Food Allergy: Our Evolving Understanding of Its Pathogenesis, Prevention, and Treatment

Advances in conventional and innovative anti-allergic agents for managing food allergies: from mechanisms to challenges

Food allergies constitute a significant and escalating global public health issue. Over the past decade, efforts have intensified to prevent and treat these allergies, including exploring new anti-allergic agents and natural bioactive compounds with minimal side effects. Despite progress, consensus on effective strategies remains elusive. This study undertakes a comprehensive review and discussion of current anti-allergic medications, natural bioactive ingredients, and innovative nano/micro-carriers, focusing on four key mechanisms: binding to allergen epitopes, modulating gut microbiota, restoring intestinal epithelial integrity, and regulating immune responses. Many natural compounds show effectiveness through multiple pathways. Advances in nanotechnology have improved delivery systems such as nanoparticles and sporopollenin exine capsules, enhancing targeted delivery and efficacy. Given the distinct cellular and molecular targets of these anti-allergic agents, investigating synergies between natural and synthetic drugs is essential. For instance, combine traditional anti-allergic drugs with glucocorticoids to quickly relieve initial symptoms; then, use natural agents like probiotics for immune regulation, reducing treatment time and recurrence risk. This review lays the foundation for a scientific framework to guide the future development of combination therapy models in clinical applications.

Regulation of Tert methylation alleviates food allergy via regulating the Tert-IL10 signal pathway

BACKGROUND

The cause of food allergy (FA) is still a mystery. Telomerases are involved in the regulation of immune responses. This study aims to gain an understanding of the contribution of telomerase reverse transcriptase (TERT) to the pathogenesis of FA.

METHODS

A murine FA model was established with ovalbumin as the specific antigen. The role of TERT in regulating dendritic cell (DC) immune tolerogenic functions was evaluated in this murine model.

RESULTS

We observed that the Tert promoter was at demethylation status and the Tert expression was elevated in DCs of FA mice. The Tert expression in DCs had a positive correlation with the FA response. TERT prevented the induction of Il10 expression in DCs. The immune tolerogenic functions of DCs were diminished by TERT. The immune tolerogenic functions of DC were restored by CpG by boosting the Tert promoter methylation. Administration of CpG promoted the therapeutic effects of allergen specific immunotherapy in FA mice.

CONCLUSIONS

Low levels of Il10 expression and high levels of Tert expression were observed in intestinal DCs of FA mice. CpG exposure restored the expression of Il10 and increased the therapeutic benefits of allergen-specific immunotherapy.

Death Due to Anaphylactic Reaction: The Role of the Forensic Pathologist in an Accurate Postmortem Diagnosis

Background and Objectives: The diagnosis of anaphylaxis comprehensively depends on both situational information and laboratory investigations. For this purpose, serum tryptase concentration is examined as an indicator of systemic mast cell mediator release, linked to an underlying anaphylactic process. Increased levels of tryptase may occur in some events different from anaphylaxis, but usually information from crime scene investigations is lacking and autoptic findings are not specific. For legal reasons, it is required to achieve a definite diagnosis of mast cell degranulation that can lead to a certain diagnosis of death from anaphylaxis. Immunohistochemistry seems to be a relatively simple, reliable, and easily repeatable method that can assist the forensic pathologist in the differential diagnosis of death from anaphylaxis. Materials and Methods: This work provides an overview of the current literature on immunohistochemical methods useful in the determination process of anaphylactic-related deaths. A systematic search, according to the PRISMA statement, was performed in databases to identify studies investigating immunohistochemical targets related to anaphylaxis death. Results: This work underscores the importance of anaphylaxis mediators such as tryptase, CD117, and chymase in the immunohistochemical analysis of anaphylactic deaths. Conclusions: According to the reviewed literature, the diagnosis of death due to anaphylaxis should depend not just on the suspicion of an anaphylactic reaction but also on confirming mast cell degranulation through the identification of IHC positivity for inflammatory mediators, particularly in the respiratory tract.

Understanding food allergy through neuroimmune interactions in the gastrointestinal tract

Food allergies are adverse immune reactions to food proteins in the absence of oral tolerance, and the incidence of allergies to food, including peanut, cow's milk, and shellfish, has been increasing globally. Although advancements have been made toward understanding the contributions of the type 2 immune response to allergic sensitization, crosstalk between these immune cells and neurons of the enteric nervous system is an area of emerging interest in the pathophysiology of food allergy, given the close proximity of neuronal cells of the enteric nervous system and type 2 effector cells, including eosinophils and mast cells. At mucosal sites, such as the gastrointestinal tract, neuroimmune interactions contribute to the sensing and response to danger signals from the epithelial barrier. This communication is bidirectional, as immune cells express receptors for neuropeptides and transmitters, and neurons express cytokine receptors, allowing for the detection of and response to inflammatory insults. In addition, it seems that neuromodulation of immune cells including mast cells, eosinophils, and innate lymphoid cells is critical for amplification of the type 2 allergic immune response. As such, neuroimmune interactions may be critical targets for future food allergy therapies. This review evaluates the contributions of local enteric neuroimmune interactions to the underlying immune response in food allergy and discusses considerations for future investigations into targeting neuroimmune pathways for treatment of food allergies.

Allergic Diseases and Childhood Obesity: A Detrimental Link?

Several epidemiological studies have described childhood obesity as a risk factor for atopic disease, particularly asthma. At the same time, this association seems to be more conflicting for allergic rhinitis, atopic dermatitis, and chronic urticaria. This article aims to deepen the possibility of a relationship between childhood obesity and allergic diseases. As regards asthma, the mechanical and inflammatory effects of obesity can lead to its development. In addition, excess adiposity is associated with increased production of inflammatory cytokines and adipokines, leading to low-grade systemic inflammation and an increased risk of asthma exacerbations. Allergic rhinitis, atopic dermatitis, food allergies, and chronic urticaria also seem to be related to this state of chronic low-grade systemic inflammation typical of obese children. Vitamin D deficiency appears to play a role in allergic rhinitis, while dyslipidemia and skin barrier defects could explain the link between obesity and atopic dermatitis. Starting from this evidence, it becomes of fundamental importance to act on body weight control to achieve general and allergic health, disentangling the detrimental link between obesity allergic diseases and childhood obesity. Further studies on the association between adiposity and atopy are needed, confirming the biologically active role of fat tissue in the development of allergic diseases and exploring the possibility of new therapeutic strategies.

