Although implicated in the disease, the specific contributions of FcεRI and IL-13 to the pathogenesis of peanut-induced intestinal allergy are not well defined.
To determine the contributions of FcεRI, IL-13, and mast cells to the development of intestinal mucosal responses in a mouse model of peanut-induced intestinal allergy.
Sensitized wild-type (WT), FcεRI-deficient (FcεRI−/−), and mast cell-deficient (KitW-sh/W-sh) mice received peanut orally every day for 1 week. Bone marrow-derived mast cells (BMMC) from WT, FcεRI−/−, IL- 4−/−, IL-13−/−, and IL- 4/IL-13−/− mice were differentiated and transferred into WT, FcεRI−/−, and KitW-sh/W-sh recipients. BMMC from WT and UBI-GFP/BL6 mice were differentiated and transferred into WT and KitW-sh/W-sh mice. Blockade of IL-13 was achieved using IL- 13Ra2-IgG fusion protein.
FcεRI−/− mice showed decreased intestinal inflammation (mast cell and eosinophil numbers) and goblet cell metaplasia, and reduced levels of IL-4, IL-6, IL-13, and IL-17A mRNA expression in the jejunum. Transfer of WT BMMC to FcεRI−/− recipients restored their ability to develop intestinal allergic responses compared to transfer of FcεRI−/−, IL-13−/−, or IL-4/IL-13−/−BMMC. FcεRI−/− mice exhibited lower IL-13 levels and treatment of WT mice with IL-13Rα2 prevented peanut-induced intestinal allergy and inflammation.
These data indicate that the development of peanut-induced intestinal allergy is mediated through a mast cell-dependent, IgE-FcεRI-IL-13 pathway. Targeting IL-13 may be a potential treatment for IgE-mediated peanut allergic responses in the intestine.