Food allergy

IgE-Mediated Activation of Mast Cells and Basophils in Health and Disease

Type 2-mediated immune responses protect the body against environmental threats at barrier surfaces, such as large parasites and environmental toxins, and facilitate the repair of inflammatory tissue damage. However, maladaptive responses to typically nonpathogenic substances, commonly known as allergens, can lead to the development of allergic diseases. Type 2 immunity involves a series of prototype TH2 cytokines (IL-4, IL-5, IL-13) and alarmins (IL-33, TSLP) that promote the generation of adaptive CD4+ helper Type 2 cells and humoral products such as allergen-specific IgE. Mast cells and basophils are integral players in this network, serving as primary effectors of IgE-mediated responses. These cells bind IgE via high-affinity IgE receptors (FcεRI) expressed on their surface and, upon activation by allergens, release a variety of mediators that regulate tissue responses, attract and modulate other inflammatory cells, and contribute to tissue repair. Here, we review the biology and effector mechanisms of these cells, focusing primarily on their role in mediating IgE responses in both physiological and pathological contexts.

Prevalence and Impact of Food Allergies Among Jordanian Schoolchildren: A Comprehensive Analysis of Parent-Reported Data and Associated Atopic Conditions

Background: Food allergies, characterized by immune reactions to food proteins, have emerged as an increasing global concern, impacting over 10% of the population. This study investigates the prevalence of food allergies among schoolchildren aged 5-14 years in northern and central Jordan. Methods: A randomized cross-sectional online questionnaire was administered to students aged 5-14 years residing in the central and northern regions of Jordan. Parents of these students (n = 1629) completed the questionnaire, which comprised information on demographics, dietary habits, food allergies, and allergy history. Results: The parent-reported food allergies exhibited a prevalence of 11.5% (95% confidence interval = 10-13%). Of these reported allergies, 10.1% (95% CI = 8.6-11.7%) were classified as convincing, while only 5.7% (95% CI = 4.5-6.8%) received a formal diagnosis from a healthcare professional. The most commonly reported allergens included eggs (17.8%), cow's milk (15.8%), peanuts (14.5%), and strawberries (13.8%). The majority of children (67.1%) had a single reported allergen, while 15.8% had two, and 17.2% had more than two allergens identified. Food allergies were significantly more prevalent among children with comorbid atopic conditions and those with a family history of allergies. Additionally, regional variations were observed, with high prevalence rates in metropolitan regions. Conclusion: This study emphasizes the significance of considering persuasive food allergy (FA) data in addition to parent-reported information. The findings highlight the considerable burden of food allergies and their relationship with other atopic disorders. Comprehensive management strategies and further research to elucidate the underlying causes of food allergies are necessary.

Tolerogenic nanovaccines for the treatment of type I allergic diseases

The high prevalence of type I allergic diseases such as allergic rhinitis, allergic asthma, food allergies, allergic conjunctivitis, and atopic dermatitis has emerged as a significant public health concern globally. Failure of immune tolerance to ordinarily harmless substances or stimulation, and subsequent induction of T helper 2 cells by antigen-presenting cells evokes the allergic immune response, which results in persistent inflammation, tissue damage, and organ function impairment. Current therapeutic approaches for allergic diseases include avoiding allergen exposure, corticosteroids, biologics, etc. However, these strategies only relieve allergic symptoms but hardly prevent the deteriorative progression and may have adverse effects on patients. With the rapid development of nanotechnology and immunology, emerging tolerogenic nanovaccines represent novel approaches with the potential to cure type I allergic diseases rather than merely alleviate symptoms. In this review, we expound the burgeoning field of tolerogenic nanovaccines against type I allergic diseases, highlight various types of antigens employed in constructing allergen extracts, protein/peptide and nucleic acid-based tolerogenic nanovaccines, and discuss their application in allergic rhinitis, allergic asthma, food allergies, allergic conjunctivitis, and atopic dermatitis.

Age-dependence of food allergy due to decreased supply of naïve T cells

Food allergies to eggs and cow's milk are common during infancy but often undergo desensitization during childhood. To investigate the age dependence of food allergies, we develop a simple mathematical model focusing on T helper 2 cells (Th2) causing allergies and induced regulatory T cells (iTreg) suppressing them. We assume as follows: Both types of cells differentiate from naïve T cells reactive to specific food allergens, with the rate of supply from the thymus decreasing with age. Naïve T cells are activated by allergens in peripheral tissues, differentiating into both Th2 and iTreg cells. The activation rate of Th2 cells is reduced by iTreg cells. Th2 cells promote allergies while iTreg cells help mitigate them. Analyses show that food allergies may develop at one age and resolve at a later age. Negative selection in the thymus reduces the number of naïve T cells that react to proteins resembling components of the body. As a result, allergies to these substances tend to start and resolve earlier in life than those to dissimilar materials. Food allergy starting at an older age tends to have a longer duration if the rate of naïve T cell supply decreases according to a hyperbolic (instead of exponential) function of age.

The Impact of Dietary Counseling on the Nutritional Status of Pediatric Patients with Non-IgE-Mediated Gastrointestinal Food Allergies: A Non-Randomized, Prospective Intervention Study

Background/Objectives: Pediatric patients with non-IgE-mediated gastrointestinal food allergies (non-IgE-GIFAs) may experience alterations of nutritional status. This non-randomized, prospective intervention study investigated the impact of dietary counseling on nutritional status in pediatric patients with non-IgE-GIFAs. Methods: Patients of both sexes aged 0-14 years newly diagnosed with non-IgE-GIFAs received dietary counseling provided by certified pediatric dietitians immediately after diagnosis. Nutritional status parameters were assessed to identify nutritional status alterations at baseline and after 12 months of intervention (T12). Results: The study included 100 patients (58% male, mean age 8.5 ± 8.8 months). Non-IgE-GIFAs phenotypes included food protein-induced enteropathy (FPE, 44%), food protein-induced enterocolitis syndrome (FPIES, 11%), food protein-induced allergic proctocolitis (FPIAP, 17%), and food protein-induced motility disorders (FPIMD, 28%). At diagnosis, 1% was affected by obesity (1 FPIAP), 5% were affected by overweight (2 FPE, 1 FPIAP, and 2 FPIMD), 7% were moderately underweight (5 FPE and 2 FPIMD), 1% was severely underweight (1 FPE), 7% were moderately stunted (4 FPE, 1 FPIAP, and 2 FPIMD), 16% were moderately wasted (11 FPE, 1 FPIES, 1 FPIAP, and 3 FPIMD), and 4% were severely wasted (2 FPE and 2 FPIMD). At T12, improvements in anthropometric parameters were observed, along with a reduction in the prevalence of malnutrition by excess (6% at diagnosis vs. 2% at T12) and a reduction in the undernutrition subtypes rate, including underweight, stunting, and wasting (26% at diagnosis vs. 3% at T12, p < 0.001). Conclusions: Non-IgE-GIFAs can negatively impact the nutritional status of pediatric patients. Thus, dietary counseling could be an effective strategy for preventing and managing nutritional alterations in these patients.

The transcription factor Nrf2 links Th2-mediated experimental allergy to food preservatives

Introduction

Immune-mediated adverse reactions to food allergens are rising at a striking rate, for reasons that are not completely understood. Our previous studies suggest that the stress-activated transcription factor Nrf2 (Nuclear factor erythroid 2 -related factor) promotes Th2 differentiation, while inhibiting Th1 differentiation.

Methods

In the present studies, we investigated the effect of Nrf2 activation on sensitization and anaphylaxis in response to food allergen in BALB/c mice. Specifically, we determined the effect of the Nrf2 activator and common food preservative tBHQ (tert-butylhydroquinone) on immune response to food allergen in Balb/c mice and SCID mice that received either wild-type or Nrf2-deficient CD4 T cells.