The Occurrence of Gluten-Related Antibodies, Sensitization to Selected Food Allergens, and Antibodies against Intrinsic Factor in Adult Patients with Diarrhea-Predominant Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. Due to the possible overlap of IBS clinical symptoms with gluten-related diseases, food allergies, and autoimmune gastritis (AIG), the aim of this study was to present the frequency of anti-tissue transglutaminase 2 (TTG2) autoantibodies, anti-deamidated gluten peptide (DGP) antibodies, specific immunoglobulin E antibodies (sIgE) to selected food allergens, and anti-intrinsic factor (IF) autoantibodies in adult patients with diarrhea-predominant IBS (IBS-D). The study involved 244 patients (170 women) aged 18-75 years. The antibodies were measured with the use of multiparametric immunoassays. Elevated antibody concentrations, irrespective of the class of tested antibody, occurred in 44 patients (17.6%), including 11 patients (4.5%) with positive DGP antibodies, four patients (1.6%) with TTG2 autoantibodies, six patients (2.5%) with IF autoantibodies, and 31 patients (12.7%) with sIgE to food allergens. Sensitization to gluten, proteins from cow's milk, and bovine serum albumin was found in 2.1%, 5.3%, and 9.0% of patients, respectively. Our study showed a high percentage of positive results for the tested antibodies in the IBD-D patients, which indicates the need to perform serological tests for CD, food allergies, and AIG in this group of patients.

Immune regulation by fermented milk products: the role of the proteolytic system of lactic acid bacteria in the release of immunomodulatory peptides

Food allergies have emerged as a pressing health concern in recent years, largely due to food resources and environmental changes. Dairy products fermented by lactic acid bacteria play an essential role in mitigating allergic diseases. Lactic acid bacteria have been found to possess a distinctive proteolytic system comprising a cell envelope protease (CEP), transporter system, and intracellular peptidase. Studying the impact of different Lactobacillus proteolytic systems on the destruction of milk allergen epitopes and their potential to alleviate allergy symptoms by releasing peptides containing immune regulatory properties is a valuable and auspicious research approach. This paper summarizes the proteolytic systems of different species of lactic acid bacteria, especially the correlation between CEPs and the epitopes from milk allergens. Furthermore, the mechanism of immunomodulatory peptide release was also concluded. Finally, further research on the proteolytic system of lactic acid bacteria will provide additional clinical evidence for the possible treatment and/or prevention of allergic diseases with specific fermented milk/dairy products in the future.

Ultrasound-assisted glycation and the allergenicity of α-lactalbumin

BACKGROUND

Ultrasound-assisted glycation is a promising method for decreasing the allergenicity of α-lactalbumin (ALA). However, there is a lack of in vivo studies on the allergenicity of ultrasound-assisted glycated ALA. In this study, the effects of the ultrasound-assisted glycation of ALA on the allergenicity and intestinal microflora were characterized using a BALB/c mouse model.

RESULTS

Increased immunoglobulin -G/ immunoglobulin-E (IgG/IgE) and interleukin-4/6 (IL-4/6) secretions, and reduced interferon-γ (IFN-γ) secretions were found in the serum of ALA sensitized and challenged, mice in comparison with a control group. However, there was no significant difference between the mice fed with ultrasound-assisted glycated ALA and the control group. Mice that were sensitized and challenged with ALA showed disrupted intestinal microflora, manifesting in significantly decreased Firmicutes and significantly increased Proteobacteria. It was found that 100ALA-gal could maintain the intestinal microflora of mice in a normal state. Pearson's rank correlation showed that Proteobacteria and Spirochaetota were correlated positively with the IL-4/IL-6 level and were correlated negatively with the expression of IFN-γ. Proteobacteria were also significantly positively correlated with IL-6 and negatively correlated with IFN-γ (P < 0.05).

CONCLUSION

These results suggested that ultrasound-assisted glycation on ALA can maintain the intestinal microflora in a normal state thus balancing the proportion of Th1/Th2 to decrease allergic reaction. © 2022 Society of Chemical Industry.

Crosstalk between the gut microbiota and innate lymphoid cells in intestinal mucosal immunity

The human gastrointestinal mucosa is colonized by thousands of microorganisms, which participate in a variety of physiological functions. Intestinal dysbiosis is closely associated with the pathogenesis of several human diseases. Innate lymphoid cells (ILCs), which include NK cells, ILC1s, ILC2s, ILC3s and LTi cells, are a type of innate immune cells. They are enriched in the mucosal tissues of the body, and have recently received extensive attention. The gut microbiota and its metabolites play important roles in various intestinal mucosal diseases, such as inflammatory bowel disease (IBD), allergic disease, and cancer. Therefore, studies on ILCs and their interaction with the gut microbiota have great clinical significance owing to their potential for identifying pharmacotherapy targets for multiple related diseases. This review expounds on the progress in research on ILCs differentiation and development, the biological functions of the intestinal microbiota, and its interaction with ILCs in disease conditions in order to provide novel ideas for disease treatment in the future.

Uneventful Coadministration of Seasonal Influenza and COVID-19 BNT162b2 Vaccines Two Weeks Post-Influenza Vaccination in an Egg-Allergic Subject: A Case Report

The COVID-19 pandemic took the world by storm, and although it has taken the world's attention, it did not stop the spread of other communicable diseases. Seasonal influenza is a viral infection that could cause severe disease; therefore, annual influenza vaccination is highly recommended, especially among patients with a weakened immune system. However, such vaccination is contraindicated for people with hypersensitivity to the vaccine or any of its components, e.g., eggs. This paper describes a case of an egg-allergic individual who received an influenza vaccine containing egg protein, which only caused mild tenderness at the site of injection. Two weeks later, the subject received a double vaccination of a second booster dose of Pfizer-BioNTech and the seasonal influenza vaccine. The patient reported no local or systemic adverse reactions to the vaccine. This case report suggests vaccination safety for subjects with mild allergies to vaccine components.

Heart Rate Variability in Subjects with Severe Allergic Background Undergoing COVID-19 Vaccination

Anti-Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccination is the world’s most important strategy for stopping the pandemic. Vaccination challenges the body’s immune response and can be complicated by hypersensitivity reactions. The autonomic nervous system can modulate the inflammatory immune response, therefore constituting a potential marker to characterize individuals at high risk of hypersensitivity reactions. Autonomic nervous system functionality was assessed through measurement of the heart rate variability (HRV) in subjects with a history of severe allergic reactions and 12 control subjects. HRV parameters included the mean electrocardiograph RR interval and the standard deviation of all normal R–R intervals (SDNN). All measurements were performed immediately before the anti-SARS-CoV-2 vaccination. The median RR variability was lower in the study than in the control group: 687 ms (645–759) vs. 821 ms (759–902); p = 0.02. The SDNN was lower in the study group than in the control group: 32 ms (23–36) vs. 50 ms (43–55); p < 0.01. No correlation was found between age and the SDNN. Autonomic nervous system activity is unbalanced in people with a severe allergy background.

