title: Cell surface phenotype of cytolytic T lymphocyte precursors in aged nude mice.
abstract: The cell surface phenotype of cytolytic T lymphocyte precursors (CTL-P) in congenitally athymic C57BL/6 nu/nu mice has been investigated. CTL-P were detected and quantitated in a limited dilution mixed leukocyte microculture assay system supplemented with interleukin 2. Minimal estimates of the frequency of CTL-P among nylon wool passed (NWP) nude spleen cells were obtained following elimination of Thy-1-bearing or Lyt-2-bearing cells with monoclonal antibodies plus complement. Alternatively, NWP spleen cells bearing Thy-1 or Lyt-2 were positively selected on a cell sorter and assayed for CTL-P frequency. Both positive and negative selection techniques demonstrated that essentially all (greater than 98%) CTL-P in NWP nude spleen expressed Thy-1 and that the majority (80-90%) expressed Lyt-2. In control NWP spleen cells from normal C57BL/6 mice, greater than 98% of CTL-P were positive for both Thy-1 and Lyt-2. These data demonstrate that most functional alloreactive CTL-P developing in the apparent absence of thymic influence already express both Thy-1 and Lyt-2 prior to exposure to antigen.
mesh_terms: D000375:Aging; D000818:Animals; D000950:Antigens, Ly / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology*; D002454:Cell Differentiation; D003602:Cytotoxicity, Immunologic; D008565:Membrane Proteins / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008819:Mice, Nude; D010641:Phenotype; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D018800:Thy-1 Antigens
chemical_list: D000950:Antigens, Ly; D000954:Antigens, Surface; D008565:Membrane Proteins; D018800:Thy-1 Antigens