Abstract Text: Eosinophilic esophagitis (EoE) is a chronic, allergic inflammatory disease of the esophageal mucosa. Type 2 cytokines (i.e., interleukin (IL)-13) are predominant, although treating type 2 inflammation alone in EoE is not successful. Interestingly, EoE biopsy transcriptional signatures reveal upregulation of type I and II interferon (IFN) response, dysregulated immune signaling and downregulation of esophageal-specific genes in EoE patients. However, the role of interferon signaling during EoE remains unresolved. RNA-sequencing was performed using epithelial cells isolated from pediatric patient biopsies following dissociation and removal of CD45+ cells. IFN-γ response was identified as the most significant upregulated pathways in EoE epithelium. To determine the functional implications of interferon exposure, we used in-vitro cell culture models of immortalized esophageal epithelial cells, EPC2-hTERT. IFN-γ-pSTAT1 stimulation significantly increased epithelial cell death via apoptosis (p < 0.001); decreased transepithelial electrical resistance (TEER) (p < 0.05) and increased paracellular permeability to FITC-Dextran (p < 0.05) in air-liquid interface (ALI) culture. Esophageal epithelial organoids treated with IFN-γ exhibited reduced formation rate (p < 0.001), size (p < 0.001), and abnormal pattern of proliferation-differentiation gradient (Ki67-IVL). Further, the treatment triggered upregulation of several genes, including tissue differentiation, epithelial barrier and apoptotic genes replicating the active EoE mucosa. In conclusion, IFN response gene signature enriched in the epithelium of active EoE suggests that upregulated interferon signaling is part of the dysregulated mucosal immune process present in EoE. Beyond EoE, our findings offer new insights into esophageal disorders which may involve increased IFN-γ signaling, including gastroesophageal reflux disease, and Barrett's esophagus.