Inhibition of pathologic immunoglobulin E in food allergy by EBF-2 and active compound berberine associated with immunometabolism regulation

Introduction

Food allergy is a significant public health problem with limited treatment options. As Food Allergy Herbal Formula 2 (FAHF-2) showed potential as a food allergy treatment, we further developed a purified version named EBF-2 and identified active compounds. We investigated the mechanisms of EBF-2 on IgE-mediated peanut (PN) allergy and its active compound, berberine, on IgE production.

Methods

IgE plasma cell line U266 cells were cultured with EBF-2 and FAHF-2, and their effects on IgE production were compared. EBF-2 was evaluated in a murine PN allergy model for its effect on PN-specific IgE production, number of IgE⁺ plasma cells, and PN anaphylaxis. Effects of berberine on IgE production, the expression of transcription factors, and mitochondrial glucose metabolism in U266 cells were evaluated.

Results

EBF-2 dose-dependently suppressed IgE production and was over 16 times more potent than FAHF-2 in IgE suppression in U266 cells. EBF-2 significantly suppressed PN-specific IgE production (70%, p<0.001) and the number of IgE-producing plasma cells in PN allergic mice, accompanied by 100% inhibition of PN-induced anaphylaxis and plasma histamine release (p<0.001) without affecting IgG1 or IgG2a production. Berberine markedly suppressed IgE production, which was associated with suppression of XBP1, BLIMP1, and STAT6 transcription factors and a reduced rate of mitochondrial oxidation in an IgE-producing plasma cell line.

Conclusions

EBF-2 and its active compound berberine are potent IgE suppressors, associated with cellular regulation of immunometabolism on IgE plasma cells, and may be a potential therapy for IgE-mediated food allergy and other allergic disorders.

Gut microbiota: A target for prebiotics and probiotics in the intervention and therapy of food allergy

Food allergy has become a major public health problem all over the world. Evidence showed that allergic reactions induced by food proteins often lead to disturbances in the gut microbiota (symbiotic bacteria). Gut microbiota plays an important role in maintaining the balance between intestinal immune tolerance and allergic reactions. Dietary intervention has gradually become an important method for the prevention and treatment of allergic diseases, and changing the composition of gut microbiota through oral intake of prebiotics and probiotics may serve as a new effective adjuvant treatment measure for allergic diseases. In this paper, the main mechanism of food allergy based on intestinal immunity was described firstly. Then, the clinical and experimental evidence showed that different prebiotics and probiotics affect food allergy by changing the structure and composition of gut microbiota was summarized. Moreover, the molecular mechanism in which the gut microbiota and their metabolites may directly or indirectly regulate the immune system or intestinal epithelial barrier function to affect food immune tolerance of host were also reviewed to help in the development of food allergy prevention and treatment strategies based on prebiotics and probiotics.

The Meat of the Matter: Understanding and Managing Alpha-Gal Syndrome

Alpha-gal syndrome is an unconventional food allergy, characterized by IgE-mediated hypersensitivity responses to the glycan galactose-alpha-1,3-galactose (alpha-gal) and not to a food-protein. In this review, we discuss how alpha-gal syndrome reframes our current conception of the mechanisms of pathogenesis of food allergy. The development of alpha-gal IgE is associated with tick bites though the possibility of other parasites promoting sensitization to alpha-gal remains. We review the immune cell populations involved in the sensitization and effector phases of alpha-gal syndrome and describe the current understanding of why allergic responses to ingested alpha-gal can be delayed by several hours. We review the foundation of management in alpha-gal syndrome, namely avoidance, but also discuss the use of antihistamines, mast cell stabilizers, and the emerging role of complementary and alternative therapies, biological products, and oral immunotherapy in the management of this condition. Alpha-gal syndrome influences the safety and tolerability of medications and medical devices containing or derived from mammalian products and impacts quality of life well beyond food choices.

Epidemiological survey of self-reported food allergy among university students in China

The aim of this study was to investigate the prevalence of self-reported food allergy among university students in China. A cluster-random sampling population-based cross-sectional study using self - administrated questionnaire was conducted with 2538 college students recruited from 6 universities in China. The questionnaire included data on age, sex, weight, height, FA, comorbid allergic diseases, family history, and understanding food allergy. Data were analyzed by SPSS 25.0 statistical software. Multivariate logistic regression analysis was performed to analyze the risk factors related to self-reported food allergy and estimate the odds ratio. A total of 2538 questionnaires were distributed to the undergraduate students and 2313 completely effective questionnaires were collected, the effective response rate was 91.1%. 834 males and 1479 females were recruited, and their age ranged from 18 to 25 years old. The prevalence of self-reported food allergy was 15.7%, and the rate of doctor-diagnosed food allergy was 8.4%. The leading food allergens included shrimp, shellfish, milk, egg, peach, mango, beef, and peanut, and the prevalence of shrimp allergy was the highest (5.8%). The main clinical manifestation included skin mucous membrane and respiratory symptoms. The prevalence of food allergy were statistically significant difference (P < .05) between different age groups, family history, sun exposure times, smoking, and antibiotic use. Over 45% college students know little about food allergy. The prevalence of self-reported food allergy among Chinese college students was high (15.7%). Shrimp was the main allergenic food, followed by shellfish, milk, egg, peach, and mango. Family history, sun exposure, obesity, and using antibiotics may be the influencing factors of food allergy. The Chinese undergraduates lacked the knowledge about food allergy. Thus, it is necessary to strengthen the health education program on food allergy for college students in China and other middle high-income nations.

The Complex Link and Disease Between the Gut Microbiome and the Immune System in Infants

The human gut microbiome is important for human health. The development of stable microbial communities in the gastrointestinal tract is closely related to the early growth and development of host immunity. After the birth of a baby, immune cells and the gut microbiome mature in parallel to adapt to the complex gut environment. The gut microbiome is closely linked to the immune system and influences each other. This interaction is associated with various diseases in infants and young children, such as asthma, food allergies, necrotizing colitis, obesity, and inflammatory bowel disease. Thus, the composition of the infant gut microbiome can predict the risk of disease development and progression. At the same time, the composition of the infant gut microbiome can be regulated in many ways and can be used to prevent and treat disease in infants by modulating the composition of the infant gut microbiome. The most important impacts on infant gut microbiota are maternal, including food delivery and feeding. The differences in the gut microbiota of infants reflect the maternal gut microbiota, which in turn reflects the gut microbiota of a given population, which is clinically significant.