Results

Our results demonstrate that tBHQ strongly increases IgE sensitization to ovalbumin (OVA) with a concurrent increase in plasma IgG1 concentrations. In addition, tBHQ in diet also exacerbated anaphylaxis and increased mast cell degranulation. In a recall response, tBHQ promoted a type 2 T cell response. Notably, adoptive transfer studies in SCID recipient mice indicate that Nrf2 expression in CD4+ T cells is critical to sensitization and anaphylaxis in response to food allergen. Likewise, the effects of tBHQ on sensitization and challenge are dependent on Nrf2 expression in CD4+ T cells.

Conclusion

Overall, these studies point to a key role for Nrf2 in the immune response to food allergen. In addition, this study shows that the common food preservative tBHQ promotes allergic sensitization and anaphylaxis in experimental food allergy.

Quantitative food allergen risk assessment: Evolving concepts, modern approaches, and industry implications

Food safety is crucially linked to the food system, ensuring safe production, handling, and distribution to protect public health. Food allergy has been considered as a public health and food safety issue. Despite being widely regarded as a prevailing strategy for managing food allergies, strict food avoidance faces challenges due to allergen cross-contact in the food supply chain and the potential for inaccurate allergen labeling. Hence, a scientific approach to assess allergen risk in this context is imperative. In this review, a novel approach to managing food allergies, referred to as quantitative food allergen risk assessment, is presented. This discussion covered the evolving concepts and modern analytical approaches. Moreover, this review delves into the current application of quantitative food allergen risk assessment. Finally, a valuable tool for food allergen risk assessment in the food industry, Voluntary Incidental Trace Allergen Labelling (VITAL), was introduced. The establishment of a globally harmonized and standardized quantitative food allergen risk assessment framework could facilitate the promotion of international harmonization of allergen labeling, support food allergic consumers in making safe food choices, and safeguard the health of allergic individuals across various regions and ethnicities. The implementation of food allergen risk assessment could ensure both food supply chain safety and guide the establishment of acceptable allergen cross-contact levels, enhancing food safety and bolstering the integrity and sustainability of the food system.

Differential T follicular helper cell phenotypes distinguish IgE-mediated milk allergy from eosinophilic esophagitis in children

BACKGROUND

IgE-mediated food allergy and eosinophilic esophagitis (EoE) are diseases commonly triggered by milk. Milk-responsive CD4+ T cells producing type 2 cytokines are present in both diseases, yet the clinical manifestation of disease in milk allergy (MA) and EoE are distinct.

OBJECTIVE

We sought to identify differences in CD4+ T cells between EoE and MA that may be responsible for distinct disease manifestations.

METHOD

The total and milk-specific CD4+ T-cell phenotype of children with MA, children with EoE (active or in remission), and controls was measured using spectral flow cytometry of peripheral blood (all groups) or esophageal biopsies (EoE and control).

RESULTS

Circulating milk-responsive T cells could be identified in active EoE and MA. An increased frequency of TH2A cells was also noted in MA and EoE. In circulating T cells, type 2 cytokine production was elevated in MA, but not EoE. Within the milk-responsive T follicular helper (TFH) subset, a dichotomy of phenotype was noted: TFH13 cells predominated in MA, while IL-10-producing TFH cells predominated in EoE. In the esophagus, CD4+ T cells were constitutively activated and expressed not only type 2 cytokines, but also IL-10 and IL-21 in active EoE. IgG4 was produced from CD38+ plasma cells in close proximity to CD4+ T cells. In vitro activation studies demonstrated that IL-10 and IL-21 elicited strong IgG4 responses in B lymphocytes, while IL-4 and IL-13 promoted IgE production.

CONCLUSIONS

Our studies demonstrate a dichotomy of TFH responses that may be the basis for different clinical manifestations to milk in EoE and MA.

Factors influencing the natural history of non-IgE-mediated gastrointestinal food allergies in paediatric age: a prospective multicentre cohort study

BACKGROUND

We aimed at identifying the factors influencing the natural history of non-IgE-mediated gastrointestinal food allergies (non-IgE-GIFA), a group of common paediatric conditions including food protein-induced: enteropathy (FPE), allergic proctocolitis (FPIAP), enterocolitis syndrome (FPIES), and motility disorders (FPIMD).

METHODS

Prospective multicentre cohort study involving paediatric patients (both sexes, aged ≤14 y) with non-IgE-GIFA diagnosed and followed for 24 months at a Tertiary Centre for Paediatric Allergy, Gastroenterology and Nutrition. Anamnestic and clinical data were collected from all enrolled patients.

RESULTS

123 non-IgE-GIFA patients were enrolled (56% male, median age (IQR) 150 (60-300) days): FPE (39%), FPIES (17%), FPIAP (16%) and FPIMD (28%). 42% of patients had multiple food allergies (FAs) at baseline, and 64% had a positive family history of allergy. Male sex (OR = 2.24, 95% CI 1.07 to 4.71) and every 1 month of diagnostic delay (OR=1.09, 95% CI 1.01 to 1.18) were positively associated with the occurrence of multiple FAs. At 24-month follow-up, 54% of patients acquired immune tolerance. This rate was higher in FPIAP (75%), when compared with FPIMD (62%), FPE (54%) and FPIES (24%). The odds of 24-month immune tolerance acquisition rate was lower in children with family history of allergy (OR=0.41, 95% CI 0.19 to 0.89) and in those with multiple FAs at baseline (OR=0.24, 95% CI 0.11 to 0.51). At 24-month follow-up, the rate of patients with allergic march was 0.46 (95% CI 0.38 to 0.55, n=57/123), without differences comparing the four phenotypes. The presence of multiple FAs at baseline was associated with an increased risk of developing allergic march (OR=2.22, 95% CI 1.07 to 4.61) at 24-month follow-up.

CONCLUSIONS

The results of the study suggest the potential role of modifiable and non-modifiable risk factors influencing the natural history of paediatric patients affected by non-IgE-GIFA.

Oral Exposure to Clostridium difficile Toxin A Aggravates Food Allergy by Intestinal Barrier Destruction, Mast Cell Activation, and Th2-Biased Immune Responses

Food allergy is a complex disease, with multiple environmental factors involved. Considering the regulatory effect of Clostridium difficile toxin A (Tcd A) on biological processes of allergic reactions, the role of oral exposure to Tcd A on food allergy was investigated. The intestinal permeability and β-hexosaminidase were promoted by Tcd A using the in vitro Caco-2 and HT-29 cells coculture monolayer and bone marrow-derived mast cell (MCs) degranulation model. When the sensitized mice were challenged with OVA and 4 μg of Tcd A, specific IgE and MCPT-1 levels were increased. The results of flow cytometry and ELISA demonstrated that the Th1 and Treg cells were reduced and higher IL-5 was induced. The jejunum staining showed that villus injury and MC accumulation were aggravated. All of the findings demonstrated that Tcd A could aggravate food allergy, and the orally exposed risk factors aggravating food allergy warrant increasing attention.

Corydalis yanhusuo extract and its pharmacological substances alleviate food allergy by inhibiting mast cells activation via PLC/PKC/STAT3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Food allergies have increasingly become a disease that affects global health and need for corresponding therapeutic drugs urgently. As a traditional Chinses medicine with a wide range of pharmacological effects, however, there was no clear research confirming therapeutic effect and pharmacological substances of Corydalis yanhusuo (YHS) on food allergies. Mast cells (MCs) are the main effector cells which mediate allergic and pseudo-allergic reactions.

MATERIALS AND METHODS

In this study, we investigated the effect of YHS extract on treating food allergy and its underlying mechanism. The inhibitory effect of YHS on MCs activation in vitro was evaluated by Ca2+ influx, degranulation, and cytokine release detection. The in vivo effect was investigated using the passive cutaneous anaphylaxis (PCA), active systemic allergy as well as OVA-induced food allergy mice. Western blot was performed to reveal the signaling pathway.

RESULTS

YHS extract showed an inhibitory effect on MCs activation and food allergy both in vitro and in vivo. PLC/PKC/STAT3 signaling pathway was suppressed by YHS extract in the disease. HPLC analysis revealed YHS extract contains corydaline and tetrahydropalmatine, and both compounds inhibited MCs activation induced by C48/80 in vitro.

