Intraepithelial lymphocytes from villus tip and crypt portions of the murine small intestine show distinct characteristics

Abstract

Background & Aims: Intraepithelial lymphocytes (IELs) are located between epithelial cells that are thought to display unique features and functions at the small intestinal villus tip and crypt levels. We have addressed whether the spatial differences in the intestinal epithelium extend to IELs and subsequent cross-talk between IELs and epithelial cells. Methods: IELs were isolated from villus tip and crypt portions of mouse small intestine and then compared for spontaneous cytokine production and responsiveness to interleukin (IL)-2 and/or IL-7. Results: No difference was observed between number of αβ IELs in villus tips and crypts, whereas a trend toward increased frequencies of IELs bearing the γδ form of T-cell receptor was noted in villus tips. Interestingly, the number of αβ IELs producing interferon gamma and IL-5 was significantly reduced in the cells from crypts compared with villus tips. Furthermore, villus tip αβ IELs exhibited higher responses to stimulation signals provided by IL-2 and/or IL-7 than their crypt counterpart. Such functional differences were not observed with γδ IELs from the two intestinal sites. Conclusions: Distinct molecular cross-talk between IELs and epithelial cells occurs in intestinal villus tips and crypts. GASTROENTEROLOGY 1998;115:866-873