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Wheat proteins are involved in respiratory allergy, contact allergy and food allergy. Wheat allergens involve in these pathologies are well-known. However, establishment of wheat allergy diagnostic can be sometimes difficult on account of the complex allergenic composition of skin prick test (SPT) solutions of wheat flour. Therefore, we have studie...
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Background:
Various clinical patterns based on routes of sensitization and sensitized allergens are reported in adult-onset IgE-mediated wheat allergy. There is still a paucity of data on IgE-bound wheat allergen profiles in wheat challenge-proven adult-onset wheat allergic cases. Therefore, we aim to identify the major sensitized allergens in Tha...
Theterm gluten intolerance may refer to three types of human disorders: autoimmune celiac disease (CD), allergy to wheat and non-celiac gluten sensitivity (NCGS). Gluten is a mixture of prolamin proteins present mostly in wheat, but also in barley, rye and oat. Gluten can be subdivided into three major groups: S-rich, S-poor and high molecular weig...
Recently an increasing number of patients with wheat-dependent exercise-induced anaphylaxis (WDEIA), developed during or after using hydrolyzed wheat protein (HWP)-containing soap (HWP-WDEIA), were reported in Japan.
To clarify the relation between WDEIA and HWP-containing soap and their prognosis, we investigated the patients who visited Hiroshima...
Since the correct labeling of foods is the only effective way of protecting celiac disease patients and people allergic to gluten, it is essential to have reliable methods to detect the presence of gluten-containing cereals in foods. DNA-based methods have their merits as complementary approaches to immunochemical assays to detect the possible glut...
Background
In wheat-dependent exercise-induced anaphylaxis (WDEIA), cofactors such as exercise, acetylsalicylic acid (ASA), alcohol or unfavorable climatic conditions are required to elicit a reaction to wheat products. The mechanism of action of these cofactors is unknown, but an increase of gliadin absorption has been speculated. Our objectives w...
Citations
... GemTec HWP (Manildra Group, Australia) incorporated into deli meats was responsible for the allergic reaction; sold under the name 'wheat isolate', it was characterised as a deamidated gluten. As a result of this allergic event, an extract corresponding to a deamidated gluten was proposed for the cutaneous diagnosis in 2006 (Battais et al. 2006). Between 2002 and 2014, the Allergy Vigilance Network (http://www.allergyvigilance.org/) ...
... In fact, the native wheat extracts proposed for skin tests and for specific IgE assays are ineffective for the diagnosis and laboratory exploration of these patients allergic to deamidated gluten. The characterisation of modified gluten, involved in the first French case described by Leduc et al., carried out in our group, resulted in the proposal in 2006 of a deamidated gluten extract for the diagnosis of patients allergic to deamidated gluten (Battais et al. 2006). For the same purpose, Nakamura et al. proposed in 2014 to use Glupearl 19S for Japanese patients (Nakamura et al. 2014). ...
Wheat gluten can be chemically or enzymatically hydrolysed to produce functional ingredients useful in food and cosmetics. However severe allergies to hydrolysed wheat proteins (HWP) have been described in Europe and Japan since the early 2000's. Triggering proteins and IgE epitopes were described both for French and Japanese cohorts and appeared remarkably similar leading to define a new wheat allergic entity. Deamidation induced by functionalisation generate neo-allergens responsible for this particular allergy. This article aims to review the processes leading to deamidation and the clinical features of the patients suffering from this allergy. Then the molecular determinants involved in HWP-allergy were exhaustively described and hypothesis regarding the sensitizing mechanism of HWP-allergy are discussed. Finally, current regulation and tools aiming at managing this risk associated with HWP are presented.
... A fatal consequence of food allergy may be the occurrence of life-threatening anaphylactic reaction. In the case of allergy to wheat, the main allergens include α-amylase / trypsin inhibitors and ω-5 gliadin, which is an element of gluten [37]. ...