CONCLUSION

YHS extract inhibited the MCs activation and food allergy via PLC/PKC/STAT3 pathway.

IL-33 signaling is dispensable for the IL-10-induced enhancement of mast cell responses during food allergy

Background

The IL-33/ST2 axis plays a pivotal role in the development of IgE-mediated mast cell (MC) responses during food allergy. We recently demonstrated that the pleiotropic cytokine, IL-10, not only exerts proinflammatory effects on IgE-mediated MC activation, but also promotes IL-33-induced MC responses. However, whether IL-33 is necessary for IL-10's proinflammatory effects has not been examined.

Methods

To therefore determine the role of the IL-33/ST2 axis in this pathway, we assessed the effects of IL-10 on IgE-mediated MC activation and food allergy development in wild-type (WT) and ST2-/- mice.

Results

IL-10 stimulation significantly enhanced IL-33 gene expression, ST2 receptor expression, cytokine production, mMCP-1 secretion, and proliferation in IgE and antigen-activated bone marrow-derived MCs (BMMCs) from WT mice. ST2-/- BMMCs exhibited reduced cytokine secretion in response to IgE-dependent activation. However, IL-10 enhanced cytokine production, mMCP-1 secretion, and proliferation in these cells as well. To further assess the role of IL-10, food allergy was induced in WT and ST2-/- mice subjected to antibody-mediated IL-10 depletion. IL-10-depleted WT mice exhibited a significant attenuation in MC-mediated responses to OVA challenge. While ST2-/- mice also exhibited a profound suppression of MC responses, IL-10 depletion had no additional effects. However, ST2-/-/IL-10-/- mice exhibited further decreases in OVA-IgE and antigen-specific MC activation compared to ST2-/- mice.

Conclusion

Our data demonstrates that IL-10 can enhance MC responses in both WT and ST2-/- mice, further corroborating its proinflammatory effects on MCs and suggesting that they are not regulated by IL-33 signaling.

Insights into self-reported food allergies in Romanian schoolchildren

The prevalence of food allergy (FA) varies worldwide with an increasing rate in the last decades. Data of self-reported FA have been recorded by most European countries, the US, Canada and Australia, but not Romania. The aim of this study is to analyze the prevalence and severity of FA and to assess the extent of information the medical and teaching staff in schools have on students' medical history.

METHODS

A cross-sectional survey was performed in schoolchildren from Cluj-Napoca, Romania, using an online questionnaire delivered to their parents.

RESULTS AND CONCLUSIONS

Seven hundred and eight individuals completed the entire questionnaire. The prevalence of self-reported FA was 8.9%, 28.6% presented food-induced angioedema and 38.1% required ER presentation. Cow milk (36.5%), egg (9.5%), strawberry (20.6%) and nuts (2.7%)were the most frequent culprit foods. The lack of an appropriate and accurate communication with the medical and teaching staff in the school suggest the requirement for further measures for parents and children educations regarding food allergy detection and management.

Allergen sensitization patterns: Allergic rhinitis with multimorbidity versus alone-A real-world study

BACKGROUND

Allergic rhinitis (AR) multimorbidity may need to be considered a specific disease because of distinct clinical and immunological differences from AR alone. Allergic multimorbidity often involves polysensitization, where allergen-specific immunoglobulin E (IgE) plays a significant role.

OBJECTIVE

This study aims to explore differences in allergen IgE sensitization patterns between AR alone and AR multimorbidity.

METHODS

A real-world case-control study was conducted with patients diagnosed with AR. Multivariate logistic regression analyzed the associations between AR multimorbidity and allergen sensitivity, allergen-specific IgE levels, and the count of positive allergens.

RESULTS

A cohort of 2275 patients with AR was included, of which 1100 (48.4%) presented with AR alone, while 1175 (51.6%) exhibited AR multimorbidity. Patients with AR multimorbidity had a more diverse allergen profile than those with AR alone. An increased number of positive ingested allergens had a higher odds ratio (OR) for AR multimorbidity compared with inhaled allergens (1.46 vs. 1.96) across all phenotypes. Sensitization to allergens and their allergen-specific IgE levels, including dust mites, cat dander, and milk (p < 0.05), were associated with AR multimorbidity. In children, cat and dog dander were significant allergens associated with AR multimorbidity (p < 0.05).

CONCLUSIONS

Allergen sensitization patterns in AR multimorbidity differ from those in AR alone. Polysensitization, particularly to ingested allergens, increases the risk of allergic multimorbidity. The risk of allergic multimorbidity also increases with specific allergen positivity and higher allergen-specific IgE levels.

Research progress and immunological insights of shrimp allergens

Allergic diseases have become a major health issue in the 21st century. The FAO has pinpointed the eight most prevalent allergens worldwide, with shrimp allergy attracting global concern due to its escalating incidence. This review delves into the current knowledge of shrimp allergen types and traits, immune response mechanisms, advancements in cross-reactivity research, and breakthroughs in diagnostic and therapeutic methods. It highlights the variety of shrimp allergens, such as tropomyosin and arginine kinase, and concentrates on IgE-mediated immediate hypersensitivity reactions, involving mast cells and basophils, alongside the role of T cells and cytokines in non-IgE-mediated delayed hypersensitivity reactions. The exploration of cross-reactivity underscores the connection between shrimp allergy and allergies to other animals. Utilizing bioinformatics tools, including homology analysis, epitope prediction, and molecular modeling, has enhanced our comprehension of allergen molecular features. In treatment and diagnosis, innovative approaches like immunotherapy and gene editing technology hold potential to decrease allergic sensitivity, while emerging reduction techniques like heat treatment and enzymatic hydrolysis offer new strategies for the prevention and management of food allergies. The evolution of allergen detection and purification technologies has spurred innovation in testing methodologies, encompassing traditional in vivo tests like SPT and DBPCFC, in addition to a range of other techniques such as immunoassays, biochip technology, PCR, and histamine release experiments, propelling the instantaneous and accurate identification of allergens. These scientific breakthroughs not only expand our understanding of shrimp allergen biology but also lay the foundation for developing more effective allergy prevention and control strategies.

Therapeutic and continuative effects of human umbilical cord-derived mesenchymal stromal cells in food-allergic mice

This study aimed to investigate the impact of human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs) on food allergy (FA) mice induced by ovalbumin. The percentage of regulatory T cells (Tregs) was assessed by administering hUC-MSCs intravenously to FA mouse models with oral challenges, allergic responses and levels of related allergic cytokines. The phenotypes of hUC-MSCs were analysed using flow cytometric analysis. Immunohistochemistry was used for histology observation. Real-time polymerase chain reaction (PCR) was used for gene expression. Jejunum tissue was analysed by transcriptome sequencing. Our results demonstrated that in the current FA model, hUC-MSC therapy significantly alleviated allergic responses and diarrhoea. Levels of immunoglobulin E (IgE), as well as cytokines, such as interleukin (IL)-6 and tumour necrosis factor-α associated with T helper 2 cells, were reduced. Conversely, transforming growth factor (TGF)-β levels increased with hUC-MSC therapy. In addition, enhanced TGF-β expression along with IL-10 messenger ribonucleic acid levels and an increased percentage of CD4+Foxp3+ Tregs were observed. In long-term FA mice models, hUC-MSC therapy exhibited sustained effects in mitigating rectal temperature decrease and mortality rates while reducing the levels of IgE, IL-6 and proportion of IgE+ cells; it also elevated TGF-β levels. Furthermore, hUC-MSC therapy attenuated pathological injury in both current and long-term FA mouse models. Transcriptome sequencing showed that upregulated differentially expressed genes were mainly concentrated in neural activation-ligand interaction, the cyclic guanosine monophosphate-protein kinase G signalling pathway and the TGF-β signalling pathway. The hUC-MSC therapy holds promise for alleviating both immediate and persistent FA conditions; targeting TGF-β and IL-10 secreted by hUC-MSCs may be a potential approach for treating FA.

