IL-13-Induced Goblet Cell Antigen Passages (GAP's) Are Required for the Onset of an Acute Food-Induced Anaphylactic Reaction
•GAPs have been implicated in food antigen uptake and apical-basolateral transport to CD103+ dendritic cells within the lamina propria of the small intestine (SI).
•Induction of GAPs is closely associated with mucus secretion.
•Cholinergic agonists such as carbachol (CCh, calcium mobilizing agent) induces mucus secretion and GAP formation through M4AchR-dependent process.
•Goblet cell (GC) hyperplasia and mucus hypersecretion in the SI are observed in food allergic, intestinal IL-13 transgenic and IL-13 treated mice.
•How food allergens cross the SI epithelium and are delivered to the sub-epithelial immune compartment during the onset of food-induced anaphylaxis (FIA) remains largely unknown.
•IL-13 induces GC antigen passages.
•IL-13 driven GAP formation is mediated via a M4AchR-independent pathway.
•Food allergens traffic through GAPs in the SI.
•Antigen passage through GCs in the SI is required for the onset of FIA and is dependent on IL-13.
•Food-induced anaphylaxis was induced in BALB/c mice by i.p. sensitization (OVA 50ug/alum 1mg; 200ul) and repeated oral gavage with OVA (250mg/ml : 200ml) as previously described (1). In some experiments mice received Tropicamide 4 mg/i.p. or 8 Bromo-cADPR 4 mg/i.p. 60 minutes prior to seventh OVA challenge. Evidence of anaphylaxis was measured by rectal thermometry and mast cell activation by measurement of mast cell protease-1 (mMCPT-1) levels in serum.
•Live imaging and GAP quantitation was performed as previously described (3). Rho-dextran (2.5 mg/200 ml PBS) was intraluminally injected 15 min prior to tissue harvest.
•iIL-13 transgenic mouse model: IL-13 is transgenically expressed in the SI epithelium as previously described (2).
•In vitro GAP analysis was performed with LS174T, mucinous colonic adenocarcinoma, that was cultured as previously described (4).