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Background: Food allergies affect 4-8% of children and are constantly on the rise, thus making allergies a timely issue. Most importantly, prevention strategies are nonexistent, and current therapeutic strategies have limited efficacy and need to be improved. One alternative to prevent or reduce allergies, particularly during infancy, could consist of modulating maternal immunity and microbiota using nondigestible food ingredients, such as prebiotics. For this purpose, we studied the preventive effects of prebiotics in Balb/c mothers during pregnancy and breastfeeding on food allergy development in offspring mice. Methods: After weaning, the offspring from mothers that were exposed to GOS/inulin mixture or fed a control diet were intraperitoneally sensitized to wheat proteins to induce a systemic allergic response and orally exposed to the same allergen. Immunological, physiological, and microbial parameters were analyzed. Results: GOS/inulin mixture diet modified the microbiota of mothers and their offspring. Offspring from mothers that received GOS/inulin prebiotics were protected against food allergies and displayed lower clinical scores, specifically of IgE and histamine levels, compared to offspring from mothers fed a control diet. Moreover, GOS/inulin supplementation for the mother resulted in stronger intestinal permeability in the offspring. Enhancement of the regulatory response to allergic inflammation and changes in the Th2/Th1 balance toward a dampened Th2 response were observed in mice from GOS/inulin mixture-exposed mothers. Conclusion: The treatment of pregnant and lactating mice with nondigestible GOS/inulin prebiotics promotes a long-term protective effect against food allergies in the offspring. [ABSTRACT FROM AUTHOR]

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 allergen profiles for these patients in comparison with those of patients allergic to wheat and to identify Ig E-binding epitopes. Methods Sera were obtained from 15 patients allergic to DG and from nine patients allergic to wheat proteins ( WP). Ig E-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. Results Compared to the heterogeneous pattern of allergens detected by Ig E from patients allergic to WP, responses of patients allergic to DG were homogeneous. In ELISA, all the sera displayed Ig E 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. Conclusion Allergy to DG is a separate entity from wheat allergy. It can be evidenced by strong Ig E binding to deamidated gliadins or peptides of the type QPEEPFPE. [ABSTRACT FROM AUTHOR]

Summary Background At present, B cell epitopes involved in food allergy to wheat are known only for a few allergens and a few categories of patients. Objective To characterize the epitopes of different wheat kernel allergens: α-, γ, ω2, and ω5-gliadin, a low-molecular-weight (LMW) glutenin subunit, and a lipid transfer protein (LTP1) recognized by allergic patients and by sensitized mice and provide further understanding of the role of structure in determining allergic response. Methods Sera were obtained from 39 patients suffering from food allergy to wheat. BALB/c mice were sensitized to gliadins or LTP1 by intraperitoneal immunizations. Continuous epitopes bound by IgE were delineated by the Pepscan technique. The response to reduced, alkylated LTP1 was compared with that of the native form to evaluate the importance of protein folding on IgE reactivity. Results Few continuous epitopes of LTP1 reacted with IgE from allergic patients and mice, but one of them was common to several patients and sensitized mice. The unfolded protein was not recognized by either patient or mouse IgE, emphasizing the major role of LTP1 folding and discontinuous epitopes in IgE-binding. In contrast, many continuous epitopes were detected by patient and mouse IgE especially for an ω5-gliadin, which is an unstructured protein, and to a lesser extent, for the other gliadins and a LMW-glutenin subunit. Conclusion and Clinical Relevance The conformation of LTP1 appeared to have a strong impact on the type of IgE-binding epitopes elicited by this protein in both man and mouse. The responses in mice sensitized to gliadins or LTP1 were sufficiently comparable with the human response in terms of IgE-binding epitopes to provide support for the use of the mouse model in further investigations. Cite this as: S. Denery-Papini, M. Bodinier, F. Pineau, S. Triballeau, O. Tranquet, K. Adel-Patient, D.A. Moneret-Vautrin, B. Bakan, D. Marion, T. Mothes, H. Mameri and D. Kasarda, Clinical & Experimental Allergy, 2011 (41) 1478-1492. [ABSTRACT FROM AUTHOR]