Terpenoids, a Rising Star in Bioactive Constituents for Alleviating Food Allergy: A Review about the Potential Mechanism, Preparation, and Application

Food allergies affect approximately 2.5% of the global population, with a notable increase in prevalence observed each year. Terpenoids, a class of natural bioactive constituents, have been widely utilized in the management of immune- and inflammation-related disorders, and their potential in alleviating food allergies is increasingly being recognized. This article summarizes various terpenoids derived from plant, fungal, and marine sources. Among them, triterpenoids, such as oleanolic acid, ursolic acid, and lupeol, possess the highest proportion and bioactivity in alleviating food allergy. Additionally, the mechanisms by which terpenoids may mitigate allergic diseases were categorically outlined, focusing on their roles in epithelial mucosal barrier function, immunomodulatory effects during the sensitization phase, inhibition of effector cells, oxidative stress, and regulation of microbial homeostasis. Finally, the advantages and limitations of natural extraction and artificial synthesis methods were compared, and the application of terpenoids in the food industry were also discussed. This article serves as a useful reference for the development of methods or functional foods based on terpenoids, which could represent a promising avenue for alleviating food allergy.

Allergenicity assessment of β-lactoglobulin ferulic acid-glucose conjugates

We prepared the β-lactoglobulin (BLG)-ferulic acid (FA)-glucose (Glu) conjugates by alkaline method and Maillard reaction to assess the allergenicity. FA and Glu can form a ternary covalent conjugate with BLG, as evidenced by the shortening of SEC retention time, upward migration of SDS-PAGE protein bands, considerable decrease in free amino and sulfhydryl content, and changes in multistructure. BLG-Glu-FA conjugates weakly bound to immunoglobulin E in allergic sera was weak, reduced interleukin 4 and tumor necrosis factor α levels in RBL-2H3 cells and histamin and interleukin 6 secretion levels in KU812 cells, and inhibited the nuclear factor-κB signaling pathway. In vivo experiments showed that the conjugates regulated T-cell homeostasis in mouse splenic and mesenteric lymphocytes and attenuated splenic and duodenal immune injury. Therefore, the conjugates of BLG with FA combined with Glu altered the epitope structure and exhibited low allergenicity.

Feeding Docosahexaenoic Acid and Arachidonic Acid during Suckling and Weaning Contributes to Oral Tolerance Development by Beneficially Modulating the Intestinal Cytokine and Immunoglobulin Levels in an Allergy-Prone Brown Norway Rat Model

BACKGROUND

Suckling and weaning arachidonic acid (ARA) + docosahexaenoic acid (DHA) supplementation promoted oral tolerance (OT) development in pups, however, the effect of it on the intestine to promote OT development remains unknown.

OBJECTIVE

We aimed to explore the impact of this supplementation on intestinal fatty acid composition, structure, and indicators that are supportive of OT development.

METHODS

Allergy-prone Brown Norway dams were randomly assigned to a control (0% ARA, 0% DHA) or ARA + DHA diet (0.45% ARA, 0.8% DHA) during suckling (0-3 wk). At weaning (3-8 wk), offspring were randomly assigned to a control (0% ARA, 0% DHA) or ARA + DHA diet (0.5% ARA, 0.5% DHA). At 3 wk, offspring in each group received an oral gavage of sucrose or ovalbumin (OVA) solution for five consecutive days. At 7 wk, all offspring received an intraperitoneal OVA injection. At 8 wk, offspring were terminated to evaluate jejunum morphology and measure mucosal food allergy-related secretory immunoglobulin A (sIgA) and cytokines, ileum phospholipid and triglyceride fatty acid compositions, and fecal calprotectin.

RESULTS

Weaning ARA + DHA resulted in a higher percentage of DHA in ileum phospholipids and triglycerides (both P < 0.001), without affecting the percentage of ARA. Despite no lasting effect of suckling ARA + DHA on the DHA content in ileum phospholipids, a programming effect was found on the allergy-related intestinal immune profile [higher concentrations of mucosal IL-2 (P = 0.049) and sIgA (P = 0.033)]. OVA treatment resulted in a lower concentration of mucosal IL-6 (P = 0.026) regardless of dietary interventions. Offspring fed ARA + DHA during suckling and/or weaning had a higher concentration of mucosal transforming growth factor-beta (TGF-β) after OVA treatment but this was not observed in offspring fed control diets during suckling and weaning (P = 0.04).

CONCLUSIONS

Early life dietary ARA + DHA supplementation to allergy-prone rats enhanced the DHA concentration in intestinal phospholipids (weaning period) and increased the mucosal sIgA, IL-2, and TGF-β levels (suckling and weaning period), indicating its ability to create a tolerogenic intestinal environment to support OT development.

Evaluation of a direct lymphocyte proliferation test for the diagnosis of canine food allergies with delayed reactions after oral food challenge

BACKGROUND

In humans, food allergies (FAs) are divided into those with immunoglobulin (Ig) E-mediated (immediate FA), cell-mediated (delayed FA) or both mechanisms (mixed FA). In dogs, lymphocyte stimulation tests have the highest concordance with oral food challenges (OFCs).

OBJECTIVES

To report the evaluation of a lymphocyte proliferation test (LPT) in dogs with FA and delayed reactions (≥6 h) after OFC.

ANIMALS

Thirty-five healthy and 28 dogs with delayed FA.

MATERIALS AND METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated and automatically counted before and after a 5-day culture with food allergens. Stimulation indices (SIs) were then calculated. Food allergen-specific IgE was quantified using the Pet Allergy Xplorer (PAX).

RESULTS

None of the 10 healthy laboratory beagles and 25 healthy pet dogs had an SI greater than the 3.0 cut-off, indicating a specificity of 100%. All 28 dogs with delayed FA had at least one positive stimulation to a food item that induced delayed flares after OFC; the sensitivity of this LPT for the identification of delayed canine FA was 100%. The LPT correctly identified 57 of 68 food items causing delayed flares after OFC (84%). The PAX was negative for food-specific IgE in 18 of the 28 dogs (64%), as expected for delayed FA. In three dogs (11%), PAX results overlapped with those of the LPT, suggesting a mixed FA.

CONCLUSIONS AND CLINICAL RELEVANCE

Food allergies with delayed reactions after OFC-those suspected of having a cell-mediated mechanism-seemed to be the most common type of FA in the studied dogs. The LPT was helpful in identifying such cases.

Quantifying allergenic proteins using antibody-based methods or liquid chromatography-mass spectrometry/mass spectrometry: A review about the influence of food matrix, extraction, and sample preparation

Accurate quantification of allergens in food is crucial for ensuring consumer safety. Pretreatment steps directly affect accuracy and efficiency of allergen quantification. We systematically reviewed the latest advances in pretreatment steps for antibody-based methods and liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) protein quantification methods in food. For antibody-based methods, the effects induced by food matrix like decreased allergen solubility, epitope masking, and nonspecific binding are of the upmost importance. To mitigate interference from the matrix, effective and proper extraction can be used to obtain the target allergens with a high protein concentration and necessary epitope exposure. Removal of interfering substances, extraction systems (buffers and additives), assistive technologies, and commercial kits were discussed. About LC-MS/MS quantification, the preparation of the target peptides is the crucial step that significantly affects the efficiency and results obtained from the MS detector. The advantages and limitations of each method for pre-purification, enzymatic digestion, and peptide desalting were compared. Additionally, the application characteristics of microfluidic-based pretreatment devices were illustrated to improve the convenience and efficiency of quantification. A promising research direction is the targeted development of pretreatment methods for complex food matrices, such as lipid-based and carbohydrate-based matrices.

Structural characterization and mast cell stabilizing activity of Red-edge tea polysaccharide

The potential anti-allergic properties of tea have been demonstrated in studies supporting theanine and catechin. However, research on tea polysaccharides' anti-allergic properties has been limited. In this study, we extracted red-edge tea crude polysaccharide (RETPS) and evaluated its anti-allergic activity using the mast cell, passive cutaneous anaphylaxis, and passive systemic anaphylaxis models. We purified RETPS using the DEAE-52 cellulose column, analyzed its composition and structural characteristics, and compared the anti-allergic properties of different polysaccharide fractions. The purified components RETPS-3 and RETPS-4 displayed higher galacturonic acid content and lower molecular weight (106.61 kDa and 53.95 kDa, respectively) compared to RETPS (310.54 kDa). In addition, RETPS-3 and RETPS-4 demonstrated superior anti-allergic activity than RETPS in mice's passive cutaneous and systemic allergic reactions. Our findings provide evidence of the anti-allergic potential of tea polysaccharides and offer a theoretical foundation for developing tea polysaccharides as a functional anti-allergic food product.

