Novel post-translationally cleaved Ara h 2 proteoforms: Purification, characterization and IgE-binding properties.

The 2S albumins Ara h 2 and Ara h 6 have been shown to be the most important source of allergenicity in peanut. Several isoforms of these allergens have been described. Using extraction and liquid chromatography we isolated proteins with homology to Ara h 2 and characterized hitherto unknown Ara h 2 proteoforms with additional post-translational cleavage.

Dose and route of administration determine the efficacy of prophylactic immunotherapy for peanut allergy in a Brown Norway rat model.

Introduction: Allergen-specific immunotherapy (IT) is emerging as a viable option for treatment of peanut allergy. Yet, prophylactic IT remains unexplored despite early introduction of peanut in infancy was shown to prevent allergy. There is a need to understand how allergens interact with the immune system depending on the route of administration, and how different dosages of allergen may protect from sensitisation and a clinical active allergy.

Determination of Allergen Levels, Isoforms, and Their Hydroxyproline Modifications Among Peanut Genotypes by Mass Spectrometry.

The recently published reference genome of peanuts enables a detailed molecular description of the allergenic proteins of the seed. We used LC-MS/MS to investigate peanuts of different genotypes to assess variability and to better describe naturally occurring allergens and isoforms. Using relative quantification by mass spectrometry, minor variation of some allergenic proteins was observed, but total levels of Ara h 1, 2, 3, and 6 were relatively consistent among 20 genotypes.

Peanut cross-contamination in randomly selected baked goods.

Background: The current standard of care for managing peanut allergy includes avoidance of peanut and use of injectable epinephrine; however, strict avoidance is difficult and accidental ingestion is common with potentially serious consequences. Despite vigilance and efforts to minimize the risk of accidental exposure, peanut protein cross-contamination continues to occur in a variety of foods, including baked goods.

Objective: To assess and quantify the presence of peanut protein contamination in certain baked goods.

Purification and Initial Characterization of Ara h 7, a Peanut Allergen from the 2S Albumin Protein Family.

2S albumins are important peanut allergens. Within this protein family, Ara h 2 and Ara h 6 have been described in detail, but Ara h 7 has received little attention. We now describe the first purification of Ara h 7 and its characterization.

Development of a Sandwich Enzyme-Linked Immunosorbent Assay for Detection and Quantification of Clam Residues in Food Products.

Seafood is a frequent cause of allergic reactions to food globally. The presence of undeclared trace amounts of clam can cause allergic reactions in sensitive individuals. Limited tools are available to test food products for the presence of traces of clam.

The importance of the 2S albumins for allergenicity and cross-reactivity of peanuts, tree nuts, and sesame seeds.

Allergies to peanuts, tree nuts, and sesame seeds are among the most important food-related causes of anaphylaxis. Important clinical questions include: Why is there a variable occurrence of coallergy among these foods and Is this immunologically mediated? The clinical and immunologic data summarized here suggest an immunologic basis for these coallergies that is based on similarities among the 2S albumins. Data from component resolved diagnostics have highlighted the relationship between IgE binding to these allergens and the presence of IgE-mediated food allergy.

Risk of shared equipment in restaurants for consumers with peanut allergy: a simulation for preparing Asian foods: A simulation for preparing Asian foods.

Background: Allergic reactions to meals consumed outside the home are common and can be severe and sometimes fatal.

Objective: To quantify the risk reduction potentially achieved by increasing an individual's threshold sensitivity to peanut (such as by means of immunotherapy) in scenarios of peanut exposure through shared kitchen materials in a restaurant setting.

Methods: Three versions of popular peanut-containing sauces were selected to represent common ingredients used in Asian cooking.

Effect of heat treatment on the conformational stability of intact and cleaved forms ofthe peanut allergen Ara h 6 in relation to its IgE-binding potency.

This work reports on theeffect of heat treatment on the protein conformational stabilityof intact and post-translationallycleaved peanut allergen Ara h 6 in relation to IgE-binding. Intact and post-translationallycleaved Ara h 6 are structurally similar and theirstrong resistance to denaturant-inducedunfolding is comparable. Only upon exposure toautoclave conditions the twoforms of Ara h 6 demonstrated susceptibility toirreversible denaturationresulting in a significant decrease in IgE-binding potency.

Estimated risk reduction to packaged food reactions by epicutaneous immunotherapy (EPIT) for peanut allergy.

