Tolerogenic effects of interferon-gamma with induction of allergen-specific interleukin-10-producing regulatory B cell (Br1) changes in non-IgE-mediated food allergy.

In this study, specific oral tolerance induction using interferon-gamma (IFN-γ) could successfully treat food allergies. Allergen-specific IL-10-producing regulatory B cell (Br1) responses are characteristic in immune tolerance of food allergies. The in-vivo effects of IFN-γ on allergen-induced changes in Br1 proportion and numbers in food allergies were investigated. Oral food challenges were conducted and 20 allergic patients to cow's milk were selected. Of these 20 patients, five were treated with IFN-γ and milk (SOTI group), five were treated with only milk, five were treated with only IFN-γ, and five did not receive any treatment. In addition, 10 milk-tolerant subjects were involved in this study. Peripheral blood mononuclear cells (PBMCs) were stimulated using casein and stained for CD5, CD19, annexin V, and IL-10 before and after treatment. Allergy tolerance was induced only in the SOTI group along with induction of allergen-induced Br1 changes. Thus, IFN-γ can show tolerogenic effects in vivo when introduced with an allergen, which may be at least partly due to its effect on allergen-induced Br1 responses.