title: Acquisition of specific cytotoxic activity by human T4+ T lymphocytes in culture.
abstract: Mature human T lymphocytes can be separated by monoclonal antibodies OKT4 and OKT8 according to their surface phenotypes into T4+T8- and T4-T8+ subsets. From short-term experiments using bulk cultures, the helper/inducer function has been assigned to the T4+T8- subset and the cytotoxic/suppressor function to the T4-T8+ subset. Thus if T lymphocytes are separated after stimulation in a mixed lymphocyte reaction (MLR), the entire cytotoxic activity is found in the T4-T8+ fraction whereas the T4+T8- fraction shows no detectable cytotoxicity. If, however, T lymphocytes are cloned after MLR and grown in long-term culture, a surprisingly large fraction of T4+ T lymphocyte clones (TLC) shows cytotoxic activity. Here we report that T4+ TLC can acquire specific cytotoxicity during in vitro cultivation.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis; D002478:Cells, Cultured / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface