IL-33 Induces Murine Intestinal Goblet Cell Differentiation Indirectly via Innate Lymphoid Cell IL-13 Secretion [MUCOSAL IMMUNOLOGY]

Regulation of the intestinal mucus layer by goblet cells is important for preventing inflammation and controlling infection. IL-33, a cytokine upregulated in inflammatory bowel disease and helminth infection, induces intestinal goblet cells, but the mechanism remains unclear. Enteroids are three-dimensional structures of primary small intestinal epithelial cells that contain all differentiated intestinal epithelial cell types. We developed an enteroid–immune cell coculture model to determine the mechanism through which IL-33 affects intestinal goblet cell differentiation. We report that IL-33 does not directly induce goblet cell differentiation in murine enteroids; however, IL-13, a cytokine induced by IL-33, markedly induces goblet cells and gene expression consistent with goblet cell differentiation. When enteroids are cocultured with CD90⁺ mesenteric lymph node cells from IL-33–treated mice, IL-33 then induces IL-13 secretion by group 2 innate lymphoid cells and enteroid gene expression consistent with goblet cell differentiation. In cocultures, IL-33–induced Muc2 expression is dependent on enteroid Il4ra expression, demonstrating a requirement for IL-13 signaling in epithelial cells. In vivo, IL-33–induced intestinal goblet cell hyperplasia is dependent on IL-13. These studies demonstrate that IL-33 induces intestinal goblet cell differentiation not through direct action on epithelial cells but indirectly through IL-13 production by goup 2 innate lymphoid cells.

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