title: Functional characterization of human thymocyte subpopulations separated by density gradient centrifugation.
abstract: A bovine serum albumin gradient was used to separate two populations of human thymocytes--a minority population (8%) of large thymocytes (LT) and a majority population (92%) of small thymocytes (ST). Fifty per cent of LT cells were in the S, G2 or M phases of the cell cycle compared to 5% of ST cells and 15% of unfractionated thymocytes. LT cells proliferated in response to T cell mitogens and included all of the T colony precursor cells (TCPC). In contrast, ST cells proliferated with mitogens only in the presence of added T cell growth factors and contained none of the thymocyte TCPC. ST cells neither helped nor suppressed the function of LT cells in any assay. This separation technique has provided a rapid method for isolating functionally distinct thymic lymphocyte subpopulations and permitted a further definition of the TCPC in the human thymus. Furthermore it should prove useful in studies of thymocytes at different stages of the cell cycle.
mesh_terms: D000293:Adolescent; D000911:Antibodies, Monoclonal / Q000276:immunology; D001666:Binding Sites, Antibody; D002453:Cell Cycle; D002455:Cell Division; D002469:Cell Separation; D002499:Centrifugation, Density Gradient; D002648:Child; D002675:Child, Preschool; D002999:Clone Cells; D006801:Humans; D007223:Infant; D007376:Interleukin-2 / Q000494:pharmacology; D007399:Interphase; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000145:classification* / Q000166:cytology / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D008934:Mitogens