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Scope: Currently there are no specific recommendations for the use of any particular infant formula in the prevention of cow's milk allergy (CMA). Recently, there has been an increasing interest in alternative infant formulas based on milk proteins from other sources than the cow, including milk from other mammalians such as goat, sheep, donkey, horse, and camel. Whereas these have been studied for their usability in CMA management, there are no studies of their CMA preventive capacity. Thus, the aim of this study is to evaluate whether camel milk can prevent CMA and vice versa., Methods and Results: The capacity of camel milk in preventing CMA and vice versa is evaluated in a well-established prophylactic Brown Norway rat model. IgG1, IgE, and IgA responses, allergy elicitation, intestinal and mLN gene expression, and protein uptake are analyzed. The study demonstrates that camel and cow's milk in general has an insignificant cross-preventive capacity. Yet, whereas cow's milk is shown to have a low transient capacity to prevent sensitization and clinically active camel milk allergy, camel milk does not show this effect for CMA., Conclusions: This study suggests that due to lack of cross-tolerance camel milk cannot be used for CMA prevention., (© 2022 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH GmbH.)

Scope: The aim of this work was to investigate the effects of high-intensity ultrasound (sonication), on the structure and allergenicity of the major cow's milk allergen, beta-lactoglobulin (BLG)., Methods and Results: Structural changes upon sonication of BLG were monitored by circular dichroism spectroscopy, tryptophan emission fluorescence, hydrophobic dye and retinol binding, as well as digestibility and phenol-oxidase cross-linking capacity. Allergenicity was monitored in individual patients' sera, basophil activation test, and skin prick testing in 41 cow's milk allergy patients. Uncontrolled local temperature changes induced modifications in BLG secondary structure accompanied by formation of dimers, trimers, and oligomers of BLG that were more digestible by pepsin and had reduced retinol binding. Controlled temperature conditions induced changes in secondary structure of BLG without causing formation of oligomers, or changing protein's capacity to bind retinol. Both sonicated forms of BLG had more exposed hydrophobic surfaces than native BLG and underwent facilitated cross-linking reaction with phenol-oxidase. Sonication had a minor effect on IgE-binding properties of BLG., Conclusion: Sonication-induced structural changes in major whey allergen were not clinically significant in cow's milk allergy patients. Ultrasound can be a safe procedure for dairy processing as it maintains the nutritional value and does not increase allergenic potential of BLG., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Scope: Four Bet v 1 homologous food allergens from celeriac (rApi g 1), apple (rMal d 1), peach (rPru p 1) and hazelnut (rCor a 1), were used to probe the structural responsiveness of the Bet v 1 scaffold to gastric digestion conditions and its impact on allergenicity., Methods and Results: Low pH induced conformational changes of all homologues, which was reduced at physiological ionic strength for all except rPru p 1 as observed by circular dichroism (CD)-spectroscopy. The homologues were rapidly digested by pepsin, losing their IgE binding activity, although the kinetics and patterns of digestion varied subtly between homologues, rApi g 1 being the most stable. We have demonstrated for the first time that gastric phosphatidyl-choline (PC) induced conformational changes in all homologues but only rMal d 1 penetrated the PC vesicles as detected by fluorescence polarization, slowing its digestion and retaining more of its allergenic activity. PC enhanced basophil activation of all digested allergens except rApi g 1., Conclusion: The Bet v 1 scaffold is generally susceptible to low pH and pepsinolysis and interacts with PC vesicles, properties which can explain effects of the gastric environment on their allergenicity. These data show the importance of including surfactants in model digestion systems., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

White lupin is considered to be a rich source of protein with a notable content of lysine and is being increasingly used in bakery, confectionery, snacks and pastry products due to its multifunctional properties, in addition to its potential hypocholesterolemic and hypoglycemic properties. However, lupin seed flour has been reported as a causative agent of allergic reactions, especially in patients with allergy to peanut since the risk of immunological cross-reactivity between lupin and peanut is higher than with other legumes. Previously, we had identified two proteins as major lupin allergens (34.5 and 20 kDa) as determined by IgE immunoblotting using sera of 23 patients with lupin-specific IgE. The aim of this study was to purify and characterize the two major lupin allergens. The results using in vitro IgE-binding studies and MS analysis have shown that the 34.5 kDa allergen (Lup-1) is a conglutin β (vicilin-like protein) while the 20 kDa allergen (Lup-2) corresponds to the conglutin α fraction (legumin-like protein). The high level of amino acid sequence homology of Lup-1 and Lup-2 with the major allergens of some legumes explains the IgE cross-reactivity and clinical cross-reactivity of lupin and other legumes.

This article reviews recent studies that address one of the major unanswered questions in food allergy research: what attributes of food or food proteins contribute to or enhance food allergenicity?

A lipid transfer protein (LTP, Cor a 8) together with the 11S (Cor a 9) and 7S seed storage globulins (Cor a 11) are major food allergens present in hazelnut. Methods are described for their purification and characterisation using in-gel tryptic digestion mass spectrometry to confirm their identities and circular dichroism and Fourier-transform infrared spectroscopies to demonstrate that they are authentically folded. Preliminary immunochemical studies have also confirmed that the purified preparations retain their immunological properties in terms of immunoglobulin E binding, determined by immunoblotting using serum from hazelnut allergic patients. These preparations form a basis for development of improved methods of diagnosis of food allergy based on the concept of component-resolved diagnosis.

Pru p 1 (a Bet v 1 homologue) and Pru p 3 (a nonspecific lipid transfer protein; nsLTP) are major allergenic proteins in peach fruit, but differ in their abundance and stability. Pru p 1 has low abundance and is highly labile and was purified after expression as a recombinant protein in Escherichia coli. Pru p 3 is highly abundant in peach peel and was purified by conventional methods. The identities of the proteins were confirmed by sequence analysis and their masses determined by MS analysis. The purified proteins reacted with antisera against related allergens from other species: Pru p 1 with antiserum to Bet v 1 and Pru p 3 with antiserum to Mal d 3 (from apple). The presence of secondary and tertiary structure was demonstrated by circular dichroism (CD) and high field NMR spectroscopy. CD spectroscopy also showed that the two proteins differed in their stability at pH 3 and in their ability to refold after heating to 95 degrees C. Thus, Pru p 1 was unfolded at pH 3 even at 25 degrees C but was able to refold after heating to 95 degrees C at pH 7.5. In contrast, Pru p 3 was unable to refold after heating under neutral conditions but readily refolded after heating at pH 3.

Apple (Malus domestica) is the most widely cultivated fruit crop in Europe and frequently causes allergic reactions with a variable degree of severity. So far, four apple allergens Mal d 1, Mal d 2, Mal d 3 and Mal d 4 have been identified. Mal d 1, a Bet v 1 related allergen, and Mal d 4, apple profilin, are sensitive to proteolytic degradation, whereas Mal d 2, a thaumatin-like protein and Mal d 3, a nonspecific lipid transfer protein, are rather stable to proteolytic processes. Mal d 1 and Mal d 4 were purified after expression in Escherichia coli expression system, while Mal d 2 and Mal d 3 were purified from apple fruit tissue. All purified proteins were subjected to detailed physicochemical characterisation to confirm their structural integrity and maintained IgE binding capacity. Detailed investigations of carbohydrate moieties of Mal d 2 demonstrated their involvement in the overall IgE binding capacity of this allergen. It was concluded that the folded structure and IgE binding capacity of all four allergens were preserved during purification.