Gluten, which is a protein found in wheat, can trigger some gastrointestinal diseases in people with genetic predisposition. Gluten related disorders include celiac disease (CD), wheat allergy, baker's asthma and non-celiac gluten sensivity (NCGS). Approximately 1% of population suffers from celiac disease. It is believed, that the occurrence of the disease is determined by the interaction of genetic, immunological and environmental factors. The consequence of the inflammatory process is the atrophy of the intestinal villi. That results in impaired bowel motility, improper digestion and impaired absorption of substances contained in the diet. Wheat allergy occurs among people with a genetic predisposition to allergies. People with this disorder are sensitized to products containing gluten and every contact with this antigen leads to mast cell activation and the release of mediators of the allergic reaction-mainly histamine. They mainly affect the skin (urticaria, atopic eczema, angioedema), digestive system (nausea, vomiting, spasmic abdominal pain) and respiratory tract (asthma, allergic rhinitis). Baker's asthma is an interesting and common allergic, occupational disorder related to inhalation of flour containing gluten. The main symptoms include: conjunctivitis, rhinitis, dermatitis, as well as work-related cough and dyspnea. First reports on non-celiac gluten sensitivity (NCGS) appeared in 1980. The diagnosis of non-celiac gluten sensitivity is based on the exclusion of celiac disease and food allergy in a patient who has symptoms induced by ingestion of gluten. The exact pathomechanism of this disease is still unknown. Interestingly, some researches doubt that this World Scient ific News 100 (2018) 154-164-155-disorder is caused by gluten intake. All of the above-mentioned diseases have a similar spectrum of clinical symptoms, and as part of the treatment require an elimination diet with the exclusion of gluten. The aim of this study is to provide information on gluten-related diseases, taking into account their pathomechanism and clinical picture.
... Wheat proteins, of which at least 80% are gluten proteins, have been shown to trigger IgEmediated food, respiratory and contact allergies [1,2]. The group containing gluten proteins is composed of approximately 100 proteins, which can be classified into 2 groups: monomeric proteins (the gliadins) and polymeric proteins (the glutenin subunits). ...
Background
Acid-hydrolyzed wheat proteins (acid-HWPs) have been shown to provoke severe allergic reactions in Europe and Japan that are distinct from classical wheat allergies. Acid-HWPs were shown to contain neo-epitopes induced by the deamidation of gluten proteins. However, products with variable rates of deamidation can be found.
Objectives
In this work, we studied the effect of the extent of wheat proteins deamidation on its allergenicity. A recombinant chimeric IgE was produced and compared to patients’ IgE for its capacity to assess the IgE-mediated triggering potential of acid-HWPs.
Methods
Sera from acid-HWP allergic patients were analyzed via ELISA and a functional basophil assay for their IgE reactivity to wheat proteins with different deamidation levels. A chimeric mouse/human IgE (chIgE-DG1) specific for the main neo-epitope, QPEEPFPE, involved in allergy to acid-HWPs was characterized with respect to its functionality and its reactivity compared to that of patients’ IgE.
Results
Acid-HWPs with medium (30%) and high (50–60%) deamidation levels displayed a markedly stronger IgE binding and capacity to activate basophils than those of samples with weak (15%) deamidation levels. The monoclonal chIgE-DG1 allowed basophil degranulation in the presence of deamidated wheat proteins. ChIgE-DG1 was found to mimic patients’ IgE reactivity and displayed the same ability to rank acid-HWP products in a degranulation assay.
Conclusion
Increasing the deamidation level of products from 15% to 60% resulted in an approximately 2-fold increase in their antigenicity and a 100-fold increase in their eliciting potential. The chimeric ChIgE-DG1 may be a useful tool to evaluate functionalized glutens for their allergenic potential. By mimicking patient sera reactivity, chIgE-DG1 also provided data on the patients' IgE repertoire and on the functionality of certain repeated epitopes in gluten proteins.
