Expansion of Antigen- Specific Memory Cells as a Potential Booster for Food Tolerance Induction

Abstract

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.