Immunotherapy in the treatment of food allergy: focus on oral tolerance

PURPOSE OF REVIEWFood allergy is a serious and growing problem. Although the current standard of care for patients with food allergies is based on avoidance of the trigger, increased understanding of the mechanisms involved in oral tolerance has shifted focus of treatment and prevention toward inducing tolerance. Here we discuss the relationship of food allergy to oral tolerance and review recent oral tolerance studies, focusing on the mechanistic role of antigen presenting cells and the generation of regulatory T cells in mice and humans. RECENT FINDINGSSpecialized intestinal antigen presenting cells are conditioned by spatial and soluble microenvironmental factors to promote tolerance to dietary antigen primarily via the induction of regulatory T cells. Retinoic acid, a vitamin A metabolite, has been recently identified as a key environmental factor in this process. SUMMARYFuture clinical trials for food allergy immunotherapy will benefit from approaches, which target the oral tolerance pathways currently being elucidated.