Three distinct antigens associated with human T-lymphocyte-mediated cytolysis: LFA-1, LFA-2, and LFA-3.
Monoclonal antibodies were prepared to anti-HLA-DR cytolytic T lymphocytes (CTLs) and screened for inhibition of CTL-mediated killing. Binding of monoclonal antibodies to four types of molecules, LFA-1, LFA-2, LFA-3, and HLA-DR, inhibited killing, suggesting that these molecules participate in the CTL-target cell interaction. The antigens were characterized by immunoprecipitation, crosslinking, NaDodSO4/polyacrylamide gel electrophoresis, and immunofluorescence flow cytometry. The LFA-1 antigen contains alpha and beta polypeptide chains of Mr 177,000 and 95,000 that are noncovalently associated in an alpha 1 beta 1 structure. It is present on both B and T lymphocytes and marks subpopulations that differ in quantitative expression. Human LFA-1 appears to be the homologue of mouse LFA-1. Human LFA-2 is of Mr 49,000 with a minor component of Mr 36,000. It is expressed on CTL lines but not on a B-cell line and in peripheral blood preferentially on T lymphocytes. Human LFA-3 is of Mr 60,000 and is expressed on both B and T lymphocytes.
D000818:Animals; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis*; D002460:Cell Line; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D006825:Hybridomas; D051379:Mice; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II