Depletion of Eosinophils Block the Development of Food Allergy Early in Life

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Presentation Time: 10:30 AM - 10:45 AM
Abstract ID: 4486 - B

Presenting Author:
Haoran Gao , postdoc appointee at Indiana Univ. Sch. of Med.

Abstract:

Although mechanisms of food allergy have been studied in several mouse models, roles for eosinophils in development of food allergy are unknown. We hypothesized that depletion of eosinophils block the induction of food allergy. In a model with skin barrier mutations, eosinophils were specifically depleted in neonatal iPhil^+/- FT^+/- mice by diphtheria toxin (DTX) injections on postnatal days (PND) 3, 4, 7, 10, 12, 14, and 17. The pups with or without DTX treatment were sensitized by skin co-exposure to detergent (4% SDS), peanut extract (PNE), and Alternaria alternata (Alt) on PND 6, 8, 11, 15, and 18. On PND 19, pups were orally challenged with PNE, and anaphylaxis was assessed by a drop in rectal temperature. Tissues were collected to examine blood eosinophil numbers and mediators of allergic inflammation. DTX treatment, during skin exposures to allergen, depleted eosinophils in blood and bone marrow in iPhil^+/- FT^+/- pups. Depletion of eosinophils by DTX-treatment blocked oral PNE-induced anaphylaxis in the skin-sensitized iPhil^+/- FT^+/- pups as compared to pups with eosinophils (FT^+/- pups and iPhil^+/- FT^+/- pups without DTX). Depletion of eosinophils also reduced PNE-specific IgE. Our results indicate that eosinophils were necessary for the induction of allergen-specific IgE and food allergy. Further investigations are ongoing to examine the underlying mechanisms of eosinophil function in the skin during the induction of food allergy.