title: The MRC OX-44 antigen marks a functionally relevant subset among rat thymocytes.
abstract: A monoclonal antibody called MRC OX-44 is described that labels all myeloid cells and peripheral lymphoid cells but only 12% of thymocytes. The OX-44+ thymic cells include most if not all cells found in the medulla but only a small fraction of the cortical cells. Together with CD4 and CD8 antigens, seven subsets of thymic cell were defined and it was notable that most CD4- CD8- cells were OX-44+ whereas almost all CD4+ CD8+ cells were OX-44-. In functional tests, the OX-44+ cells accounted for all proliferation by thymocytes when stimulated by allogeneic spleen cells or concanavalin A plus growth factors and OX-44- cells were completely negative in these assays. Also, in tests for thymopoiesis after intra-thymic injection of cells, all activity was OX-44+. It seems possible that the OX-44+ set may include all functionally relevant cells in the rat thymus.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D003713:Dendritic Cells / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000145:classification / Q000166:cytology / Q000276:immunology; D008970:Molecular Weight; D009000:Monocytes / Q000145:classification / Q000166:cytology / Q000276:immunology; D051381:Rats; D012038:Regeneration; D013601:T-Lymphocytes / Q000145:classification* / Q000166:cytology / Q000276:immunology; D013950:Thymus Gland / Q000166:cytology* / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface