Innate lymphoid cells type 2 in LTP-allergic patients and their modulation during sublingual immunotherapy.

Abstract

Lipid transfer protein allergy induces complex clinical manifestations, often severe or life- threatening in food allergy (FA).1 It is characterised by an immunologic tolerance breakdown to ingested food associated with the immunological response type 2. The innate lymphoid cell type 2 (ILC2) have emerged as key in FA, mainly in animal models.2 ILC2 share morphological characteristics with lymphocytes, with no expression of allergen recognition receptors, with expression of transcription factor GATA- 3, and receptors for IL- 25, IL- 33 and thymic stromal lymphopoietin (TSLP). ILC2 are activated by these cytokines, originating their expansion and production of Th2- cytokines.3 Furthermore, a distinct subset of ILC2 with regulatory function with IL- 10 production, which can be activated by different immunological pathways and by retinoic acid, has been characterised.4 However, the innate immune cell involvement in the allergic disease remains to be elucidated, specifically ILC2 implication in loss of tolerance to food allergens in humans.