Early-Life Milk αS1-Casein Allergy Induces the Activation of Astrocytes in Mice and Leads to Stress Vulnerability in Adulthood

In recent years, the incidence of food allergies in children has been increasing annually, significantly affecting the quality of life for patients and their families. It has long been suspected that childhood allergies might potentially lead to behavioral and psychological issues in adulthood, but the specific connection remains unclear. In this study, we established a model of young mice allergic to milk αS1-casein, conducted behavioral tests, and employed transcriptomics, immunohistochemistry, Golgi staining, and fecal microbiota transplantation to explore the link between early life allergies and adult psychological problems. The results showed that early life milk protein allergy significantly increased intestinal epithelial permeability in mice, leading to the translocation of gut microbiota metabolites. This process subsequently activated astrocyte lysosomes via SLC15a3, making astrocytes more susceptible. This susceptibility caused mice with early life milk protein allergy to have more activated astrocytes and excessive dendritic spine phagocytosis (normal group: 5.4 ± 1.26 spines/10 μm, allergy group: 3.2 ± 0.92 spines/10 μm) under acute stress in adulthood, leading to anxiety and depressive behaviors.

IBD functions as a double-edged sword for food allergy in BALB/c mice model

Inflammatory bowel disease (IBD) and food allergy (FA) increase in tandem, but the potential impact of IBD on FA remains unclear. We sought to determine the role of IBD on FA. We first assessed the changes of FA-related risk factors in dextran sulphate sodium salt (DSS) induced colitis mice model. Then, we evaluated the role of IBD on FA in mice. FA responses were determined using a clinical allergy score, body temperature change, serum antibody levels, cytokines level and mouse mast cell protease 1 (MMCP-1) concentration. Accumulation of regulatory T cells was tested using flow cytometry. Intestinal changes were identified by histology, immunohistochemistry, gene expression and gut microbial community structure. In DSS-induced colitis mice model, we found the intestinal damage, colonic neutrophil infiltration, and downregulation of splenic Th2 cytokines and Tregs in mesenteric lymph nodes (MLN). Moreover, we also found that IBD can alleviate the FA symptoms and lead to the significant downregulation of Th2 cytokines, serum IgE and MMCP-1. However, IBD exacerbates intestinal injury and promotes the gene expression levels of IL-33 and IL-5 in the small intestine, damages the intestinal tissue structure and aggravates intestinal dysbiosis in FA. IBD functions as a double-edged sword in FA. From the perspective of clinical symptoms and humoral immune responses, IBD can reduce FA response by downregulating Th2 cytokines. But from the perspective of the intestinal immune system, IBD potentially disrupts intestinal tolerance to food antigens by damaging intestinal tissue structure and causing intestinal dysbiosis.

Atopic dermatitis and food allergy: More than sensitization

The increased risk of food allergy in infants with atopic dermatitis (AD) has long been recognized; an epidemiologic phenomenon termed "the atopic march." Current literature supports the hypothesis that food antigen exposure through the disrupted skin barrier in AD leads to food antigen-specific immunoglobulin E production and food sensitization. However, there is growing evidence that inflammation in the skin drives intestinal remodeling via circulating inflammatory signals, microbiome alterations, metabolites, and the nervous system. We explore how this skin-gut axis helps to explain the link between AD and food allergy beyond sensitization.

Effect of Thermal Processing on Food Allergenicity: Mechanisms, Application, Influence Factor, and Future Perspective

Thermally processed foods are essential in the human diet, and their induced allergic reactions are also very common, seriously affecting human health. This review covers the effects of thermal processing on food allergenicity, involving boiling, water/oil bath heating, roasting, autoclaving, steaming, frying, microwave heating, ohmic heating, infrared heating, and radio frequency heating. It was found that thermal processing decreased the protein electrophoretic band intensity (except for infrared heating and radio frequency heating) responsible for destruction of linear epitopes and changed the protein structure responsible for the masking of linear/conformational epitopes or the destruction of conformational epitopes, thus decreasing food allergenicity. The outcome was related to thermal processing (e.g., temperature, time) and food (e.g., types, pH) condition. Of note, as for conventional thermal processing, it is necessary to control the generation of the advanced glycation end products in roasting/baking and frying, and the increase of structural flexibility in boiling and water/oil bath heating, autoclaving, and steaming must be controlled; otherwise, it might increase food allergenicity. As for novel thermal processing, the temperature nonuniformity of microwave and radio frequency heating, low penetration of infrared heating, and unwanted metal ion production of ohmic heating must be considered; otherwise, it might be the nonuniformity and low effect of allergenicity reduction and safety problems.

The potential of orally exposed risk factors and constituents aggravating food allergy: Possible mechanism and target cells

Food allergy is a significant concern for the health of humans worldwide. In addition to dietary exposure of food allergens, genetic and environmental factors also play an important role in the development of food allergy. However, only the tip of the iceberg of risk factors in food allergy has been identified. The importance of food allergy caused by orally exposed risk factors and constituents, including veterinary drugs, pesticides, processed foods/derivatives, nanoparticles, microplastics, pathogens, toxins, food additives, dietary intake of salt/sugar/total fat, vitamin D, and therapeutic drugs, are highlighted and discussed in this review. Moreover, the epithelial barrier hypothesis, which is closely associated with the occurrence of food allergy, is also introduced. Additionally, several orally exposed risk factors and constituents that have been reported to disrupt the epithelial barrier are elucidated. Finally, the possible mechanisms and key immune cells of orally exposed risk factors and constituents in aggravating food allergy are overviewed. Further work should be conducted to define the specific mechanism by which these risk factors and constituents are driving food allergy, which will be of central importance to the targeted therapy of food allergy.

Peanut allergen characterization and allergenicity throughout development

Introduction

Peanut allergy (PA) in children is a major concern. There is a need for better biological material for both diagnosis and oral immunotherapy (OIT) treatments. The unique state of seeds at early reproductive stages may affect the allergenicity of storage proteins, and impact clinical diagnostic and OIT protocols. The objective of this study was to evaluate the major allergen content in sequential seed developmental stages and monitor allergenicity via specific IgE binding quantification and skin prick testing.

Methods

Seeds were collected from peanut plants and sorted into five developmental stages: initial (S1), developing (S2), full-size without coloration (S3), full-size with coloration (S4), and fully mature (S5) seeds. Samples were characterized by RNA-Seq, ELISA, and immunohistochemistry. Lyophilized, ground preparations were used for evaluation of skin test responses in sixty challenge-proven PA children.

Results

Gene expression, protein content, and specific IgE binding of allergenic proteins increased throughout seed maturation and development. An expression bias towards the less allergenic A-genome copy of the major allergen Ara h 2 was found in earlier stages, especially in stage S2. Immunohistochemical staining showed that Ara h 2 is more dispersed in the cell and less accumulated within organized bodies at stage S2 versus stage S4. Significant differences were found in mean wheal responses between the commercial peanut extract (equivalent to stage S5) and stages S1 and S2, but not with stage S4, upon skin prick testing in subjects with PA.

Discussion

The observed decrease in peanut-specific IgE binding of immature peanut seeds may be a result not only of decreased amounts of allergenic proteins, but also of profound changes in seed composition and conformation. This may be significant for developing a safer and more effective peanut OIT protocol.