Background: Peanut allergy is a generally persistent, sometimes life-threatening food allergy. With no treatments demonstrating the ability to cure a food allergy, the focus of drugs in development has been on providing a level of protection against accidental exposure reactions. However, no study has estimated the relative risk reduction of a food-allergic population receiving a specific immunotherapeutic treatment for their allergies.

Comparison of recovery and immunochemical detection of peanut proteins from differentially roasted peanut flour using ELISA.

The effect of heat on extractability and immunoreactivity of proteins from roasted peanut flours and whole peanuts was evaluated using two general protein assays and six commercial peanut ELISA kits, respectively. The highest amount of protein was recovered from roasted peanuts with all ELISAs, while recovery showed a decrease with increasing levels of roasting of the peanut flours. Only the Morinaga kit showed sufficient sensitivity to detect peanut at low concentrations of the dark roast peanut flours.

Chemically modified peanut extract shows increased safety while maintaining immunogenicity.

Background: Peanuts are most responsible for food-induced anaphylaxis in adults in developed countries. An effective and safe immunotherapy is urgently needed. The aim of this study was to investigate the immunogenicity, allergenicity, and immunotherapeutic efficacy of a well-characterized chemically modified peanut extract (MPE) adsorbed to Al(OH) .

Purification and Characterization of Naturally Occurring Post-Translationally Cleaved Ara h 6, an Allergen That Contributes Substantially to the Allergenic Potency of Peanut.

The 2S albumin Ara h 6 is one of the most important peanut allergens. A post-translationally cleaved Ara h 6 (pAra h 6) was purified from Virginia type peanuts, and the cleavage site was mapped using high-resolution mass spectrometry. Compared to intact Ara h 6, pAra h 6 lacks a 5-amino acid stretch, resembling amino acids 43-47 (UniProt accession number Q647G9) in the nonstructured loop.

Release of Major Peanut Allergens from Their Matrix under Various pH and Simulated Saliva Conditions-Ara h2 and Ara h6 Are Readily Bio-Accessible.

The oral mucosa is the first immune tissue that encounters allergens upon ingestion of food. We hypothesized that the bio-accessibility of allergens at this stage may be a key determinant for sensitization. Light roasted peanut flour was suspended at various pH in buffers mimicking saliva.

Quantitative risk reduction through peanut immunotherapy: Safety benefits of an increased threshold in Europe.

Background: The clinical relevance of increasing an allergic individual's peanut sensitivity threshold by immunotherapy, that is, eliciting dose (ED) to 300 or 1000 mg peanut protein, has not been previously characterized in a European population. In this study, we quantify the clinical benefits of an increased threshold of reaction following immunotherapy for the peanut-allergic individual.

Methods: Quantitative risk assessments incorporated numerous inputs to predict the risk of an allergic reaction after exposure to residual peanut protein in packaged foods.

Quantitative Assessment of the Safety Benefits Associated with Increasing Clinical Peanut Thresholds Through Immunotherapy.

Background: Peanut immunotherapy studies are conducted with the aim to decrease the sensitivity of patients to peanut exposure with the outcome evaluated by testing the threshold for allergic response in a double-blind placebo-controlled food challenge. The clinical relevance of increasing this threshold is not well characterized.

Objective: We aimed to quantify the clinical benefit of an increased threshold for peanut-allergic patients.

Endurance Exercise Increases Intestinal Uptake of the Peanut Allergen Ara h 6 after Peanut Consumption in Humans.

Controlled studies on the effect of exercise on intestinal uptake of protein are scarce and underlying mechanisms largely unclear. We studied the uptake of the major allergen Ara h 6 following peanut consumption in an exercise model and compared this with changes in markers of intestinal permeability and integrity. Ten overnight-fasted healthy non-allergic men ( = 4) and women ( = 6) (23 ± 4 years) ingested 100 g of peanuts together with a lactulose/rhamnose (L/R) solution, followed by rest or by 60 min cycling at 70% of their maximal workload.

Detection of peanut allergen in human blood after consumption of peanuts is skewed by endogenous immunoglobulins.

Some studies have suggested that allergens may appear in the circulation after ingestion of allergenic food sources. The reported levels of allergen in serum, however, are low, and conclusions between studies differ. Here, we investigated factors that determine the detection of allergens in serum after consumption of peanuts.