Consecutive food and respiratory allergies amplify systemic and gut but not lung outcomes in mouse - 04/04/15

Increasing clinical data suggest a link between food allergy and the later development of respiratory allergy. This progression may be triggered by exposures to different allergens but the mechanism implicated remains unknown. This study aimed to identify the impact of a first exposure to food allergen on the development of a new form of allergy caused by exposure to a novel allergen using a mouse model.

In our model, mice were intraperitoneally sensitized to wheat proteins (modified gliadins) to induce a systemic response, then they were exposed orally to the same allergen and finally they were intranasally exposed to HDM (Dermatophagoides farinae extract) a respiratory allergen without adjuvant to assess an impact on lung mucosa.

After food and respiratory allergen exposures, mice displayed stronger amount of blood markers: IgE specific and histamine. Moreover, splenocyte secretion of IL-4 and IL-17 were increased whereas weaker levels of IFNg were observed. In parallel, Peyer patches lymphocytes secreted higher amount of IL-4 with a decreased in IFNg, IL-10 and TGF-b productions. These mice exhibited intestine damages, higher paracellular flux and modification of transcellular permeability. In contrast, airway hyperresponsiveness, inflammatory cells and cytokines in lung remained unchanged compared to the respiratory allergy model.

We show that dual exposure induces a raise in specific IgE and local Th2 and Th17 cytokines secretion before triggering phase. During the latter, gut morphology and functions were affected but not lung in dual exposed mice compared to single one underlying the organospecific impact. Altogether, our data make a step further in the elucidation of the mechanisms linking allergy history to immunological and clinical status potentially linked to atopic march development.