Intraepithelial lymphocytes contain virus-specific, MHC-restricted cytotoxic cell precursors after gut mucosal immunization with reovirus serotype 1/Lang.

Reovirus 1 has been intraduodenally administered to mice to determine whether virus-specific cytotoxic cells can be elicited within the intestinal epithelium. We have found that reovirus-stimulated, but not control mice, generate virus-specific cytotoxic effector cells when isolated intraepithelial lymphocytes are restimulated in vitro. These effector cells are restricted by major histocompatibility complex (MHC) class I determinants and thus appear to utilize the T cell antigen receptor and to be of the T cell lineage. These results raise the possibility that cytotoxic T lymphocytes (CTL) may be an important component of the host immune response in the intestinal epithelium.