Food allergy in children-the current status and the way forward

Food allergy in children is a major health concern, and its prevalence is rising. It is often over-diagnosed by parents, resulting occasionally in unnecessary exclusion of some important food. It also causes stress, anxiety, and even depression in parents and affects the family's quality of life. Current diagnostic tests are useful when interpreted in the context of the clinical history, although cross-sensitivity and inability to predict the severity of the allergic reactions remain major limitations. Although the oral food challenge is the current gold standard for making the diagnosis, it is only available to a small number of patients because of its requirement in time and medical personnel. New diagnostic methods have recently emerged, such as the Component Resolved Diagnostics and the Basophil Activation Test, but their use is still limited, and the latter lacks standardisation. Currently, there is no definite treatment available to induce life-long natural tolerance and cure for food allergy. Presently available treatments only aim to decrease the occurrence of anaphylaxis by enabling the child to tolerate small amounts of the offending food, usually taken by accident. New evidence supports the early introduction of the allergenic food to infants to decrease the incidence of food allergy. If standardised and widely implemented, this may result in decreasing the prevalence of food allergy.

Food allergy and hypersensitivity reactions in children and adults-A review

Adverse reactions after food intake are commonly reported and a cause of concern and anxiety that can lead to a very strict diet. The severity of the reaction can vary depending on the type of food and mechanism, and it is not always easy to disentangle different hypersensitivity diagnoses, which sometimes can exist simultaneously. After a carefully taken medical history, hypersensitivity to food can often be ruled out or suspected. The most common type of allergic reaction is immunoglobulin E (IgE)-mediated food allergy (prevalence 5-10%). Symptoms vary from mild itching, stomach pain, and rash to severe anaphylaxis. The definition of IgE-mediated food allergy is allergic symptoms combined with specific IgE-antibodies, and therefore only IgE-antibodies to suspected allergens should be analyzed. Nowadays, methods of molecular allergology can help with the diagnostic process. The most common allergens are milk and egg in infants, peanut and tree nuts in children, and fish and shellfish in adults. In young children, milk/egg allergy has a good chance to remit, making it important to follow up and reintroduce the food when possible. Other diseases triggered by food are non-IgE-mediated food allergy, for example, eosinophilic esophagitis, celiac disease, food protein-induced enterocolitis syndrome, and hypersensitivity to milk and biogenic amines. Some of the food hypersensitivities dominate in childhood, others are more common in adults. Interesting studies are ongoing regarding the possibilities of treating food hypersensitivity, such as through oral immunotherapy. The purpose of this review was to provide an overview of the most common types of food hypersensitivity reactions.

Interpreting success or failure of peanut oral immunotherapy

Peanut oral immunotherapy (OIT) was recently approved by the US FDA. However, not all patients respond to OIT, and there is a high likelihood of regaining sensitization to peanuts after cessation of treatment. It is important, therefore, to identify biomarkers that impact and predict OIT outcomes. In this issue of the JCI, Monian, Tu, and colleagues describe distinct subsets of peanut-reactive CD4⁺ Th cell phenotypes and gene signatures with relevance to OIT outcomes using single-cell RNA-Seq and paired T cell receptor (TCR) α/β sequencing. The insights obtained will inform the development of therapeutics that target these Th cell phenotypes or deplete peanut-specific Th2 cells to achieve sustained nonresponsiveness in food allergy.

Where's the Beef? Understanding Allergic Responses to Red Meat in Alpha-Gal Syndrome

Alpha-gal syndrome (AGS) describes a collection of symptoms associated with IgE-mediated hypersensitivity responses to the glycan galactose-alpha-1,3-galactose (alpha-gal). Individuals with AGS develop delayed hypersensitivity reactions, with symptoms occurring >2 h after consuming mammalian ("red") meat and other mammal-derived food products. The mechanisms of pathogenesis driving this paradigm-breaking food allergy are not fully understood. We review the role of tick bites in the development of alpha-gal-specific IgE and highlight innate and adaptive immune cells possibly involved in alpha-gal sensitization. We discuss the impact of alpha-gal glycosylation on digestion and metabolism of alpha-gal glycolipids and glycoproteins, and the implications for basophil and mast cell activation and mediator release that generate allergic symptoms in AGS.

B cells and food allergy

PURPOSE OF REVIEW

B cells are known in food allergy pathogenesis for their production of IgE but their roles in the development of tolerance to foods are not well understood. Further understanding of B-cell biology in the context of food allergy is essential for the creation of effective prevention strategies and therapies.

RECENT FINDINGS

The majority of allergen-specific IgE in humans appears to arise from antigen-experienced B cells that have already undergone class switch recombination to other antibody isotypes, such as IgG1, and can also be produced by cells class switching to IgE locally in the gastrointestinal tract. Allergen-specific IgG4 can have protective effects in individuals and is associated with tolerance. Regulatory B cells, which can produce allergen-specific IgG4, are reduced in food-allergic individuals and may also be an important component of tolerance. Therapeutic approaches that block the generation and action of IgE and that enhance tolerizing immune responses are being evaluated for the treatment of food allergy.

SUMMARY

B cells play several roles in the development of food allergy versus tolerance. Their functions may translate into the care of food allergy as biomarkers or therapeutic targets and can be employed in other atopic diseases to better understand their pathogenesis and create new avenues for treatment.

Sinomenine Relieves Airway Remodeling By Inhibiting Epithelial-Mesenchymal Transition Through Downregulating TGF-β1 and Smad3 Expression In Vitro and In Vivo

Airway remodeling is associated with dysregulation of epithelial-mesenchymal transition (EMT) in patients with asthma. Sinomenine (Sin) is an effective, biologically active alkaloid that has been reported to suppress airway remodeling in mice with asthma. However, the molecular mechanisms behind this effect remain unclear. We aimed to explore the potential relationship between Sin and EMT in respiratory epithelial cells in vitro and in vivo. First, 16HBE cells were exposed to 100 μg/mL LPS and treated with 200 μg/mL Sin. Cell proliferation, migration, and wound healing assays were performed to evaluate EMT, and EMT-related markers were detected using Western blotting. Mice with OVA-induced asthma were administered 35 mg/kg or 75 mg/kg Sin. Airway inflammation and remodeling detection experiments were performed, and EMT-related factors and proteins in the TGF-β1 pathway were detected using IHC and Western blotting. We found that Sin suppressed cell migration but not proliferation in LPS-exposed 16HBE cells. Sin also inhibited MMP7, MMP9, and vimentin expression in 16HBE cells and respiratory epithelial cells from mice with asthma. Furthermore, it decreased OVA-specific IgE and IL-4 levels in serum, relieved airway remodeling, attenuated subepithelial collagen deposition, and downregulating TGF-β1and Smad3 expression in mice with asthma. Our results suggest that Sin suppresses EMT by inhibiting IL-4 and downregulating TGF-β1 and Smad3 expression.

