Award Number: W81XWH-11-1-0507 TITLE: Exploration into the Genetics of Food Allergy

Background: Esophageal fibrosis is a complication of eosinophilic esophagitis (EoE) which has been attributed to both subepithelial fibrosis and to epithelial to mesenchymal transition (EMT), a process by which epithelial cells acquire mesenchymal features. Common to both causes of EoE-fibrosis is the notion that granulocyte-derived TGF-b, induces myofibroblast differentiation of the target cell. To date, the role of esophageal epithelial cells as effector cells in esophageal fibrosis has never been explored. Herein, we investigated consequences of cross-talk between esophageal epithelial cells and fibroblasts, and identified profibrotic cytokines which influence the development of EMT in vitro. Methods and results: Stimulation of primary fetal esophageal fibroblasts (FEF3) with conditioned media (CEM) from esophageal epithelial cells (EPC2-hTERT), primed FEF3 cells to secrete IL-1b and TNFa, but not TGFb. To determine whether these cytokines signaled in a paracrine fashion to esophageal epithelial cells, FEF3 cells were stimulated with CEM, followed by transfer of this fibroblast conditioned media (FCM) to EPC2-hTERT cells. Epithelial FCM stimulation increased expression of mesenchymal markers and reduced E-cadherin expression, features of EMT which were TNFa and IL-1b-dependent. Using organotypic culture models, primary EoE epithelial cells exhibited features of EMT compared to non-EoE cells, corresponding to patterns of EMT in native biopsies. Conclusions: Esophageal epithelial cell and fibroblast cross-talk contributes to esophageal fibrosis. Our results suggest that features of EMT can develop independent of TGF-b and granulocytes, which may have important implications in treatment of EoE. & 2012 Elsevier Inc. All rights reserved. Inc. All rights reserved. tis; EMT, epithelial to mesenchymal transition; IL-1b, interleukin 1-beta; TNFa, tumor owth factor beta; aSMA, alpha smooth muscle actin; CEM, conditioned epithelial media; anotypic cell culture oenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, 34th and Civic : þ267 426 7814. .-L. Wang). E X P E R I M E N T A L C E L L R E S E A R C H 3 1 9 ( 2 0 1 3 ) 8 5 0 – 8 5 9 851