719:
Remote Respiratory Allergen Challenge Increases the Frequency of Small Intestinal Eosinophils in Allergen-Sensitized Mice
Monday, March 5, 2018
South Hall A2 (Convention Center)
Courtney L. Olbrich, Maytal Bivas-Benita, PhD, Jason J. Xenakis, Samuel Maldonado, Evangeline W. Cornwell, PhD, Lisa A. Spencer, PhD FAAAAI
RATIONALE:

Accumulated data suggest that allergic sensitization predisposes susceptible individuals for the development of eosinophilic GI diseases: GI allergic manifestations are observed in asthmatic, allergic rhinitis, and atopic patients; EoE patients exhibit higher rates of aeroallergen sensitization than the general population; and several clinical studies directly implicate aeroallergens in the pathogenesis of EoE. These findings suggest susceptibility to intestinal allergic inflammation may be enhanced by allergen exposure of the skin or respiratory mucosa. However, the interplay between allergen exposure to the skin or respiratory tract and remote eosinophilic GI inflammation remains enigmatic.

METHODS:

Endotracheal administration of allergen to naïve or allergen-sensitized mice was used to provide allergen exposure to the respiratory mucosa while avoiding direct allergen exposure of the GI tract inherent in standard models of airway allergen challenges (i.e. intranasal inhalation or aerosolization). Eosinophilic inflammation was assessed in allergen-challenged mice through complementary approaches, including researcher-blinded counts of histological sections and flow cytometry analyses of disaggregated intestinal tissues.

RESULTS:

Remote allergen challenge increased the frequencies of eosinophils associated with both lamina propria and intraepithelial compartments of the small intestines of allergen-sensitized mice. In contrast, percentages of intestinal CD4+, CD8+, and CD11c+SiglecF- (dendritic) cells remained static following remote (pulmonary) allergen challenge.

CONCLUSIONS:

Remote respiratory allergen exposure increases the frequency of small intestinal eosinophils in systemically allergen-sensitized mice. These data may shed light on the relationship between aeroallergens and eosinophilic gastrointestinal inflammation.