T cell-dependent and -independent expression of intestinal epithelial cell-related molecules in rats infected with the nematode Nippostrongylus brasiliensis.

To determine how T cells of thymic origin regulate the intestinal mucous response induced by nematode infection, mucin production and goblet cell-specific secretory peptide expression were examined in euthymic rnu/+ and athymic rnu/rnu rats infected with the nematode Nippostrongylus brasiliensis. Euthymic rats showed transient goblet cell hyperplasia and upregulation of mucin production, which returned to preinfection levels by 21 days postinfection, when nematodes had been rejected from the intestine. In athymic rats, which failed to reject nematodes, goblet cell hyperplasia and accelerated mucin production continued at least until 21 days postinfection. Gene transcription of mucin-core peptide (MUC)-2 and -3 and trefoil factor (TFF)-2 and -3 in the jejunal epithelium was upregulated parallel to the levels of goblet cell hyperplasia in both euthymic and athymic rats. On the other hand, resistin-like molecule (Relm)beta, sialyltransferase Siat4c and sulfotransferase 3ST1 showed significantly higher transcription levels in euthymic than in athymic rats at 7 and/or 10 days postinfection. These results suggest that the induction of intestinal mucin production occurs without the activation of thymus-derived T cells, while the expression of Relmbeta, Siat4c and 3ST1 in the intestinal epithelial cells seems to be regulated at least partly by thymus-dependent mechanisms.