Differential alterations in the small intestine epithelial cell turnover during acute and chronic infection with Echinostoma caproni (Trematoda)

Abstract

BACKGROUND: The intestinal epithelium plays a multifactorial role in mucosal defense. In this sense, augmented epithelial cell turnover appears as a potential effector mechanism for the rejection of intestinal-dwelling helminths. METHODS: A BrdU pulse-chase experiment was conducted to investigate the infection-induced alterations on epithelial cell kinetics in hosts of high (mouse) and low (rat) compatibility with the intestinal trematode Echinostoma caproni. RESULTS: High levels of crypt-cell proliferation and tissue hyperplasia were observed in the ileum of infected mice, coinciding with the establishment of chronic infections. In contrast, the cell migration rate was about two times higher in the ileum of infected rats compared with controls, with no changes in tissue structure, indicating that an accelerated cell turnover is associated with worm expulsion. CONCLUSION: Our results indicate that E. caproni infection induces a rapid renewal of the intestinal epithelium in the low compatible host that may impair the establishment of proper, stable host-parasite interactions, facilitating worm clearance.