Inhibition of natural killer-cell mediated cytolysis with monoclonal antibodies to restricted and non-restricted epitopes of the leucocyte common antigen.
Three monoclonal antibodies recognizing different epitopes of the leucocyte common molecule, CMRF-11 (against the restricted or B-220 leucocyte common molecule), CMRF-12 and CMRF-26 [each against a different epitope on the non-restricted or T200 leucocyte common (CD45) molecule], were tested for their effects on lymphocyte cytotoxicity. The individual monoclonal antibodies inhibited human natural killer cell-mediated cytolysis (NK-CMC) weakly, but a mixture of CMRF-11 + 12 + 26 antibodies inhibited cytolysis more consistently and to a greater extent. This mixture did not inhibit cytotoxic T lymphocytes derived from secondary mixed lymphocyte cultures. The CMRF-11 + 12 + 26 mix was shown to inhibit a post-conjugate formation stage of lysis at the effector cell level. Inhibition of NK-CMC of a wide range of target cells, including the T-cell lines Jurkat, HSB2 and Molt 4, was demonstrated.
D000911:Antibodies, Monoclonal; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000276:immunology*; D006649:Histocompatibility Antigens / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D017493:Leukocyte Common Antigens; D007959:Lymphocyte Culture Test, Mixed; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006649:Histocompatibility Antigens; D017493:Leukocyte Common Antigens