title: Human mucosal T-cell cytotoxicity.
abstract: Non-major histocompatibility complex-restricted cytotoxicity triggered by antibodies to the CD3 component of the human T-cell receptor complex is thought to be an indirect measure of in vivo primed cytotoxic T-cell activity. We have used this technique to examine the lytic activity of freshly isolated T cells from noninflamed human colonic mucosa. Anti-CD3-triggered T-cell (anti-CD3-T) cytotoxicity was found in all mucosal specimens studied. The mucosal anti-CD3-T effectors do not have Fc receptors for immunoglobulin G, and are therefore distinct from T gamma cells, which mediate antibody-dependent cellular cytotoxicity. The surface antigen phenotype of mucosal anti-CD3-Ts is CD2+, CD3+, CD8+, CD4-, CD16-, and Leu7-. In contrast, peripheral blood anti-CD3-T effectors are Leu7+. Although non-major histocompatibility complex-restricted, mucosal anti-CD3-T cytotoxicity has considerable target specificity, which differs from that of natural killer and lymphokine-activated killer cells. The profile of target cell susceptibility and the inhibitory effects of anti-CD45 antibody suggest that the CD45 molecule on the effector cell may be an important determinant of anti-CD3-T sensitivity. As anti-CD3-triggered lysis may be a marker of in vivo primed mucosal T cells of undetermined antigen specificity, this technique might have important implications in inflammatory bowel disease, where the antigen(s) inciting the mucosal immune reactivity is not certain.
mesh_terms: D000954:Antigens, Surface / Q000276:immunology; D003106:Colon / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006801:Humans; D007413:Intestinal Mucosa / Q000276:immunology*; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D000939:Epitopes; D011948:Receptors, Antigen, T-Cell