Glutenin from the Ancient Wheat Progenitor Is Intrinsically Allergenic as It Can Clinically Sensitize Mice for Systemic Anaphylaxis by Activating Th2 Immune Pathway

Wheat allergy is a major type of food allergy with the potential for life-threatening anaphylactic reactions. Common wheat, Triticum aestivum (hexaploid, AABBDD genome), was developed using tetraploid wheat (AABB genome) and the ancient diploid wheat progenitor (DD genome)-Aegilops tauschii. The potential allergenicity of gluten from ancient diploid wheat is unknown. In this study, using a novel adjuvant-free gluten allergy mouse model, we tested the hypothesis that the glutenin extract from this ancient wheat progenitor will be intrinsically allergenic in this model. The ancient wheat was grown, and wheat berries were used to extract the glutenin for testing. A plant protein-free colony of Balb/c mice was established and used in this study. The intrinsic allergic sensitization potential of the glutenin was determined by measuring IgE response upon transdermal exposure without the use of an adjuvant. Clinical sensitization for eliciting systemic anaphylaxis (SA) was determined by quantifying the hypothermic shock response (HSR) and the mucosal mast cell response (MMCR) upon intraperitoneal injection. Glutenin extract elicited a robust and specific IgE response. Life-threatening SA associated and a significant MMCR were induced by the glutenin challenge. Furthermore, proteomic analysis of the spleen tissue revealed evidence of in vivo Th2 pathway activation. In addition, using a recently published fold-change analysis method, several immune markers positively and negatively associated with SA were identified. These results demonstrate for the first time that the glutenin from the ancient wheat progenitor is intrinsically allergenic, as it has the capacity to elicit clinical sensitization for anaphylaxis via activation of the Th2 pathway in vivo in mice.

IL-10 Neutralization Attenuates Mast Cell Responses in a Murine Model of Experimental Food Allergy

IgE-mediated mast cell (MC) activation is a critical component of allergic responses to oral Ags. Several T cell-derived cytokines have been shown to promote MC reactivity, and we recently demonstrated a critical role for the cytokine IL-10 in mediating MC responses during food allergy. In this study, we further validate the role of IL-10 using Ab-mediated IL-10 depletion. IL-10 neutralization significantly attenuated MC responses, leading to decreased MC accumulation and activation, as well as inhibition of MC-mediated symptoms such as allergic diarrhea. This was accompanied by decreased Th2 cytokine gene expression, attenuated systemic T cell responses, and fewer CD4 T cells, B cells, and MCs in the spleen. Our data further confirm the role of IL-10 in driving MC responses and suggest that IL-10-responsive MCs may constitute an important player in allergic responses.

Worldwide Heterogeneity of Food Allergy: Focus on Peach Allergy in Southern Italy

Food allergy (FA) has shown an increasing prevalence in the last decades, becoming a major public health problem. However, data on the prevalence of FA across the world are heterogeneous because they are influenced by several factors. Among IgE-mediated FA, an important role is played by FA related to plant-derived food which can result from the sensitization to a single protein (specific FA) or to homologous proteins present in different foods (cross-reactive FA) including non-specific lipid transfer proteins (nsLTPs), profilins, and pathogenesis-related class 10 (PR-10). In addition, the clinical presentation of FA is widely heterogeneous ranging from mild symptoms to severe reactions up to anaphylaxis, most frequently associated with nsLTP-related FA (LTP syndrome). Considering the potential life-threatening nature of nsLTP-related FA, the patient's geographical setting should always be taken into account; thereby, it is highly recommended to build a personalized approach for managing FA across the world in the precision medicine era. For this reason, in this review, we aim to provide an overview of the prevalence of nsLTP-mediated allergies in the Mediterranean area and to point out the potential reasons for the different geographical significance of LTP-driven allergies with a particular focus on the allergenic properties of food allergens and their cross reactivity.

A rapid and sensitive aptamer-based biosensor for beta-lactoglobulin in milk

Beta-lactoglobulin (β-Lg), a prominent milk protein, is a major contributor to milk allergies. The quantitative assessment of β-Lg is a valuable method for assessing the allergenic potential of dairy products. In this study, a specific aptamer, β-Lg-01, with an affinity constant (KD) of 28.6 nM for β-Lg was screened through seven rounds of magnetic bead SELEX (MB-SELEX). A novel bio-layer interferometry (BLI)-based aptasensor was developed, which had a limit of detection (LOD) of 0.3 ng mL-1, a linear range of 1.5 ng mL-1-15 μg mL-1, and a recovery rate of 102-116% among the milk samples. This aptasensor provides a potential tool for the detection and risk assessment of β-Lg within 10 min.

Decoding food reactions: a detailed exploration of food allergies vs. intolerances and sensitivities

The food matrix is a complex system encompassing all constituent elements in food production. It influences the digestibility of these elements through direct interactions and affects the digestive environment. Furthermore, the gastrointestinal system possesses precise mechanisms that efficiently process dietary components into essential nutrients, effectively preventing the onset of abnormal immune responses or dysfunctional host reactions in most instances. However, the incidence of adverse food reactions is constantly increasing, and evidence indicates that this process is environmental. Adverse reactions can be categorized as toxic or nontoxic. Toxic reactions are dose-dependent and can result from natural compounds, processing-induced substances, or contaminants. Nontoxic reactions like food intolerance and hypersensitivity depend on individual susceptibility and evoke specific pathological and physiological responses. This review aims to elucidate the mechanisms underlying the occurrence of immune- (food allergies and sensitivities) and non-immune-mediated (food intolerance) reactions, emphasizing the fundamental distinctions between these two categories. Enhanced comprehension and distinction of these mechanisms will significantly contribute to advancing preventive and therapeutic approaches and establishing guidelines for food labeling concerning immune-mediated reactions.

IL-10 Differentially Promotes Mast Cell Responsiveness to IL-33, Resulting in Enhancement of Type 2 Inflammation and Suppression of Neutrophilia

Mast cells (MCs) play critical roles in the establishment of allergic diseases. We recently demonstrated an unexpected, proinflammatory role for IL-10 in regulating MC responses. IL-10 enhanced MC activation and promoted IgE-dependent responses during food allergy. However, whether these effects extend to IgE-independent stimuli is not clear. In this article, we demonstrate that IL-10 plays a critical role in driving IL-33-mediated MC responses. IL-10 stimulation enhanced MC expansion and degranulation, ST2 expression, IL-13 production, and phospho-relA upregulation in IL-33-treated cells while suppressing TNF-α. These effects were partly dependent on endogenous IL-10 and further amplified in MCs coactivated with both IL-33 and IgE/Ag. IL-10's divergent effects also extended in vivo. In a MC-dependent model of IL-33-induced neutrophilia, IL-10 treatment enhanced MC responsiveness, leading to suppression of neutrophils and decreased TNF-α. In contrast, during IL-33-induced type 2 inflammation, IL-10 priming exacerbated MC activity, resulting in MC recruitment to various tissues, enhanced ST2 expression, induction of hypothermia, recruitment of eosinophils, and increased MCPT-1 and IL-13 levels. Our data elucidate an important role for IL-10 as an augmenter of IL-33-mediated MC responses, with implications during both allergic diseases and other MC-dependent disorders. IL-10 induction is routinely used as a prognostic marker of disease improvement. Our data suggest instead that IL-10 can enhance ST2 responsiveness in IL-33-activated MCs, with the potential to both aggravate or suppress disease severity depending on the inflammatory context.

Biofabrication's Contribution to the Evolution of Cultured Meat

Cultured Meat (CM) is a growing field in cellular agriculture, driven by the environmental impact of conventional meat production, which contributes to climate change and occupies ≈70% of arable land. As demand for meat alternatives rises, research in this area expands. CM production relies on tissue engineering techniques, where a limited number of animal cells are cultured in vitro and processed to create meat-like tissue comprising muscle and adipose components. Currently, CM is primarily produced on a small scale in pilot facilities. Producing a large cell mass based on suitable cell sources and bioreactors remains challenging. Advanced manufacturing methods and innovative materials are required to subsequently process this cell mass into CM products on a large scale. Consequently, CM is closely linked with biofabrication, a suite of technologies for precisely arranging cellular aggregates and cell-material composites to construct specific structures, often using robotics. This review provides insights into contemporary biomedical biofabrication technologies, focusing on significant advancements in muscle and adipose tissue biofabrication for CM production. Novel materials for biofabricating CM are also discussed, emphasizing their edibility and incorporation of healthful components. Finally, initial studies on biofabricated CM are examined, addressing current limitations and future challenges for large-scale production.

