Both Fc receptors and lymphocyte-function-associated antigen 1 on human T gamma lymphocytes are required for antibody-dependent cellular cytotoxicity (killer cell activity).
A monoclonal antibody, designated CLB-LFA-1/1, directed to the human lymphocyte-function-associated antigen 1 (LFA-1) was raised by immunization of mice with the peripheral blood lymphocytes of a T gamma lymphocytosis patient. The monoclonal antibody was selected by inhibition of the natural killer cell and the antibody-dependent killer cell activity of the patient's T gamma lymphocytes. In addition, the monoclonal antibody was shown to inhibit the cytotoxic activity of T cell clones specific for either class I or class II HLA molecules. The antigen recognized by CLB-LFA-1/1 consisted of three polypeptide chains with molecular weights of 180 000 (alpha), 155 000 and 94 000 (beta). The antibody reacted with T cells, B cells, monocytes and granulocytes, and stained normal T gamma cells and T gamma cells of patients with T gamma lymphocytosis two- to threefold stronger than normal T cells. It was shown that LFA-1 and the Fc receptor on T gamma cells did not comodulate and it is therefore concluded that Fc receptors and LFA-1 are independent membrane structures, both required for the killer cell activity of T gamma cells.
D000911:Antibodies, Monoclonal / Q000276:immunology; D000920:Antibody-Dependent Cell Cytotoxicity; D000941:Antigens; D000954:Antigens, Surface / Q000276:immunology; D002469:Cell Separation; D002999:Clone Cells; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008218:Lymphocytosis / Q000097:blood; D011233:Precipitin Tests; D011961:Receptors, Fc / Q000276:immunology*; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000941:Antigens; D000954:Antigens, Surface; D011961:Receptors, Fc