Effect of digestion on the immunoreactivity and proinflammatory properties of recombinant peanut allergen Ara h 1

Abstract

Ara h 1 is one of the major allergens existed in peanut, peptides formed in the digestion process of Ara h 1 could induce allergic symptoms and cause local inflammatory. The mechanism of intestine epithelial immune has not been clarified yet. Here we explored the effect of digestion on the immunoreactivity and proinflammatory properties of recombinant Ara h 1 (rAra h 1). rAra h 1 was treated (or untreated) with heat, digested by pepsin. According to the results, in the early period of digestion, both native and heated rAra h 1 were degraded. Q-PCR and Westernblot results revealed that the NF-κB pathway was involved in the cytokine secretion. The proinflammatory effect were less pronounced in the samples treated with heat, demonstrating that digestion, instead of thermal process, could modify the proteins and peptides, which could then play a significant role in the activation of Caco-2 cells via the NF-κB pathway.

Effects of Flavourzyme and Alkaline Protease Treatment on Structure and Allergenicity of Peanut Allergen Ara h 1

“…Tian et al . ( 29 ) emphasised the effects of simulated gastric juice digestion on the immunoreactivity and proinflammatory properties of recombinant Ara h 1. Their results showed that Ara h 1 led to increased cytokine secretion and inflammation through activation of the NF-κB pathway.…”

Purified Clinoptilolite-Tuff as an Efficient Sorbent for Food-Derived Peanut Allergens

“…This contradicts other scientific investigations published, which, irrespective of their degradation by pepsin, describe Ara h 1 fragments as still being toxic when touching the mucosa of the gut. By using a recombinant rAra h 1 form (which was heat-treated, thereby causing structural changes in the protein), Tian et al [ 50 ] showed that heat could reduce the proinflammatory potential of rAra h 1 fragments—an effect also observed in successful pepsin digestion after heat treatment. Experiments were performed with Caco-2 human intestinal epithelial cells, and the activation of IL-8 after the addition of rAra h 1 fragments was analyzed using an ELISA.…”

“…Interestingly, in more than 90% of peanut-sensitive patients, Ara h 1 could be recognized by serum IgE. The location of epitopes also had a clear effect on the allergenic potential: epitopes in the 393–402 and 498–508 regions of Ara h 1 were recognized by 60% and 90% of patients with peanut allergy, respectively [ 50 ]. Our experiments demonstrated the binding of whole peanut to PCT under gastric and intestinal conditions and in the presence of enzymatically inhibited pepsin and pancreatin, respectively.…”

Crosslinked Recombinant-Ara h 1 Catalyzed by Microbial Transglutaminase: Preparation, Structural Characterization and Allergic Assessment

“…Solubility changes, structural alterations and the following allergenicity changes in allergens were easily induced by processing, while the extent of the effects was influenced both by processing procedures and the biochemical properties of the treated allergen. For example, the immunoreactivity of Ara h 1 was reduced after boiling, for the allergen was attacked by water molecules, and aggregates with a significantly lowed Immunoglobulin E (IgE) binding ability were subsequently formed [ 17 , 18 , 19 ]. The immunogenicity of recombinant Ara h 1 (rAra h 1) glycosylated by glucosamine was significantly decreased, because the linear and conformational epitopes were destructed by molecular modifications [ 16 ].…”