Natural immunomodulating substances used for alleviating food allergy

Food allergy is a serious health problem affecting more than 10% of the human population worldwide. Medical treatments for food allergy remain limited because immune therapy is risky and costly, and anti-allergic drugs have many harmful side effects and can cause drug dependence. In this paper, we review natural bioactive substances capable of alleviating food allergy. The sources of the anti-allergic substances reviewed include plants, animals, and microbes, and the types of substances include polysaccharides, oligosaccharides, polyphenols, phycocyanin, polyunsaturated fatty acids, flavonoids, terpenoids, quinones, alkaloids, phenylpropanoids, and probiotics. We describe five mechanisms involved in anti-allergic activities, including binding with epitopes located in allergens, affecting the gut microbiota, influencing intestinal epithelial cells, altering antigen presentation and T cell differentiation, and inhibiting the degranulation of effector cells. In the discussion, we present the limitations of existing researches as well as promising advances in the development of anti-allergic foods and/or immunomodulating food ingredients that can effectively prevent or alleviate food allergy. This review provides a reference for further research on anti-allergic materials and their hyposensitizing mechanisms.

Gut Microbiota And Inflammatory Disorders

The gut has been colonized with bacteria, fungi, viruses, archaea, eukarya. The human and bacterial cells are found in a 1:1 ratio, while the variance in the diversity of gut microbiota may result in Dysbiosis. Gut dysbiosis may result in various pathological manifestations. Beneficial gut microbiota may synthesize short-chain fatty acids like acetate, butyrate, propionate, while -gram-negative organisms are the primary source of LPS, a potent pro-inflammatory mediator. Both gut microbiota and microbial products may be involved in immunomodulation as well as inflammation. Prebiotics and probiotics are being explored as therapeutic agents against various inflammatory and autoimmune disorders. Here we discuss the molecular mechanisms involved in gut bacteria-mediated modulation of various inflammatory and autoimmune disorders.

Biology and dynamics of B cells in the context of IgE-mediated food allergy

An increasing number of people suffer from IgE-mediated food allergies. The immunological mechanisms that cause IgE-mediated food allergy have been extensively studied. B cells play a key role in the development of IgE-mediated food allergies through the production of allergen-specific antibodies. While this particular function of B cells has been known for many years, we still do not fully understand the mechanisms that regulate the induction and maintenance of allergen-specific IgE production. It is still not fully understood where in the body IgE class switch recombination of food allergen-specific B cells occurs, and what processes are involved in the immunological memory of allergen-specific IgE responses. B cells can also contribute to the regulation of allergen-specific immune responses through other mechanisms such as antigen presentation and cytokine production. Recent technological advances have enabled highly detailed analysis of small subsets of B cells down to the single-cell level. In this review, we provide an overview of the current knowledge on the biology of B cells in relation to IgE-mediated food allergies.

The association between overweight and prevalence of food allergy in Japanese children: a cross-sectional study

Background

Food allergy (FA) is a common disease in children, and its prevalence has increased in developed countries. The impact of overweight on children health also becomes an important social problem. However, the relationship between overweight and FA is still unclear. We examined the association between overweight and the prevalence of FA among Japanese children.

Methods

We analyzed data obtained using a self-administered questionnaire from 1772 Japanese children. Weight groups according to body mass index cutoff points proposed by the International Obesity Task Force were used to create two groups: overweight and non-overweight. Children were separated into four age groups (3–6 years, 6–9 years, 9–12 years, and 12–15 years) to examine age differences. We performed univariate and multivariate logistic models to examine the association between overweight and FA.

Results

The prevalence of FA was significantly higher in boys (10.6%, p = 0.014) than girls (4.5%) and girls (7.9%, p = 0.012) than boys (2.5%) for 6–9 and 12–15 age groups, respectively. While the prevalence of FA was significantly higher in overweight than non-overweight girls (26.1%, p = 0.005) in the 12–15 age group, no significant difference was found in boys. In girls, overweight was significantly associated with FA after adjustment for age and asthma (odds ratio 1.99, 95% confidence interval 1.01–3.89, p = 0.046).

Conclusions

Our results showed that being overweight was significantly associated with a higher prevalence of FA in girls, but not in boys. Further prospective studies are necessary to find the causal relationship between overweight and FA.

Regulation of oral antigen delivery early in life: Implications for oral tolerance and food allergy

The increasing incidence of food allergy remains a significant public health concern. Food allergy is partially due to a lack, or loss of tolerance to food allergens. Clinical outcomes surrounding early life practices, such as breastfeeding, antibiotic use and food allergen exposure, indicate the first year of life in children represents a unique time for shaping the immune system to reduce allergic outcomes. Animal models have identified distinctive aspects of when and where dietary antigens are delivered within the intestinal tract to promote oral tolerance prior to weaning. Additionally, animal models have identified contributions from maternal proteins from breast milk and bacterial products from the gut microbiota in regulating dietary antigen exposure and promoting oral tolerance, thus connecting decades of clinical observations on the benefits of breastfeeding, early food allergen introduction and antibiotic avoidance in the first year of life in reducing allergic outcomes. Here, we discuss how exposure to gut luminal antigens, including food allergens, is regulated in early life to generate protective tolerance and the implications of this process for preventing and treating food allergies.

Tackling Food Allergy in Infancy

Atopic dermatitis and food allergy are the most common allergic conditions affecting the infant population. Both immunoglobulin E (IgE)-mediated and non-IgE-mediated food allergy are seen in infancy. Early life feeding guidelines have changed dramatically over the past 30 years, more recently because of an improved understanding of IgE-mediated food allergy. This article focuses on identification, diagnosis, management, and prevention of food allergy in the infant population.

T and B Lymphocyte Transcriptional States Differentiate between Sensitized and Unsensitized Individuals in Alpha-Gal Syndrome

The mechanisms of pathogenesis driving alpha-gal syndrome (AGS) are not fully understood. Differences in immune gene expression between AGS individuals and non-allergic controls may illuminate molecular pathways and targets critical for AGS development. We performed immune expression profiling with RNA from the peripheral blood mononuclear cells (PBMCs) of seven controls, 15 AGS participants, and two participants sensitized but not allergic to alpha-gal using the NanoString nCounter PanCancer immune profiling panel, which includes 770 genes from 14 different cell types. The top differentially expressed genes (DEG) between AGS subjects and controls included transcription factors regulating immune gene expression, such as the NFκB pathway (NFKBIA, NFKB2, REL), antigen presentation molecules, type 2/allergic immune responses, itch, and allergic dermatitis. The differential expression of genes linked to T and B cell function was also identified, including transcription factor BCL-6, markers of antigen experience (CD44) and memory (CD27), chemokine receptors (CXCR3, CXCR6), and regulators of B-cell proliferation, cell cycle entry and immunoglobulin production (CD70). The PBMCs from AGS subjects also had increased TNF and IFN-gamma mRNA expression compared to controls. AGS is associated with a distinct gene expression profile in circulating PBMCs. DEGs related to antigen presentation, antigen-experienced T-cells, and type 2 immune responses may promote the development of alpha-gal specific IgE and the maintenance of AGS.