Food allergy to wheat induces different symptoms as atopic eczema/dermatitis syndrome (AEDS), urticaria and more severe reactions as wheat-dependent exercise-induced anaphylaxis (WDEIA). Different gliadin classes are involved in this allergy but IgE-binding epitopes are known only onω5-gliadins and for WDEIA cases.The aim of the study was to identify IgE-binding epitopes on several gliadin classes and for several patients with different symptoms and ages.Eleven sera were analysed by pepscan with overlapping synthetic peptides.Sera from five patients with anaphylaxis, urticaria or WDEIA, displayed strong IgE-binding to sequential epitopes of the repetitive domains ofα β,γ,ω2 orω5-gliadins with two immunodominant epitopes onω5-gliadin and a consensus motif of the type QQX1PX2QQ (X1 being L, F, S or I and X2 Q, E or G). One patient allergic to deamidated wheat proteins also had IgE to a repetitive peptide ofγ andω2-gliadins of the type QPQQPFP. Sera from four patients with AEDS detected no linear epitopes on gliadins, despite the fact that they contained specific IgE toα,β,γ orω-gliadins. One child with AEDS recognized cysteine-containing sequences in the nonrepetitive domains ofα β andγ-gliadins.B epitopes in wheat allergy were different from B epitopes of coeliac disease. Differences exist in IgE-binding epitopes between patients with food allergy to wheat. IgE from those suffering from WDEIA, anaphylaxis and urticaria detected sequential epitopes in the repetitive domain of gliadins whereas IgE from AEDS patients probably recognized conformational epitopes. [ABSTRACT FROM AUTHOR]

Examines the role of major histocompatibility cell (MHC)-peptide multimers as tools of choice for detecting and sorting antigen-specific T-cells. Generation of MHC tetramers; Detection of antigen-specific T cells with tetramers; sorting specific T cells with MHC multimers.

The article discusses a study on the effectiveness of gestational supplementation with 2'-Fucosyllactose (2'-FL) in preventing food allergies in offspring. The study found that maternal diet during pregnancy and breastfeeding can impact the immune system, gut microbiota, and epithelial barriers, leading to allergies. The research showed that gestational supplementation with 2'-FL protected offspring from food allergies by creating a specific microbial and immune imprint. This study highlights the potential benefits of maternal nutrition and supplementation in preventing allergies in children, suggesting further research in high-risk populations. [Extracted from the article]

As for IgM, human IgA occurs either as soluble molecules in plasma and various other body fluids, or as membrane-bound molecules on differentiated B cells, where they are part of the B-cell receptor for antigen (BCR). We studied the structure of transcripts encoding the membrane- anchored α-chain of the human BCRα, which may be present in two different forms resulting from alternate splicing of the α-chain mRNA (type I or type II). The ratio of type I versus type II did not vary upon stimulation of a B-cell line with various cytokines. Rather, it differed strikingly in cells expressing either the IgAl or IgA2 isotype of the BCRα with virtually no type II α-chain in the latter. Co-modulation experiments also yielded different results for both isotypes, since they demonstrated a physical association of both membrane (m)IgA1 and mIgA2 with CD79b, the β component of the BCR Igα/Igβ heterodimer, but only of mIgAl with CD19. Whatever the isotype, the BCR of the IgA class was able to carry out signal transduction upon cross-linking by specific monoclonal antibodies but, in contrast to mIgM, it relied mainly on the entry of extracellular Ca2+ rather than on the release of intracellular stocks. [ABSTRACT FROM AUTHOR]

Significant efforts are necessary to introduce new dietary protein sources to feed a growing world population while maintaining food supply chain sustainability. Such a sustainable protein transition includes the use of highly modified proteins from side streams or the introduction of new protein sources that may lead to increased clinically relevant allergic sensitization. With food allergy being a major health problem of increasing concern, understanding the potential allergenicity of new or modified proteins is crucial to ensure public health protection. The best predictive risk assessment methods currently relied on are in vivo models, making the choice of endpoint parameters a key element in evaluating the sensitizing capacity of novel proteins. Here, we provide a comprehensive overview of the most frequently used in vivo and ex vivo endpoints in murine food allergy models, addressing their strengths and limitations for assessing sensitization risks. For optimal laboratory-to-laboratory reproducibility and reliable use of predictive tests for protein risk assessment, it is important that researchers maintain and apply the same relevant parameters and procedures. Thus, there is an urgent need for a consensus on key food allergy parameters to be applied in future food allergy research in synergy between both knowledge institutes and clinicians., (© 2019 The Authors. Allergy Published by John Wiley & Sons Ltd.)