title: Ly-49 mediates EL4 lymphoma adhesion to isolated class I major histocompatibility complex molecules.
abstract: Ly-49 is a recently identified cell surface molecule expressed on a subpopulation of natural killer (NK) cells and certain T lymphomas. It has been suggested, based on gene transfection and antibody blocking studies, that Ly-49 is a negative regulator of NK lytic activity, possibly through an interaction with target cell class I molecules. However, it has not been demonstrated that class I molecules indeed serve as ligands for Ly-49. We have found that T lymphomas expressing Ly-49 bind isolated class I major histocompatibility complex (MHC) molecules but not class II molecules immobilized on plastic. Adhesion to class I molecules was not found with T lymphomas lacking Ly-49 expression. The Ly-49 expressing EL4 lymphoma bound Dd, Dk, and Kb, but not Kd, Kk, or Db, thus demonstrating a restricted pattern of class I adhesion. The observed cell adhesion was class I density dependent, and binding to Dd and Dk was extensively inhibited by the A1 monoclonal antibody directed against Ly-49. These results provide direct evidence for Ly-49 serving as a receptor for a subset of class I MHC molecules.
authors.affiliation: Department of Immunology, University of Alberta, Edmonton, Canada.
authors.forename: K P
authors.initials: KP
authors.lastname: Kane
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000276:immunology*; D002460:Cell Line; D006681:HLA-D Antigens / Q000276:immunology / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D006825:Hybridomas / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D007700:Kinetics; D008223:Lymphoma; D016399:Lymphoma, T-Cell / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D014407:Tumor Cells, Cultured
chemical_list: D006681:HLA-D Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D008565:Membrane Proteins