title: Phorbol ester-induced modulation of cell surface antigens on U-937 cells in protein-free medium: effect of protein kinase and calmodulin inhibitors.
abstract: Phorbol ester (PMA) induced decrease in cell surface expression of CD4 antigen was potentiated on human monoblastoid cell line U-937 cultured and induced in protein-free culture medium. Down-regulation of the CD4 antigen was partially inhibited by the isoquinoline protein kinase inhibitor H7 and unaffected by the calmodulin inhibitor R24571 (calmidazolium). PMA-induced increase of the monocyte-associated CD14 antigen was dependent the presence of fetal bovine serum (FBS) in culture medium and partially abolished by calmodulin inhibitor R24571. H7 inhibitor partially abrogated this up-regulation in 4 out of 8 induction experiments. PMA-induced down-regulation of MHC class I antigen was found in both FBS-supplemented and protein-free culture media. This effect was partially inhibited by both H7 and R24571 inhibitors.
authors.affiliation: Cancer Research Institute, Slovak Academy of Sciences, Bratislava.
authors.forename: L
authors.initials: L
authors.lastname: Hunáková
authors.forename: J
authors.initials: J
authors.lastname: Sedlák
authors.forename: B
authors.initials: B
authors.lastname: Chorváth
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D015703:Antigens, CD / Q000096:biosynthesis*; D015214:Antigens, Differentiation, Myelomonocytic / Q000096:biosynthesis; D015704:CD4 Antigens / Q000096:biosynthesis; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000502:physiology*; D016895:Culture Media, Serum-Free; D015536:Down-Regulation / Q000187:drug effects; D005434:Flow Cytometry; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D018950:Lipopolysaccharide Receptors; D016403:Lymphoma, Large B-Cell, Diffuse / Q000276:immunology*; D010879:Piperazines / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000502:physiology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015704:CD4 Antigens; D002147:Calmodulin; D016895:Culture Media, Serum-Free; D015395:Histocompatibility Antigens Class I; D007093:Imidazoles; D007546:Isoquinolines; D018950:Lipopolysaccharide Receptors; D010879:Piperazines; D047428:Protein Kinase Inhibitors; C031938:calmidazolium; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011494:Protein Kinases; D013755:Tetradecanoylphorbol Acetate