Trichinella spiralis infection induces chronic small intestinal inflammation and around the time of worm expulsion, the following occur: villus atrophy, crypt hyperplasia, increase in Paneth, goblet and mast cell numbers and increases in mucosal expression of all three isoforms of transforming growth factor beta (TGF-[Beta]). However the in vivo role of TGF-[Beta] and Paneth cell-secreted antimicrobial peptides in chronic intestinal inflammation remain to be fully characterised. The main aim of these studies was to investigate the small intestinal epithelial responses to TGF-[Beta] and Paneth cell-secreted antimicrobial peptides in T. spiralis infection. The first experiment, the investigation of the role of TGF-[beta] was undertaken using a mouse model with inactivation of the transforming growth factor beta receptor II gene in intestinal epithelial cells (Vil-Cre; TGFBR2FIOxIFIOX). These studies showed there was delayed worm expulsion in Vil-Cre;TGFBR2Flox/Flox mice compared to controls. Histological analysis showed a significant reduction in intestinal mast cell counts in Vil-Cre;TGFBR2Flox/Flox mice when compared to wild type mice.