Tolerance induction through early feeding to prevent food allergy in infants and children with sensitization against food allergens (TIFFANI): rationale, study design, and methods of a randomized controlled trial

BACKGROUND

Children with sensitization against foods have to be orally food-challenged before eating these foods for the first time. However, the waiting time for an oral food challenge (OFC) in Germany is about 3-6 months. In contrast, there are hints that an early introduction of allergenic foods might be protective regarding the development of food allergy. The aim of this clinical trial is therefore to investigate, whether an introduction and regular consumption of small amounts of food allergens is safe and will result in an increase of tolerance in children with sensitization against food allergens with unknown clinical relevance.

METHODS

In this randomized, placebo-controlled, double-blind, single-center trial, 138 children (8 months to 4 years of age) sensitized to the target allergen(s) hen's egg, cow's milk, peanuts, and/or hazelnuts with unknown clinical relevance will be randomized in a 1:1 ratio to either an active or a placebo group, daily receiving a rusk-like biscuit powder with or without the target allergen(s) for 3-6 months until an OFC will be performed in routine diagnostics. The primary endpoint is an IgE-mediated food allergy to the primary target allergen, after the interventional period.

DISCUSSION

Children with sensitization against food allergens with unknown clinical relevance often have to avoid the corresponding foods for several months until an OFC is performed. Therefore, the "window of opportunity" for an early preventive introduction of allergenic foods might be missed. This trial will assess whether an introduction of small allergen amounts will favor tolerance development in these children.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00032769. Registered on 02 October 2023.

Higher Potential Sensitization of Cow αS1-Casein over Goat αS1-Casein in a Mouse Model due to Enhanced Dendritic Cell Uptake and Activation

Cow's milk allergy is a common food allergy, with the milk protein αS1-casein being a major allergen. This study aimed to investigate differences in sensitization between cow and goat αS1-CN. Cow and goat αS1-CN were labeled with fluorescent dyes and given to mice sensitized with cholera toxin adjuvant. Both proteins reached immune organs, suggesting no major difference in digestion. However, compared with goat αS1-CN, cow αS1-CN is more readily taken up by dendritic cells, inducing dendritic cell maturation. Furthermore, cow αS1-CN can more effectively induce the generation of Th2 cells, leading to a higher production of specific IgE. In a Caco-2/RBL-2H3 cell model, cow αS1-CN caused more mast cell degranulation and loss of epithelial barrier integrity than goat αS1-CN. In summary, this study found differences in immune responses between cow and goat milk αS1-CN. Cow αS1-CN elicited stronger dendritic cell and Th2 responses, leading to increased mast cell degranulation.

Long-term exposure from perinatal life to food-grade TiO2 alters intestinal homeostasis and predisposes to food allergy in young mice

BACKGROUND

Food allergy (FA) is an inappropriate immunological response to food proteins resulting from an impaired induction of oral tolerance. Various early environmental factors can affect the establishment of intestinal homeostasis, predisposing to FA in early life. In this context, we aimed to assess the effect of chronic perinatal exposure to food-grade titanium dioxide (fg-TiO2 ), a common food additive.

METHODS

Dams were fed a control versus fg-TiO2 -enriched diet from preconception to weaning, and their progeny received the same diet at weaning. A comprehensive analysis of baseline intestinal and systemic homeostasis was performed in offspring 1 week after weaning by assessing gut barrier maturation and microbiota composition, and local and systemic immune system and metabolome. The effect of fg-TiO2 on the susceptibility of progeny to develop oral tolerance versus FA to cow's milk proteins (CMP) was performed starting at the same baseline time-point, using established models. Sensitization to CMP was investigated by measuring β-lactoglobulin and casein-specific IgG1 and IgE antibodies, and elicitation of the allergic reaction by measuring mouse mast cell protease (mMCP1) in plasma collected after an oral food challenge.

RESULTS

Perinatal exposure to fg-TiO2 at realistic human doses led to an increased propensity to develop FA and an impaired induction of oral tolerance only in young males, which could be related to global baseline alterations in intestinal barrier, gut microbiota composition, local and systemic immunity, and metabolism.

CONCLUSIONS

Long-term perinatal exposure to fg-TiO2 alters intestinal homeostasis establishment and predisposes to food allergy, with a clear gender effect.

Food protein-induced allergic proctocolitis in infants is associated with low serum levels of macrophage inflammatory protein-3a

BACKGROUND

Food protein-induced allergic proctocolitis (FPIAP) is a nonimmunoglobulin (IgE)-mediated food hypersensitivity and the exact mechanisms that cause FPIAP are unknown. Chemokines play crucial roles in the development of allergic diseases.

OBJECTIVE

To examine serum levels of a group of chemokines in infants with FPIAP.

METHODS

In 67 infants with FPIAP and 65 healthy infants, we measured serum levels of mucosa-associated epithelial chemokine (MEC/CCL28), thymus-expressed chemokine (TECK/CCL25), CX3CL1 and macrophage inflammatory protein (MIP)-3a/CCL20.

RESULTS

Infants with FPIAP had a lower median value of MIP3a/CCL20 than healthy infants [0.7 (0-222) vs. 4 (0-249) pg/mL, respectively] (p < 0.001). Infants with MIP3a/CCL20 levels ≤0.95 pg/mL have 13.93 times more risk of developing FPIAP than infants with MIP3a/CCL20 levels >0.95 pg/mL. Serum MEC/CCL28, TECK/CCL25, and CX3CL1 levels were similar between the infants with FPIAP and the control group.

CONCLUSION

MIP3a/CCL20 serum levels were reduced in infants with FPIAP compared with healthy controls. Whether this finding has a role in pathogenesis remains to be determined.

Gastrointestinal Comorbidities Associated with Atopic Dermatitis-A Narrative Review

The current understanding of atopic dermatitis (AD) seems to be extending beyond a skin-confined condition frequently associated with allergic comorbidities, as in a number of epidemiological studies, the prevalence rate of a range of illnesses has been determined to be greater in patients with AD, or inversely. In most cases, the reasons for this are vague. A subset of these conditions are gastrointestinal disorders, including food sensitization (FS) and food allergy (FA), eosinophilic esophagitis (EoE) (it is of mixed background, both IgE-dependent and independent), food protein-induced enterocolitis syndrome (FPIES) (it exemplifies an IgE-independent food allergy), Crohn's disease (CD), colitis ulcerosa (CU), celiac disease, irritable bowel syndrome (IBS), and gastroesophageal reflux disease (GERD). In this review, we performed a comprehensive search of the literature using the PubMed database. We addressed the epidemiology of the increased co-occurrence of these diseases with AD and discussed potential causes for this subject. Multiple gastroenterological comorbidities appear to be more common in patients with AD, according to our review. The mechanisms that underlie this phenomenon are largely unknown, highlighting the need for further study in this field.

Nutrition and Disorders of Gut-Brain Interaction

BACKGROUND

Disorders of gut-brain interaction (DGBIs) have a complex pathophysiology that is often characterized by a relationship between food ingestion and triggering of symptoms. Understanding of the underlying mechanisms and the role of nutrients as a therapeutic target are rapidly evolving.

AIMS AND METHODS

We performed a narrative review of the literature using the following keywords, their acronyms, and their associations: nutrients, disorders of gut-brain interaction; functional dyspepsia; malabsorption; irritable bowel syndrome; diarrhea; constipation.

RESULTS

Functional dyspepsia displayed a significant correlation between volume, fat and/or wheat abundance, chemical composition of ingested food and symptoms of early satiety, fullness and weight loss. Carbohydrate malabsorption is related to enzyme deficiency throughout the GI tract. Food composition and richness in soluble vs. non-soluble fibers is related to constipation and diarrhea. The elimination of fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) has a significant and non-unidirectional impact on irritable bowel syndrome (IBS) symptoms.

