Isolation of spontaneous and interferon inducible natural killer like cells from human colonic mucosa: lysis of lymphoid and autologous epithelial target cells.

Viable mononuclear and epithelial cells were dispersed from human colonic tissue by treatment with collagenase and ethylene diamino-tetra acetate (EDTA) and separated by centrifugal elutriation. Using a single cell cytotoxic assay, functional endogenous and interferon responsive mononuclear cytotoxic cells were detected. Compared to peripheral blood lymphocyte associated killer cells that had been exposed to similar treatment, these colonic killer cells demonstrated lower efficiency cytotoxicity of Molt-4 target cells. Furthermore, inefficient, but interferon responsive cytotoxic cells were present which bound and lysed freshly isolated autologous epithelial cells. The cytotoxicity of these colonic mononuclear natural killer (NK) like cells appeared specific in that cells bound but did not lyse NK resistant Raji cells, even after interferon activation.