Heat processing of peanut seed enhances the sensitization potential of the major peanut allergen Ara h 6.

Scope: Processing of food has been shown to impact IgE binding and functionality of food allergens. In the present study, we investigated the impact of heat processing on the sensitization capacity of Ara h 6, a major peanut allergen and one of the most potent elicitors of the allergic reaction.

Methods And Results: Peanut extracts obtained from raw or heat-processed peanut and some fractions thereof were biochemically and immunochemically characterized.

Allergenicity of peanut component Ara h 2: Contribution of conformational versus linear hydroxyproline-containing epitopes.

Background: The 2S-albumin Ara h 2 is the most potent peanut allergen and a good predictor of clinical reactivity in allergic children. Posttranslational hydroxylation of proline residues occurs in DPYSP(OH)S motifs, which are repeated 2 or 3 times in different isoforms.

Objectives: We investigated the effect of proline hydroxylation on IgE binding and the relative contributions of linear and conformational epitopes to Ara h 2 allergenicity.

Specificity of IgE antibodies from patients allergic to goat's milk and tolerant to cow's milk determined with plasmin-derived peptides of bovine and caprine β-caseins.

Scope: Despite a sequence homology of 90% between bovine and caprine β-caseins (CN), IgE antibodies from patients allergic to goat's milk (GM), but tolerant to cow's milk (CM), recognize caprine β-CN without cross-reacting with bovine β-CN. We investigated this lack of cross-reactivity by evaluating the IgE-reactivity toward peptides isolated from plasmin hydolysates of bovine and caprine β-CN.

Methods And Results: The IgE-binding capacity of plasmin-derived peptides was evaluated with sera from 10 CM-allergic patients and 12 GM-allergic/CM-tolerant patients.

Trypsin resistance of the major peanut allergen Ara h 6 and allergenicity of the digestion products are abolished after selective disruption of disulfide bonds.

Scope: 2S-albumins Ara h 2 and Ara h 6 are the most widely recognized and potent allergens for peanut-allergic patients. These allergens are particularly resistant to proteolysis and the digestion products generally retain significant allergenicity. Five disulfide bridges (DB) stabilize Ara h 6 overall structure and their influence on the trypsin resistance and on the allergenicity of the digestion products was investigated.

Immunological and metabolomic impacts of administration of Cry1Ab protein and MON 810 maize in mouse.

We have investigated the immunological and metabolomic impacts of Cry1Ab administration to mice, either as a purified protein or as the Cry1Ab-expressing genetically modified (GM) MON810 maize. Humoral and cellular specific immune responses induced in BALB/cJ mice after intra-gastric (i.g.

Immunochemical characterisation of structure and allergenicity of peanut 2S albumins using different formats of immunoassays.

Proteins of the 2S albumin family, such as Ara h2 and Ara h6, are most frequently involved in peanut allergy. We have developed a reverse enzyme allergo-sorbent test (EAST) in which total serum IgE antibodies are first captured by immobilised anti-human IgE monoclonal antibodies, and then the binding of the anti-Ara h2 and anti-Ara h6 specific IgE to the corresponding labelled allergens is measured. This reverse immunoassay was used either as a direct EAST or as an EAST inhibition assay to study the interactions of whole peanut protein extract and purified Ara h2 and Ara h6 with IgE antibodies from peanut-allergic patients.

Enzyme immunoassay for a urinary metabolite of 4-hydroxynonenal as a marker of lipid peroxidation.

Free radical reactions are involved in the pathogenesis of numerous diseases, so there is a real need to develop biomarkers that reflect these reactions in vivo. 4-Hydroxy-2-nonenal (HNE) is a major product of the lipid peroxidation process that is a consequence of free radical reactions. We present here the development and validation of an enzyme immunoassay (EIA) of the major urinary metabolite of HNE, namely 1,4-dihydroxynonane-mercapturic acid (DHN-MA).