Anti-pig IgE and IgA Antibodies in Naive Primates and Nonhuman Primates With Pig Xenografts

BACKGROUND

Natural preformed anti-pig IgM/IgG antibodies in primates play an important role in xenograft rejection. As it is not clear how IgE and IgA engage in the immune system in xenotransplantation, we investigated natural preformed and elicited anti-pig IgE/IgA in naive primates and after xenotransplantation in nonhuman primates.

METHODS

The binding of IgM/IgG/IgE/IgA antibodies to red blood cells (RBCs) from wild-type (WT), α1,3-galactosyltransferase gene-knockout (GTKO), and GTKO/cytidine monophospho-N-acetylneuraminic acid hydroxylase gene-knockout/β-1,4 N-acetylgalactosaminyltransferase 2 gene-knockout (ie, triple-knockout pigs) pigs were measured by flow cytometry in naive human (n = 50) and baboon (n = 14) sera. Antibody binding to WT and GTKO pig RBCs (pRBCs) was also measured in the sera of baboons (nonsensitized n = 7, sensitized n = 2) and rhesus monkeys (nonsensitized n = 2, sensitized n = 11) following WT or GTKO pig organ/tissue xenotransplantation. Deposition of IgM/IgG/IgE/IgA in the grafts was detected by immunohistochemistry.

RESULTS

The majority of humans had natural preformed IgM/IgG/IgE/IgA to WT and GTKO pRBCs. In contrast, IgM/IgG/IgE/IgA to triple-knockout pRBCs were present at lower levels and frequency (P < 0.01). Baboons also had IgM/IgG/IgE/IgA antibodies against WT pRBCs, but fewer to GTKO and triple-knockout (P < 0.01). After xenotransplantation into nonhuman primates, when IgM/IgG increased, IgE/IgA also increased, but to a lesser extent. In addition to IgM/IgG, IgE or IgA deposition was observed in rejected pig xenografts.

CONCLUSIONS

Primates develop serum anti-pig IgE/IgA antibodies both naturally and during xenograft rejection. The pathophysiological role, if any, of anti-pig IgE/IgA antibodies remains unknown.

IgE-Mediated Fish Allergy in Children

Fish allergy constitutes a severe problem worldwide. Its prevalence has been calculated as high as 7% in paediatric populations, and in many cases, it persists into adulthood with life-threatening signs and symptoms. The following review focuses on the epidemiology of Immunoglobulin E (IgE)-mediated fish allergy, its pathogenesis, clinical manifestations, and a thorough approach to diagnosis and management in the paediatric population. The traditional approach for managing fish allergy is avoidance and rescue medication for accidental exposures. Food avoidance poses many obstacles and is not easily maintained. In the specific case of fish, food is also not the only source of allergens; aerosolisation of fish proteins when cooking is a common source of highly allergenic parvalbumin, and elimination diets cannot prevent these contacts. Novel management approaches based on immunomodulation are a promising strategy for the future of these patients.

Freeman P. Efficacy of Double-Dose Dapsone Combination Therapy in the Treatment of Chronic Lyme Disease/Post-Treatment Lyme Disease Syndrome (PTLDS) and Associated Co-infections: A Report of Three Cases and Retrospective Chart Review

Three patients with multi-year histories of relapsing and remitting Lyme disease and associated co-infections despite extended antibiotic therapy were each given double-dose dapsone combination therapy (DDD CT) for a total of 7-8 weeks. At the completion of therapy, all three patients' major Lyme symptoms remained in remission for a period of 25-30 months. A retrospective chart review of 37 additional patients undergoing DDD CT therapy (40 patients in total) was also performed, which demonstrated tick-borne symptom improvements in 98% of patients, with 45% remaining in remission for 1 year or longer. In conclusion, double-dose dapsone therapy could represent a novel and effective anti-infective strategy in chronic Lyme disease/ post-treatment Lyme disease syndrome (PTLDS), especially in those individuals who have failed regular dose dapsone combination therapy (DDS CT) or standard antibiotic protocols. A randomized, blinded, placebo-controlled trial is warranted to evaluate the efficacy of DDD CT in those individuals with chronic Lyme disease/PTLDS.

Association of Cow's Milk Protein Allergy Prevalence With Socioeconomic Status in a Cohort of Chilean Infants

OBJECTIVES

The aim of the study was to compare the cow's milk protein allergy (CMPA) prevalence in 2 cohorts of children from different socioeconomic strata.

METHODS

Prospective birth cohort that included patients from 2 hospitals providing care for a low- and high-income population, respectively. Healthy newborns ≥34 gestational weeks were recruited and followed up to 12 months by a monthly telephone survey. If ≥2 predefined symptoms/signs suggestive of CMPA were detected, the patient was evaluated by a pediatric gastroenterologist. Diagnosis was confirmed by exclusion diet followed by open oral food challenge.

RESULTS

Overall the prevalence of CMPA was 5.2%, with a 6 times higher prevalence in the high income cohort (9.2%) compared with the low-income group (1.5%; relative risk 6.2; 95% confidence interval 1.8-20.7; P = 0.0005). All the cases were non-immunoglobulin E-mediated with predominantly gastrointestinal symptoms. High-income cohort did have higher frequency of C-section, mother's previous chronic disease, mother's history of atopy/food allergy, older age, and higher educational level of parents. Parent smoking and presence of pets at home were more frequent in the low-income cohort. Multiple logistic regression showed that the high-income cohort did have older age and higher educational level of both parents.

CONCLUSION

In these cohorts the prevalence of CMPA was higher than reported previously in other developing countries and significantly higher in the high-income group. Our findings were associated with sociodemographic characteristics of the parents.

IgE producers in the gut expand the gut's role in food allergy

Details about IgE-producing B cells in the gut in the context of food allergy are scarce, despite the frequent exposure of the gut and its associated lymphoid tissues to dietary antigens. A new study finds that IgE-producing B cells are enriched in gut tissues and are probably generated from local antibody isotype switching.

Immunoglobulin E (IgE)-Mediated Food Allergy in Children: Epidemiology, Pathogenesis, Diagnosis, Prevention, and Management

A food allergy is an immunoglobulin E (IgE)-mediated hypersensitive reaction to food, which consists in the appearance of allergic symptoms; it can vary from common urticaria to even fatal anaphylaxis. The prevalence of food allergies has been increasing in the past twenty years and it represents a major public health problem in industrialized countries. The mechanism that leads to food allergies is the lack of immunologic and clinical tolerance to food allergens. The diagnosis of IgE-mediated food allergies is based on the combined use of a detailed medical history, in-vivo, and in-vitro research of specific IgE, the elimination diet, and the double-blind placebo-controlled food challenge. The only currently available treatment for allergies is the strict elimination diet. This type of attitude, which we could define as “passive”, does not overcome the risk of accidental reactions due to involuntary intake of the culprit food. For food allergy management, an “active” approach is urgently needed, such as specific allergen immunotherapy, which is currently under development and only used for research purposes. This article aims to give an updated review of IgE-mediated food allergies in pediatric populations in terms of epidemiology, pathogenesis, prevention, diagnosis, and management.

