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Because of the high social impact of Food allergy, it is of great importance to correctly diagnose this disease using reliable tests. Knowledge of the allergenicity properties of proteins, how they react in the body and in diagnostic tests is necessary to adequately assess the potential immunogenicity of both natural foods and those produced through biotechnological processes. Thus, our aim was to analyze the factors that influence the protein extraction of foods in terms of, immunogenicity and immunoassays sensitivity. Peanut proteins were extracted using four distinct extraction buffers (physiological saline, tris buffer, borate buffer with and without β-mercaptoethanol), the protein concentration was determined by the Lowry method and polyacrylamide electrophoresis (SDS-PAGE) was used to compare the protein profile of each extract. The immunogenicity of each extract was verified by sensitizing two mouse strains (Balb/c and C57/BL6) with solution containing 100μg of the extracted proteins and determined by ELISA. Results show that extraction with the distinct buffers resulted in protein solutions with different yields and profiles. The immunogenicity of the different extracts also demonstrated distinct patterns that varied depending on the extraction methods, mouse strain and in-vitro test. Immunoreactivity varied in accordance to the protein extract used to coat the microtitration plates. In conclusion, the protein profile in the extracts is critically influenced by the salt composition and pH of the extraction buffers, this in turn influences both in vivo immunogenicity and in vitro immunoreactivity.

Approximately 3% of children in Western countries are diagnosed with peanut allergy, a likely lifelong disease. The preferred treatment for food allergy is allergen avoidance. However, oral immunotherapy is an FDA-approved treatment to re-induce tolerance, still, not all patients respond as expected. Thus, the aim of this work is to evaluate whether the association of an antigen-specific tolerogenic (oral tolerance) bystander effect can ameliorate the recovery of inflamed intestinal mucosa. Adult male C57BL/6 mice were divided into five groups, four of which were submitted to an intestinal inflammation induction protocol to peanuts. After sensitization, experimental groups were orally challenged with either peanuts or a hybrid diet (peanuts + mouse chow). In a second stage, groups were sensitized, challenged with peanuts, and then received either peanuts, hybrid diet, or ovalbumin chow during the recovery period of the inflamed mucosa. Results showed no changes in diet intake and body weight. Polyisotypic anti-peanut IgG and IgG1 were significantly increased in the serum from animals in allergic groups. The group that received the hybrid diet showed an increase in CD4+CD25+Foxp3+ regulatory T cells, as well as in B220+CD3-CD27+ memory B cells. Histology of the duodenum showed a decrease in intraepithelial leukocytes in animals who received hybrid diet. Together, our results show that when the tolerogen is added to a diet containing the allergen, it can ameliorate the induction of local inflammation. Simultaneously offering the allergen with a tolerated food increased the mucosal recovery due to the expansion of previously induced memory cells.