... Ingestion (food allergy and celiac desease), inhalation (respiratory allergy), and skin contact exposure (contact allergy) are three ways for exposure to occur and resultant sensitization to be caused by wheat grain proteins. 55 The mechanism of immunological reaction (intolerance, hypersensitivity reaction) depends on the type of allergen and how it is exposed to the immune system (Figure 3). For example, the inhalation of amylase/trypsin inhibitors might be associated with the clinically termed "Baker's asthma" 27,28 and oral exposure would likely be associated with food allergy 56,57 or WDEIA. ...
The amount of clinically relevant, allergy-related proteins in wheat grain is still largely unknown. The application of proteomics may create a platform not only for identification and characterization, but also for quantitation of these proteins. The aim of this study was to evaluate the data-independent quantitative mass spectrometry (MS(E)) approach in combination with 76 wheat allergenic sequences downloaded from the AllergenOnline database ( www.allergenonline.org ) as a starting point. Alcohol soluble extracts of gliadin and glutenin proteins were analyzed. This approach has resulted in identification and quantification of 15 allergenic protein isoforms that belong to amylase/trypsin inhibitors, γ-gliadins, and high or low molecular weight glutenins. Additionally, several peptides carrying four previously discovered epitopes of γ-gliadin B precursor have been detected. These data were validated against the UniProt database, which contained 11764 Triticeae protein sequences. The identified allergens are discussed in relation to Baker's asthma, food allergy, wheat dependent exercise induced anaphylaxis, atopic dermatitis, and celiac disease (i.e., gluten-sensitive enteropathy). In summary, the results showed that the MS(E) approach is suitable for quantitative analysis and allergens profiling in wheat varieties and/or other food matrices.
... Since then, 14 cases of severe allergic reactions to deamidated gluten (DG) in patients tolerant to wheat have been reported in France through the Allergy Vigilance Network (www.allergyvigilance.org). A solution of wheat isolate for skin prick test was proposed in order to help the diagnosis of allergy to DG (6). However, a differential diagnosis between a specific allergy to DG and an allergy to native WP is not always easy, as the isolate fraction contains not only modified wheat allergens but also some native allergens involved in WP allergy. ...
Gluten proteins can be modified by deamidation to enhance their solubility and technological applications. However, severe allergic reactions have been reported after the consumption of food products containing deamidated gluten (DG) in subjects tolerant to wheat. This work aimed to characterize allergen profiles for these patients in comparison with those of patients allergic to wheat and to identify IgE-binding epitopes.
Sera were obtained from 15 patients allergic to DG and from nine patients allergic to wheat proteins (WP). IgE-binding profiles were characterized both in ELISA and in a humanized rat basophilic leukaemia (RBL) cell model. Epitopes were mapped on γ- and ω2-gliadin sequences by Pepscan, and effect of glutamine/glutamic acid substitutions was studied.
Compared to the heterogeneous pattern of allergens detected by IgE from patients allergic to WP, responses of patients allergic to DG were homogeneous. In ELISA, all the sera displayed IgE binding to deamidated γ- and ω2-gliadins and deamidated total gliadins, frequently with high concentrations. These modified proteins induced RBL degranulation with most of the sera from DG-allergic patients. A consensus epitope was found on native γ- and ω2-gliadins (QPQQPFPQ); it was repeated several times in their sequences. The substitution of two or three glutamines of this epitope into glutamic acid at positions Q3 or Q4 and Q8 (QPEEPFPE) increased its recognition the best.
Allergy to DG is a separate entity from wheat allergy. It can be evidenced by strong IgE binding to deamidated gliadins or peptides of the type QPEEPFPE.
Cette thèse actualise les connaissances de l'évaluation de l'allergénicité des aliments et son application au diagnostic de l'allergie alimentaire. Après la définition, les caractéristiques et la classification des allergènes alimentaires, les phénomènes physico-chimiques modifiant l'allergénicité des aliments ainsi que les réactivités croisées sont décrites. Ainsi sont introduits les outils cliniques et biologiques utiles au diagnostic de l'allergie alimentaire et à la détection des traces d'allergènes alimentaires. Une collaboration étroite entre cliniciens et chercheurs biologistes, permet d'optimiser la prise en charge diagnostique et thérapeutique de l'allergie alimentaire. Cette démarche se concrétise par la mise à disposition et l'utilisation de divers outils (développement d'allergènes recombinants, dosage de contaminants alimentaires dans des médicaments ou aliments, ...) et est illustrée par diverses mises en situation clinique réelles.