Interleukin-13 Is Unlucky for Allergy Sufferers

Anaphylaxis, a life-threatening allergic reaction, is dependent on high affinity allergen-specific IgE. Gowthaman et al. now show that a new interleukin (IL)-13-expressing T helper cell subset specifically promotes high-affinity IgE responses. The discovery of T follicular helper (Tfh)13 cells defines potential new targets for allergy therapies.

Case series of sebelipase alfa hypersensitivity reactions and successful sebelipase alfa rapid desensitization

Allergic immune-mediated hypersensitivity reactions are known potential complications of enzyme replacement therapy. Sebelipase alfa, recombinant lysosomal acid lipase (LAL), is a potentially life-altering treatment for patients with LAL deficiency. There is very little information on the diagnosis and management of immediate hypersensitivity reactions to this drug. Here we present three unique cases of hypersensitivity reactions to sebelipase alfa, spanning a broad age spectrum from infancy to adulthood, each managed with successful rapid desensitization.

Combined Exposure of Activated Intestinal Epithelial Cells to Nondigestible Oligosaccharides and CpG-ODN Suppresses Th2-Associated CCL22 Release While Enhancing Galectin-9, TGFβ, and Th1 Polarization

Background

Short-chain galacto- and long-chain fructo-oligosaccharides (scGOS/lcFOS) and CpG-ODN affect intestinal epithelial cells (IEC). Epithelial IL1α may contribute to allergic sensitization via autocrine mediator release affecting dendritic cells (DC). We studied whether IL1α contributes to Th2-associated mediator release by activated IEC and IEC/DC cocultures and possible modulation by scGOS/lcFOS±CpG-ODN.

Methods

Solid phase or transwell cultured IEC were preincubated with IL1α and/or IFNγ/TNFα for 6 h. The transwell IEC were also apically exposed to scGOS/lcFOS±CpG-ODN for 6 h, washed, and re-exposed, while cocultured with immature moDC (ccDC) for 48 h. These ccDC were subsequently added to allogeneic naïve T cells (MLR). IEC- and/or DC-derived mediators and T cell cytokines were measured.

Results

IL1α tended to enhance IL25 and enhanced IL33 and CCL20 release by IEC, while IL1α or TNFα or IFNγ enhanced CCL22. These were all further increased upon combined exposure of IFNγ/TNFα±IL1α coinciding with increased IL33 secretion in the solid phase culture. In the transwell, IL25 and IL33 remained under detection, while CCL20 and CCL22 were induced by IL1α or IFNγ/TNFα, respectively, and a synergistic increase was observed upon combined exposure of IFNγ/TNFα and IL1α. Furthermore, IFNγ was found to enhance galectin-9 secretion, which was more pronounced in IFNγ/TNFα±IL1α-exposed IEC and coincided with TGFβ increase. Epithelial CpG-ODN exposure further increased CCL20, while reducing CCL22 release by IFNγ/TNFα/IL1α-activated IEC; however, scGOS/lcFOS suppressed both. Combined scGOS/lcFOS and CpG-ODN reduced CCL22, while CCL20 and regulatory galectin-9 and TGFβ remained high in the supernatant of IFNγ/TNFα/IL1α-activated IEC and the following IEC/DC coculture. ccDC of scGOS/lcFOS- and CpG-ODN-exposed IFNγ/TNFα/IL1α-activated IEC increased IFNγ, IL10, TGFβ, and galectin-9 secretion in the MLR compared to ccDC exposed to control-activated IEC.

Conclusion

IL1α enhanced CCL20 and Th2-associated CCL22 release by IFNγ/TNFα-activated IEC. Combined scGOS/lcFOS and CpG-ODN exposure suppressed CCL22, while maintaining high CCL20, TGFβ, and galectin-9 concentrations. In addition, ccDC derived from this IEC/DC coculture enhanced Th1 and regulatory mediator secretion mimicking known in vivo effects.

Designer covalent heterobivalent inhibitors prevent IgE-dependent responses to peanut allergen

Allergies are a result of allergen proteins cross-linking allergen-specific IgE (sIgE) on the surface of mast cells and basophils. The diversity and complexity of allergen epitopes, and high-affinity of the sIgE-allergen interaction have impaired the development of allergen-specific inhibitors of allergic responses. This study presents a design of food allergen-specific sIgE inhibitors named covalent heterobivalent inhibitors (cHBIs) that selectively form covalent bonds to only sIgEs, thereby permanently inhibiting them. Using screening reagents termed nanoallergens, we identified two immunodominant epitopes in peanuts that were common in a population of 16 allergic patients. Two cHBIs designed to inhibit only these two epitopes completely abrogated the allergic response in 14 of the 16 patients in an in vitro assay and inhibited basophil activation in an allergic patient ex vivo analysis. The efficacy of the cHBI design has valuable clinical implications for many allergen-specific responses and more broadly for any antibody-based disease.

The Microbiome and Food Allergy

The gut-associated lymphoid tissue (GALT) faces a considerable challenge. It encounters antigens derived from an estimated 1014 commensal microbes and greater than 30 kg of food proteins yearly. It must distinguish these harmless antigens from potential pathogens and mount the appropriate host immune response. Local and systemic hyporesponsiveness to dietary antigens, classically referred to as oral tolerance, comprises a distinct complement of adaptive cellular and humoral immune responses. It is increasingly evident that a functional epithelial barrier engaged in intimate interplay with innate immune cells and the resident microbiota is critical to establishing and maintaining oral tolerance. Moreover, innate immune cells serve as a bridge between the microbiota, epithelium, and the adaptive immune system, parlaying tonic microbial stimulation into signals critical for mucosal homeostasis. Dysregulation of gut homeostasis and the subsequent disruption of tolerance therefore have clinically significant consequences for the development of food allergy.

Healthy infants harbor intestinal bacteria that protect against food allergy

There has been a striking generational increase in life-threatening food allergies in Westernized societies^1,2 One hypothesis to explain this rising prevalence is that 21^st century lifestyle practices, including misuse of antibiotics, dietary changes, and higher rates of Caesarean birth and formula feeding have altered intestinal bacterial communities; early life alterations may be particularly detrimental.^3,4 To better understand how commensal bacteria regulate food allergy in humans we colonized germ free (GF) mice with feces from healthy or cow’s milk allergic (CMA) infants ⁵. We show here that GF mice colonized with bacteria from healthy, but not CMA, infants were protected against anaphylactic responses to a cow’s milk allergen. Differences in bacterial composition separated the healthy and CMA populations in both the human donors and the colonized mice. Healthy and CMA colonized mice also exhibited unique transciptome signatures in the ileal epithelium. Correlation of ileal bacteria with genes upregulated in the ileum of healthy or CMA colonized mice identified a Clostridial species, Anaerostipes caccae, that protected against an allergic response to food. Our findings demonstrate that intestinal bacteria are critical for regulating allergic responses to dietary antigens and suggest that interventions that modulate bacterial communities may be therapeutically relevant for food allergy.

