title: Subpopulations of normal and leukemic human thymocytes: an analysis with the use of monoclonal antibodies.
abstract: Combinations of antibodies to membrane antigens and to terminal deoxynucleotidyl transferase (TdT) were used to study human thymocyte and bone marrow subpopulations and leukemia cells. Cortical thymocytes were TdT+ and expressed T-cell antigens (HuTLA+), a thymocyte-specific antigen (HTA-1+), and a leukocyte antigen (HLe-l++) but lacked detectable HLA-A,B,C and la (HLA-D) antigens. In contrast, medullary thymocytes were TdT-, HuTLA+, HTA-1-, HLe-l++. A small subpopulation of larger, probably immature, thymocytes were strongly TdT+, HuTLA+, la-, HTA-1-, HLe-l +/-. Many blast cells from cases of thymic acute lymphoblastic leukemia (Thy-ALL) showed the phenotype of this small subset, and only a proportion of Thy-ALL blast cells exhibited HTA-1 and HLe-l antigens as strongly as was observed on normal cortical thymocytes. In contrast, TdT+ cells observed in normal juvenile bone marrow were HuTLA, HTA-1-, HLA+, la+. This phenotype corresponded to the phenotype of the common form of ALL (non-T, non-B) and indicated that further studies are necessary to analyze the differentiation of bone marrow precursors to thymic cells.
mesh_terms: D000906:Antibodies / Q000276:immunology*; D000936:Antigen-Antibody Complex; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002999:Clone Cells; D003584:Cytological Techniques; D006801:Humans; D007158:Immunologic Techniques; D007945:Leukemia, Lymphoid / Q000175:diagnosis / Q000276:immunology / Q000473:pathology*; D008221:Lymphoid Tissue / Q000276:immunology / Q000473:pathology; D010641:Phenotype; D013601:T-Lymphocytes / Q000473:pathology*; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology
chemical_list: D000906:Antibodies; D000936:Antigen-Antibody Complex