Ovalbumin Modified with Pyrraline, a Maillard Reaction Product, shows Enhanced T-cell Immunogenicity

Abstract

Background: Maillard reaction (MR) modifies food allergens with various glycation structures during thermal processing of foods. Results: We show that pyrraline, a glycation structure, enhances potential allergenicity of ovalbumin, a model allergen, by promoting scavenger receptor class A-mediated allergen uptake by dendritic cells. Conclusion: Pyrraline could act as a pathogenesis-related component in food allergies. Significance: We reveal how MR links to food allergies.

Proteomic characterization of intermediate and advanced glycation end-products in commercial milk samples

“…On the other hand, a reduced digestibility of modified milk proteins may affect the allergic response to specific dairy products; in fact, it has been reported that proteins resistant to digestion may behave as major food allergens [55,56]. Extensive glycation/ glyco-oxidation of surface-exposed residues in specific milk proteins should also per se modulate the allergenic impact of these nutrients [26,57,58].…”

“…Shotgun analysis characterized a variable number of lactosylation sites within each protein; their number increased with harder milk processing conditions. This may lead to a progressive decrease of the milk nutritional value, as it reduces the bioavailability of essential amino acids, and may affect function, digestibility and allergenic potential of individual proteins [14,23,25,26].…”

Glycation of the Major Milk Allergen β‐Lactoglobulin Changes Its Allergenicity by Alterations in Cellular Uptake and Degradation

“…). For instance, the effects of MR on immunogenicity and allergenicity of food allergen OVA have also been studied and have shown an elevated risk of food allergy . We aimed to describe how glycation reaction of the major milk allergen, BLG, influences handling and processing by epithelial and dendritic cells.…”

What makes an allergen?

“…The reaction leads to the modification of proteins with various types of glycation structures. Importantly, glycated OVA induced higher allergen-specific CD4 + T cell responses and IgE production in mice, compared to native OVA [51], suggesting that SR-A transfers its ligands to MHC class II loading pathway in APCs to promote CD4 + T cell activation. SR-A structurally comprises the transmembrane domain, a spacer region, a helical coiled coil domain, a collagenous domain and a C-terminal cysteine-rich domain [52].…”