Allergen-Specific T Cells in IgE-Mediated Food Allergy

Aziza Saidova, Ahuva Magder Hershkop, Marta Ponce, Thomas Eiwegger

Food allergy is the major reason for severe anaphylaxis in childhood and adolescence. Currently, effective and safe treatments for food allergy are unavailable. Allergen-specific CD4+ T cells have a pivotal role in causing and maintaining the allergic response to food allergens. The purpose of this review is to provide an overview on the role of allergen-specific T cells in food allergy during allergic sensitization, natural tolerance development and allergen immunotherapy. Allergen-specific T cells in the context of food allergy are predominantly of a Th2 type with slightly different surface marker expression patterns in different food allergies. During the process of reverting food allergy to a status of tolerance or sustained unresponsiveness there is a loss of this Th2 committed compartment with an asymptotic approximation to a regulatory and Th0/Th1 dominated compartment seen in non-allergic individuals. This process is accompanied by a significant reduction of absolute frequencies of allergen-specific T cells. Particularly, regulatory T cells may provide significant help to achieve sustained control of the effector cell populations via suppression of effector cell function and possibly induction of blocking antibodies.