CONCLUSIONS

Food volume, nutritive and chemical composition, and its malabsorption are associated with symptom generation in DGBIs. Further multicenter, randomized-controlled clinical trials are needed to clarify the underlying pathophysiology.

Purification of Food Allergens from Their Natural Sources: Chromatographic Methods

Isolation of food allergens from natural sources enables their characterization in a naturally occurring state. Low-pressure liquid chromatographic methods can be used to purify such allergens with high purity and yield. In this chapter, we describe the protocol for isolating a nut seed protein from its natural source. Interfering macromolecules such as fats and carbohydrates are removed followed by solubilization and extraction of nut seed proteins. The target protein is purified using a combination of various chromatographic techniques.

Is Wheat Glutenin Extract Intrinsically Allergenic? Evaluation Using a Novel Adjuvant-Free Mouse Model of Systemic Anaphylaxis

Wheat is a prominent allergenic food that can trigger life-threatening anaphylaxis. Presently, it remains unclear whether wheat glutenin (WG) extract possesses inherent sensitization potential independently, without the use of adjuvants, and whether it can sensitize mice to the extent of inducing life-threatening systemic anaphylaxis. In this study, we tested the hypothesis that repeated skin exposures to WG extract without adjuvant will sensitize mice with the resultant anaphylactic reaction upon systemic WG challenge. Balb/c mice were bred and maintained on a strict plant protein-free diet and were repeatedly exposed to a WG extract or vehicle once a week for 9 weeks. WG-specific (s)IgE and total (t)IgE levels were quantified. Mice were challenged with WG extract to induce anaphylactic reactions as measured by hypothermic shock response (HSR) and mucosal mast cell degranulation response (MMCR). We also conducted proteomic analysis of 120 spleen immune markers. These skin-sensitized mice exhibited exposure-dependent IgE responses and near-fatal anaphylaxis upon challenge. Proteomic analysis identified seven dramatically elevated immune biomarkers in anaphylactic mice. These data reveal that WG is intrinsically allergenic, and that chronic skin exposure to WG extract can prime the mice for potentially fatal anaphylaxis.

Allergen Stability in Food Allergy: A Clinician's Perspective

PURPOSE OF REVIEW

The globally rising food allergy prevalence is associated with the urgent need for new disease prevention methods, efficient treatment, and reliable risk assessment methods for characterization of food allergens. Due to inter-individual variations in the digestive system, food allergens are degraded to a different extent in each person. Food processing also influences allergen digestion.

RECENT FINDINGS

In this review, we provide an overview of the digestive system with focus on relevance for food allergy. Main food proteins causing allergic reactions are evaluated, and the combined role of food processing and digestion for allergen stability is highlighted. Finally, clinical implications of this knowledge are discussed. Recent literature shows that allergen digestibility is dependent on food processing, digestive conditions, and food matrix. Digestion affects proteins allergenicity. It is currently not possible to predict the immunogenicity of allergens solely based on protein stability.

Chronic application of alcohol-soluble gluten extract over undamaged skin causes clinical sensitization for life-threatening anaphylaxis via activation of systemic Th2 immune responses in mice

Introduction

Gluten allergy is a major public health problem that is growing at an alarming rate. Specific mechanisms underlying sensitization to gluten remain incompletely understood. Currently, it is unclear whether chronic exposure to alcohol-soluble gluten extract via undamaged skin has the capacity to clinically sensitize mice for life-threatening anaphylaxis. Using an adjuvant-free mouse model, here we tested the hypothesis that chronic application of alcohol-soluble durum gluten (ASDG) extract will clinically sensitize mice for life-threatening anaphylaxis.

Methods

This study was conducted in a gluten-free Balb/c mouse colony that was established and maintained on a plant protein-free diet. Groups of adult female mice were exposed dermally to ASDG extract or vehicle once a week for 9-weeks. Specific (s) and total (t) IgE levels were quantified. Mice were challenged systemically with ASDG to measure symptoms of systemic anaphylaxis. Hypothermic shock response (HSR) and mucosal mast cell degranulation response (MMCR) were determined upon challenge. Spleen Th1, Th2, and other immune markers were quantified.

Results

We found that chronic exposure to ASDG elicited robust elevation of sIgE and tIgE. Systemic challenge with ASDG, but not vehicle, elicited life-threatening anaphylaxis associated with dramatic HSR and MMCR. Correlation analysis demonstrated direct positive inter-relationships among IgE, HSR, and MMCR. Anaphylaxis was associated with significant elevation of prototypic Th2 but not Th1 immune markers in the spleen.

Discussion/Conclusion

Our study collectively demonstrates that ASDG is intrinsically allergenic; and chronic exposure to ASDG via undamaged skin can clinically sensitize mice for life-threatening anaphylaxis via activating the systemic Th2 immune responses.

Targeting different signaling pathways for food allergy regulation and potential therapy: a review

The rising incidence rate of food allergy is attracting more intention. The pathogenesis of food allergy is complex and its definite regulatory mechanism is not utterly understood. Exploring the molecular mechanism of food allergy to help find effective methods that can prevent or treat food allergy is widely necessary. Recently, targeting cellular signaling pathways have been employed as novel approaches to discover food allergy therapy. Supplementing probiotics and bioactive compounds with anti-allergic property are believed feasible approaches for food allergy therapy. These probiotics or bioactive compounds affect food allergy by regulating cellular signaling pathways, and ultimately alleviate food allergy. This review aims to report systematic information about the knowledge of signaling pathways participated in food allergy, the alterations of these signaling pathways during food allergy that treated with probiotics and bioactive compounds are discussed as well. Further studies on the mechanism of signaling pathway network regulating food allergy and the precise action mechanism of probiotics and bioactive compounds are in the urgent need to help develop efficient treatment or complete prevention. We hope to help scientists understand food allergy systematically.

Making good of a tricky start: How IgE and mast cells manage a protective sway in food allergy

The immune and nervous systems respond to dangerous stimuli to maintain homeostasis. In a recent issue of Nature, Florsheim et al. and Plum et al. uncover the crosstalk between immunoglobulin E (IgE)-mast-cell-mediated immune activation and neural responses driving behavioral avoidance of allergenic food.

A comprehensive review on glycation and its potential application to reduce food allergenicity

Food allergens are a major concern for individuals who are susceptible to food allergies and may experience various health issues due to allergens in their food. Most allergenic foods are subjected to heat treatment before being consumed. However, thermal processing and prolonged storage can cause glycation reactions to occur in food. The glycation reaction is a common processing method requiring no special chemicals or equipment. It may affect the allergenicity of proteins by altering the structure of the epitope, revealing hidden epitopes, concealing linear epitopes, or creating new ones. Changes in food allergenicity following glycation processing depend on several factors, including the allergen's characteristics, processing parameters, and matrix, and are therefore hard to predict. This review examines how glycation reactions affect the allergenicity of different allergen groups in allergenic foods.

Influence of Lifestyle and Dietary Habits on the Prevalence of Food Allergies: A Scoping Review

Changes in behavior, lifestyle, and nutritional patterns have influenced many potential risk variables globally. In recent decades, food allergies (FAs) have been elevated to a severe public health issue both in developed countries and developing countries (third-world countries). This study aims to evaluate the effects caused by certain factors such as lifestyle and dietary habits on food allergies, review the association of lifestyle and dietary habit status with FAs, and outline why more people are allergic to food sources as a result of lifestyle changes and dietary habits. We searched electronic international databases including Scopus, PubMed, Google Scholar, and Web of Science using combinations of keywords. Utilizing Excel, the relevant studies were included and the irrelevant studies were excluded, and Mendeley was used for referencing and also to remove duplicates. The framework proposed by Arksey and O'Malley was used for this scoping review. The papers published in the databases from 2016 to 2020 were extracted. A total of eight studies were extracted, and this scoping review was carried out according to the risk factors. In our review, we found that some lifestyle choices (Caesarean section and antibiotics) and dietary habits (n-3 PUFA, fast food, duration of dietary intervention, and vitamin D), were important contributing factors for FA.