title: Phenotypic modulation of T-lymphoblastic leukaemic cells with phorbol ester and leucocyte conditioned medium.
abstract: Human T-lymphoblastic leukaemic cell line Karpas-45 (K-45) can be induced by phorbol 12-myristate 13-acetate (PMA) to become phenotypically more mature. Marker studies show that the percentages of E-rosette-positive (E+) and UCHT1+ cells are increased after exposure to PMA. Fluorescence of UCHT4+ and 2D1+ cells is increased although their percentages remain almost unchanged. OKT4+ and peanut agglutinin (PNA)-positive cells are greatly reduced. Terminal deoxynucleotidyl transferase (TdT) becomes negative. PMA treatment of K-45 cells after deletion of UCHT4+ cells suggest that marker changes detected by UCHT2, OKT4 and sheep red blood cells (SRBC) occur mainly in the UCHT4+ cells. The proliferation of PMA-treated K-45 cells is dramatically inhibited and the cell size becomes smaller. These results indicate that K-45 cells are induced to differentiate phenotypically towards a suppressor/cytotoxic T cell. However functional maturation can not be demonstrated. Phytohemagglutinin-stimulated leucocyte conditioned medium (LCM) is able to suppress DNA synthesis of K-45 cells and reduce the PNA+ proportion. It seems that LCM can induce a limited degree of differentiation of K-45 cells.
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D002460:Cell Line; D005260:Female; D005312:Fetal Blood; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007945:Leukemia, Lymphoid / Q000276:immunology / Q000473:pathology*; D008214:Lymphocytes / Q000166:cytology*; D010641:Phenotype; D010704:Phorbols / Q000494:pharmacology*; D011247:Pregnancy; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000166:cytology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D010704:Phorbols; D013755:Tetradecanoylphorbol Acetate