The early appearance of specific cytotoxic T cells in murine gut mucosa.

Using a new technique for isolating lymphoid cells from the lamina propria of murine small intestine, we have examined the appearance of specific cytotoxic T cells in the gut following intraperitoneal immunization with an allogenic tumour. Specific cytotoxic T cells appeared in the lamina propria at a time when there are very few cytotoxic lymphocytes in any of the organized lymphoid tissues. Greater levels of cytotoxicity were found in the gut compared with any other site for at least 3 weeks following a single injection of tumour cells.