title: Cytofluorometric isolation of I937, an Ia antigen-bearing variant of the Ia-negative human monocytic cell line U937.
abstract: Cells of the human monocyte cell line U937 are generally considered devoid of any Ia antigens on their surface. In analyzing U937 cells with a large panel of monoclonal anti-human Ia antibodies by flow cytometry, we detected a small number of cells that appeared to react with antibodies to HLA-DR and HLA-DS/DC molecules. These Ia-positive cells were isolated and were cloned, resulting in a human monocyte cell line that expresses high levels of Ia antigens. We analyzed these antigens by one- and two-dimensional polyacrylamide gel electrophoresis, after radiolabeling and immunoprecipitation. Three distinct Ia molecules, alpha 1 beta 1, alpha 1 beta 3 (HLA-DR-like), and alpha 2 beta 2 (HLA-DC/DS-like) are synthesized by I937 cells, alpha 1 beta 3 molecule being the predominant species. The Ia antigen-bearing human monocyte cell line is expected to be useful for studying events involved in antigen presentation.
mesh_terms: D000954:Antigens, Surface / Q000032:analysis; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry / Q000379:methods; D006680:HLA Antigens / Q000032:analysis; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000276:immunology; D009000:Monocytes / Q000166:cytology / Q000276:immunology*; D010641:Phenotype
chemical_list: D000954:Antigens, Surface; D006680:HLA Antigens; D000949:Histocompatibility Antigens Class II