Assessing allergen levels in peach and nectarine cultivars. Ann Allergy Asthma Immunol
ABSTRACT The lipid transfer protein Pru p 3 has been identified as a major peach fruit allergen. However, the putative peach member of the Bet v 1 family, Pru p 1, has been neither identified nor characterized.
To determine the distribution and solubility properties of the main peach allergens and to quantify Pru p 3 and Pru p 1 levels in peach and nectarine cultivars.
Peach peel and pulp were extracted using different buffers, and extracts were analyzed by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunodetection using polyclonal antibodies against lipid transfer proteins, profilins, and Bet v 1 homologues. Pru p 3 was quantified in peach and nectarine cultivars using a sandwich enzyme-linked immunosorbent assay method. A similar method was developed to quantify Pru p 1.
A differential distribution between peel and pulp and different solubility properties were found for Pru p 3, Pru p 1, and peach profilin. Mean Pru p 3 levels were 132.86, 0.61, and 16.92 microg/g of fresh weight of peels, pulps, and whole fruits, respectively. The corresponding mean Pru p 1 levels were 0.62, 0.26, and 0.09 microg/g of fresh weight. Most US cultivars showed higher levels of both allergens than Spanish cultivars.
The different distribution and solubility properties of the main peach allergens can determine the quality of fruit extracts used as diagnostic tools. These differences, together with the natural variation of Pru p 3 and Pru p 1 levels among peach and nectarine cultivars, can be exploited to reduce peach allergenicity by means of industrial processing and plant breeding.
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- "Comparisons of food allergen concentrations across different cultivars of a crop have rarely been attempted because protein thresholds for eliciting an allergic reaction have typically not been determined and vary by individual (Blindslev-Jensen et al., 2002). However, where endogenous allergen concentrations have been characterized across crop cultivars, they have been found to vary considerably (Ahrazem et al., 2007; Ariyarathna et al., 2009; Houston et al., 2011; Kuppannan et al., 2010; Salekdeh and Komatsu, 2007; Zuidmeer et al., 2006). In addition to differences among cultivars, natural variability in allergen concentrations can occur in response to differing environmental conditions, harvest timing, or storage conditions (Doerrer et al., 2010; Sancho et al., 2006a,b). "
ABSTRACT: The safety assessment for transgenic food crops currently includes an evaluation of the endogenous allergy potential (via serum IgE screening) when the non-transgenic counterpart is a commonly allergenic food. The value of this analysis in the safety assessment of transgenic crops, especially with reference to recent requests to quantify individual allergen concentrations in raw commodities, is examined. We conclude that the likelihood of upregulating an endogenous allergen due to transgenesis is no greater than from traditional breeding which has a history of safety and is largely unregulated. The potential consequences of upregulating an endogenous allergen are also unclear.Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 07/2011; 49(10):2667-9. DOI:10.1016/j.fct.2011.07.018 · 2.61 Impact Factor
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- "Moreover, the use of fresh foods shows low reproducibility problems due to variations in the allergenic content of the different species . Nowadays, double-blind, placebo-controlled food challenge (DBPCFC) is considered the gold standard, although it does not discriminate between food allergy and non-immune-mediated food hypersensitivity . "
ABSTRACT: In intestinal food allergy, the non-specificity of gastrointestinal symptoms and the limited access to the reacting organ are the reasons for the limited understanding of the pathophysiology of this disease and the difficulties in establishing an appropriate diagnosis in the individual patient. To develop an in vitro model reproducing pathophysiological mechanisms of IgE mediated food allergy. Distal duodenum biopsies of nine patients with food allergy and 10 control subjects were cultured for 3 h with medium alone and with 1 mg/ml of peptic-tryptic digest of wheat gliadin, wheat albumins, and apple proteins. Each biopsy was used for conventional histological examination and for immunohistochemical detection of IgE-positive cells. We have also analyzed the expression of tight junction proteins, occludin, claudin-1, and ZO-1 by immunoconfocal microscopy. Histamine and tryptase release were measured in the culture medium and collected at 0, 30 min, and 3 h of culture using an enzyme and radio immunoassay, respectively. Exposure of small intestinal biopsy specimens of patients with food allergy to food allergens led to a significative increase of IgE-positive cells with a significative increase of histamine and tryptase release and an altered expression of tight junction proteins. No differences were found in intestinal biopsies of controls, cultured with or without food antigens. Small intestinal organ culture is a functional model of food allergy and could be considered as an in vitro oral food challenge, with evident reduction of costs and risks for the patients.Scandinavian Journal of Gastroenterology 10/2010; 46(2):177-87. DOI:10.3109/00365521.2010.525716 · 2.33 Impact Factor
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- "Pru p 1.01 is known to be a major peach allergen (Ahrazem et al., 2007) and was previously found in large amount in bark, xylem, and root of peach tree Figure 4 "
ABSTRACT: PR-10 proteins are a family of pathogenesis-related (PR) allergenic proteins playing multifunctional roles. The peach (Prunus persica) major allergen, Pru p 1.01, and its isoform, Pru p 1.06D, were found highly expressed in the fruit skin at the pit hardening stage, when fruits transiently lose their susceptibility to the fungal pathogen Monilinia spp. To investigate the possible role of the two Pru p 1 isoforms in plant defense, the recombinant proteins were expressed in Escherichia coli and purified. Light scattering experiments and circular dichroism spectroscopy showed that both proteins are monomers in solution with secondary structures typical of PR-10 proteins. Even though the proteins do not display direct antimicrobial activity, they both act as RNases, a function possibly related to defense. The RNase activity is different for the two proteins, and only that of Pru p 1.01 is affected in the presence of the cytokinin zeatin, suggesting a physiological correlation between Pru p 1.01 ligand binding and enzymatic activity. The binding of zeatin to Pru p 1.01 was evaluated using isothermal titration calorimetry, which provided information on the stoichiometry and on the thermodynamic parameters of the interaction. The structural architecture of Pru p 1.01 and Pru p 1.06D was obtained by homology modeling, and the differences in the binding pockets, possibly accounting for the observed difference in binding activity, were evaluated.Plant physiology 06/2009; 150(3):1235-47. DOI:10.1104/pp.109.139543 · 7.39 Impact Factor