Characterization of allergen driven type-2 cytokine response in an adjuvant-free mouse model of tree nut allergy: Critical role of IL-4 (37.9)

Abstract

Abstract Food allergy is a growing problem of serious proportions with potential for fatality. Specific role of type-2 cytokines in food allergy is not completely understood. Our laboratory has previously developed an adjuvant-free mouse model to study food allergy using hazelnut as a model tree nut. Using this model, the present study was conducted to elucidate the role of selected type-2 cytokines in this model. BALB/c mice were transdermally sensitized with hazelnut protein and systemic IgE antibody responses were confirmed. Subsequently, using short term ex vivo spleen cell culture, allergen driven type-2 cytokine (IL-4, IL-5 and IL-13) responses were studied using ELISA. Here, robust allergen driven, dose dependent, recall IL-4, IL-5 and IL-13 responses were observed. Further, all three type-2 cytokine responses could be largely blocked using anti-CD4 antibodies. Furthermore, BALB/c Stat6 knockout (KO) mice lacked an IL-4 but not IL-5 or IL-13 recall response to hazelnut. In addition, BALB/c Il4 KO mice did not elicit an IgE response to transdermal hazelnut exposure and were resistant to systemic anaphylaxis following oral hazelnut challenge. These data together suggest that: transdermal exposure to hazelnut results in activation of IL-4, IL-5 and IL-13 by CD4+spleen cells; andonly IL-4, which is STAT-6 dependent, is required for food allergy phenotypes studied in this model. Funding: Michigan State University, Michigan Agricultural Experiment Station.