To investigate the effects of food matrices and extraction procedures for different test kits used for determination of gluten, six commercially available test kits were evaluated: R- Biopharm RIDASCREEN® Gliadin, RIDASCREEN® FAST Gliadin, RIDAQUICK Gliadin, Neogen Veratox® for Gliadin, Tepnel BioKits Gluten Assay kit, and Morinaga Wheat Protein ELISA kit. The food matrices used were gluten-free guar gum and high-fiber bread mix, also spiked with different concentrations of gluten standard reference material (SRM 8418) obtained from National Institute of Standards and Technologies (NIST). In addition, 30 gluten-free samples were surveyed for gluten content. A homogeneity study showed that spiked gluten reference materials were evenly distributed in food matrices. Because sample extraction mixtures used by the kits are different, extraction efficiencies were carefully evaluated, especially for Neogen and R-Biopharm kits, which provide the same two options for sample extraction, aqueous alcohol and cocktail buffer. Results obtained with the six assay systems and extraction procedures differed considerably. Extraction with cocktail gave almost two times higher concentration of gluten than that from ethanol extraction using RIDASCREEN kits. Further investigation of the kits resulted in divergent findings. Depending on test methods or extraction procedures used, false positives and negatives were observed. This variation creates uncertainty to end users. There is an urgent need for harmonization of the use of reference materials in control standards, and validation of extraction procedures in order to define the analytical results.
Background: Gluten proteins can be modified by deamidation to enhance their solubility and technological applications. However, severe allergic reactions have been reported after the consumption of food products containing deamidated gluten (DG) in subjects tolerant to wheat. This work aimed to characterize aller-gen profiles for these patients in comparison with those of patients allergic to wheat and to identify IgE-binding epitopes. Methods: Sera were obtained from 15 patients allergic to DG and from nine patients allergic to wheat proteins (WP). IgE-binding profiles were characterized both in ELISA and in a humanized rat basophilic leukaemia (RBL) cell model. Epitopes were mapped on c-and x2-gliadin sequences by Pepscan, and effect of glutamine/glutamic acid substitutions was studied. Results: Compared to the heterogeneous pattern of allergens detected by IgE from patients allergic to WP, responses of patients allergic to DG were homogeneous. In ELISA, all the sera displayed IgE binding to deamidated c-and x2-gliadins and deamidated total gliadins, frequently with high concentrations. These modified proteins induced RBL degranulation with most of the sera from DG-allergic patients. A consensus epitope was found on native c-and x2-gliadins (QPQQPFPQ); it was repeated several times in their sequences. The substitution of two or three glutamines of this epitope into glutamic acid at positions Q3 or Q4 and Q8 (QPEEPFPE) increased its recognition the best. Conclusion: Allergy to DG is a separate entity from wheat allergy. It can be evidenced by strong IgE binding to deamidated gliadins or peptides of the type QPEEPFPE.
Precise measures of gliadin (Glia) and glutenin (Glu) proteins in wheat grain are largely unknown despite their association with celiac disease, various allergies, and physical processing properties of wheat. Developing methods to quantitatively measure clinically relevant proteins could support advancements in understanding exposure thresholds and clinical study design. The aim of this study was to use a data-independent mass spectrometry (MS(E)) approach for quantifying gliadin and glutenin proteins in wheat grain. The biological replicated analysis yielded concentrations for 34 gliadin and 22 glutenin proteins. The primary focus of this survey was on measuring celiac disease proteins and Baker´s asthma associated proteins along with the proteins associated with viscoelastic properties of wheat flour and grain texture. The technical coefficients of variation ranged from 0.12 to 1.39 and indicate that MS(E) proteomics is a reproducible quantitative method for the determination of gliadin and glutenin content in the highly complex matrix of protein extracts from wheat grain.