Genetic diversity between mouse strains allows identification of the CC027/GeniUnc strain as an orally reactive model of peanut allergy

BACKGROUND

Improved animal models are needed to understand the genetic and environmental factors that contribute to food allergy.

OBJECTIVE

We sought to assess food allergy phenotypes in a genetically diverse collection of mice.

METHODS

We selected 16 Collaborative Cross (CC) mouse strains, as well as the classic inbred C57BL/6J, C3H/HeJ, and BALB/cJ strains, for screening. Female mice were sensitized to peanut intragastrically with or without cholera toxin and then challenged with peanut by means of oral gavage or intraperitoneal injection and assessed for anaphylaxis. Peanut-specific immunoglobulins, T-cell cytokines, regulatory T cells, mast cells, and basophils were quantified.

RESULTS

Eleven of the 16 CC strains had allergic reactions to intraperitoneal peanut challenge, whereas only CC027/GeniUnc mice reproducibly experienced severe symptoms after oral food challenge (OFC). CC027/GeniUnc, C3H/HeJ, and C57BL/6J mice all mounted a T_H2 response against peanut, leading to production of IL-4 and IgE, but only the CC027/GeniUnc mice reacted to OFC. Orally induced anaphylaxis in CC027/GeniUnc mice was correlated with serum levels of Ara h 2 in circulation but not with allergen-specific IgE or mucosal mast cell protease 1 levels, indicating systemic allergen absorption is important for anaphylaxis through the gastrointestinal tract. Furthermore, CC027/GeniUnc, but not C3H/HeJ or BALB/cJ, mice can be sensitized in the absence of cholera toxin and react on OFC to peanut.

CONCLUSIONS

We have identified and characterized CC027/GeniUnc mice as a strain that is genetically susceptible to peanut allergy and prone to severe reactions after OFC. More broadly, these findings demonstrate the untapped potential of the CC population in developing novel models for allergy research.

Neuro-immune interactions in allergic diseases: novel targets for therapeutics

Recent studies have highlighted an emerging role for neuro-immune interactions in mediating allergic diseases. Allergies are caused by an overactive immune response to a foreign antigen. The peripheral sensory and autonomic nervous system densely innervates mucosal barrier tissues including the skin, respiratory tract and gastrointestinal (GI) tract that are exposed to allergens. It is increasingly clear that neurons actively communicate with and regulate the function of mast cells, dendritic cells, eosinophils, Th2 cells and type 2 innate lymphoid cells in allergic inflammation. Several mechanisms of cross-talk between the two systems have been uncovered, with potential anatomical specificity. Immune cells release inflammatory mediators including histamine, cytokines or neurotrophins that directly activate sensory neurons to mediate itch in the skin, cough/sneezing and bronchoconstriction in the respiratory tract and motility in the GI tract. Upon activation, these peripheral neurons release neurotransmitters and neuropeptides that directly act on immune cells to modulate their function. Somatosensory and visceral afferent neurons release neuropeptides including calcitonin gene-related peptide, substance P and vasoactive intestinal peptide, which can act on type 2 immune cells to drive allergic inflammation. Autonomic neurons release neurotransmitters including acetylcholine and noradrenaline that signal to both innate and adaptive immune cells. Neuro-immune signaling may play a central role in the physiopathology of allergic diseases including atopic dermatitis, asthma and food allergies. Therefore, getting a better understanding of these cellular and molecular neuro-immune interactions could lead to novel therapeutic approaches to treat allergic diseases.

Post-transplantation Development of Food Allergies

PURPOSE OF REVIEW

The development of food allergies is increasingly being recognized as a post-solid organ transplant complication. In this article, we review the spectrum of post-transplant food allergy development and the proposed mechanisms for de novo food allergies and the clinical significance they pose.

RECENT FINDINGS

The development of new food allergies is disproportionately associated with pediatric liver transplants, where it occurs in up to 38% of select populations. The mechanism of food allergy development is not completely understood; however, it is likely promoted by unbalanced immune suppression. De novo food allergy development is a common complication of solid organ transplants with the highest risk occurring in pediatric liver transplant recipients. There are likely multiple mechanisms for food allergy development including passive transfer of membrane-bound IgE and lymphocytes from donor to recipient, as well as loss of food tolerance and active development of new food allergies. The optimal management of food allergies following organ transplants has not been well researched but may include changing the immune suppression regimen if the food allergy does not resolve without intervention.

A Mouse Model of Peanut Allergy Induced by Sensitization Through the Gastrointestinal Tract

Animal models of disease enable the study of the pathology, biomarkers, and treatments for the disease being studied. These models become particularly useful in the study of diseases, such as peanut allergy, that currently have no FDA-approved therapy options. Here, we describe a mouse model of peanut allergy using a peanut extract and cholera toxin that can be applied to both BALB/c and C3H/HeJ mouse strains. Sensitization is induced through the gastrointestinal tract resulting in elevated levels of peanut-specific IgE and anaphylaxis upon challenge with peanut proteins. This model has been used to study the cells and molecules involved in the development of peanut allergy and to evaluate novel immunotherapy approaches and the underlying mechanisms of immunotherapy. Potential utilities of this model are numerous and may include studies on microbial influences on peanut allergy and discovery of biomarkers of anaphylaxis.

Comparing immediate-type food allergy in humans and companion animals-revealing unmet needs

Adverse food reactions occur in human as well as veterinary patients. Systematic comparison may lead to improved recommendations for prevention and treatment in both. In this position paper, we summarize the current knowledge on immediate-type food allergy vs other food adverse reactions in companion animals, and compare this to the human situation. While the prevalence of food allergy in humans has been well studied for some allergens, this remains to be investigated for animal patients, where owner-reported as well as veterinarian-diagnosed food adverse reactions are on the increase. The characteristics of the disease in humans vs dogs, cats, and horses are most often caused by similar, but sometimes species-dependent different pathophysiological mechanisms, prompting the specific clinical symptoms, diagnoses, and treatments. Furthermore, little is known about the allergen molecules causative for type I food allergy in animals, which, like in human patients, could represent predictive biomarkers for risk evaluation. The definite diagnosis of food allergy relies-as in humans-on elimination diet and provocation tests. Besides allergen avoidance in daily practice, novel treatment options and tolerization strategies are underway. Taken together, numerous knowledge gaps were identified in veterinary food allergy, which need to be filled by systematic comparative studies.