It has been suggested that cooking methods are responsible for this discrepancy. OBJECTIVES To evaluate the specific IgE responses to major peanut allergens in peanut allergic Korean children and to examine the influence of different cooking methods on peanut proteins. METHODS Raw peanut protein extracts were immunolabeled with serum samples from 42 children with a level of peanut specific IgE of 15 kUA/L or higher to detect specific binding to Ara h 1, Ara h 2, and Ara h 3. Clinical severity scores were assessed on a scale of 0 to 5. Protein extracts from boiled, roasted, fried, and pickled peanuts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with pooled serum samples from 7 patients. RESULTS Most patients' serum samples reacted with Ara h 1 (76.2%) and Ara h 3 (78.6%) from raw peanuts, whereas only 53.0% of patients had specific IgE against Ara h 2. IgE binding to Ara h 2 was more prevalent in patients with more severe reaction than in those with mild reactions. IgE binding to Ara h 2 was increased by roasting, but there was significantly less IgE binding after vinegar treatment. CONCLUSION Our results suggest that Ara h 2 is an important allergen to predict clinical symptoms but less prevalent in Korean children than in Western children. This finding may be attributed in part to different cooking methods and dietary habits among regions.
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Affiliation(s)
- Jihyun Kim
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Chen X, Wang Q, El-Mezayen R, Zhuang Y, Dreskin SC. Ara h 2 and Ara h 6 have similar allergenic activity and are substantially redundant. Int Arch Allergy Immunol 2012; 160:251-8. [PMID: 23075924 DOI: 10.1159/000341642] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 07/06/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The moderately homologous (approx. 60%) proteins Ara h 2 and Ara h 6 are the most potent peanut allergens. This study was designed to define the relative individual contributions of Ara h 2 and Ara h 6 to the overall allergenic activity of a crude peanut extract (CPE). METHODS Ara h 2 and Ara h 6 were removed from CPE by gel filtration chromatography. Ara h 2.01, Ara h 2.02 and Ara h 6 were further purified (>99%). The potency of each allergen and the ability of these allergens to reconstitute the allergenic activity of CPE depleted of Ara h 2 and Ara h 6 was measured with RBL SX-38 cells sensitized with IgE from sensitized peanut allergic patients. RESULTS The potency of the native proteins were significantly different (p < 0.0001) although not dramatically so, with a rank order of Ara h 2.01 > Ara h 2.02 > Ara h 6. The addition of either purified Ara h 2 or Ara h 6 independently at their original concentration to CPE depleted of both Ara h 2 and Ara h 6 restored 80-100% of the original CPE allergenic activity. Addition of both Ara h 2 and Ara h 6 consistently completely restored the allergenic activity of CPE. CONCLUSIONS These studies indicate that either Ara h 2 or Ara h 6 independently can account for most of the allergenic activity in a CPE and demonstrate important redundancy in the allergenic activity of these related molecules.
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Affiliation(s)
- Xueni Chen
- Division of Allergy and Clinical Immunology, Department of Medicine, University of Colorado Denver, Aurora, CO 80045, USA
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47
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Peanut component Ara h 8 sensitization and tolerance to peanut. J Allergy Clin Immunol 2012; 130:468-72. [DOI: 10.1016/j.jaci.2012.05.019] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/16/2012] [Accepted: 05/17/2012] [Indexed: 11/21/2022]
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Sverremark-Ekström E, Hultgren EH, Borres MP, Nilsson C. Peanut sensitization during the first 5 yr of life is associated with elevated levels of peanut-specific IgG. Pediatr Allergy Immunol 2012; 23:224-9. [PMID: 22509759 DOI: 10.1111/j.1399-3038.2012.01290.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Allergen-specific IgE antibodies are implicated in allergic diseases while allergen-specific IgG antibodies have been proposed to prevent allergic reactions. The objective for this study was to study whether the immune response (IgG and IgG4) to peanut differs in IgE-sensitized and non-sensitized young children. METHODS A total of 239 children have been followed prospectively from birth to 5 yr of age. The levels of IgG and IgG4 to peanut, Ara h 2, and Ara h 8 were analyzed at 2 and 5 yr of age and related to IgE sensitization and peanut consumption. RESULTS The levels of peanut-specific IgG and IgG4 were significantly higher in peanut-sensitized children at 2 and 5 yr of age when compared with non-sensitized children and children sensitized to other food/inhalant allergens. A strong correlation was seen between levels of peanut-specific IgG/IgG4-ratios and peanut-specific IgE at 5 yr of age. Children avoiding peanuts, a subgroup of the peanut sensitized, had statistically significant higher levels of IgE to peanut and a tendency of higher IgG and IgG4 levels to peanut. In the avoidance group, significant correlations between IgE and IgG/IgG4 to peanut were found compared with children eating peanuts. CONCLUSION Peanut-specific IgG or IgG4 levels were elevated in peanut-sensitized children especially those avoiding peanuts. In our study, IgG and IgG4 do not seem to indicate tolerance or protection from sensitization.
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Affiliation(s)
- E Sverremark-Ekström
- Department of Immunology, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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Hazebrouck S, Guillon B, Drumare MF, Paty E, Wal JM, Bernard H. Trypsin resistance of the major peanut allergen Ara h 6 and allergenicity of the digestion products are abolished after selective disruption of disulfide bonds. Mol Nutr Food Res 2012; 56:548-57. [DOI: 10.1002/mnfr.201100614] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Stéphane Hazebrouck
- INRA, UR 496, Unité d’Immuno-Allergie Alimentaire, CEA/iBiTeC-S/SPI, CEA de Saclay; Gif-sur-Yvette France
| | - Blanche Guillon
- INRA, UR 496, Unité d’Immuno-Allergie Alimentaire, CEA/iBiTeC-S/SPI, CEA de Saclay; Gif-sur-Yvette France
| | - Marie-Françoise Drumare
- INRA, UR 496, Unité d’Immuno-Allergie Alimentaire, CEA/iBiTeC-S/SPI, CEA de Saclay; Gif-sur-Yvette France
| | - Evelyne Paty
- Université Paris Descartes Assistance Publique des Hôpitaux de Paris; Hôpital Necker Enfants Malades; Paris France
| | - Jean-Michel Wal
- INRA, UR 496, Unité d’Immuno-Allergie Alimentaire, CEA/iBiTeC-S/SPI, CEA de Saclay; Gif-sur-Yvette France
| | - Hervé Bernard
- INRA, UR 496, Unité d’Immuno-Allergie Alimentaire, CEA/iBiTeC-S/SPI, CEA de Saclay; Gif-sur-Yvette France
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Vissers YM, Wichers HJ, Savelkoul HFJ. Influence of Food Processing, Digestion and the Food Matrix on Allergenicity & Cellular Measures of Allergenicity. MULTIDISCIPLINARY APPROACHES TO ALLERGIES 2012. [DOI: 10.1007/978-3-642-31609-8_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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