title: Molecular mechanisms involved in CD43-mediated apoptosis of TF-1 cells. Roles of transcription Daxx expression, and adhesion molecules.
abstract: CD43 (leukosialin, sialophorin), an abundant leukocyte surface sialoglycoprotein, regulates leukocyte adhesion and transmits activating signals in T cells and dendritic cells. Immobilized anti-CD43 monoclonal antibody (mAb) MEM-59 has been previously shown to induce apoptosis of hematopoietic progenitors. In this study we show that it also triggers apoptosis of the myeloid progenitor-derived cell line TF-1. The kinetics of the MEM-59-induced apoptosis were unusually slow, with the first apoptotic cells appearing 36-48 h after their contact with the immobilized antibody; in 5 days, 90% of the cells were dead. CD43-mediated apoptosis was enhanced by coimmobilized anti-CD45 mAb and partly suppressed by coimmobilized anti-CD50 (ICAM-3) or anti-CD99 mAb. The MEM-59-triggered apoptosis of TF-1 cells was also inhibited by the overexpression of an apoptotic regulator, Daxx. CD43-mediated apoptosis was preceded by the repression of the DNA binding activity of the transcription factor AP-1. DNA array screening revealed that the expression of several genes encoding apoptosis-regulating proteins, including 14-3-3 proteins and the granulocyte macrophage colony-stimulating factor (GM-CSF) receptor beta-subunit, was repressed in TF-1 cells bound to immobilized MEM-59. The down-regulation of 14-3-3 proteins and GM-CSF receptor beta was accompanied by translocation of the proapoptotic protein Bad to the mitochondria. These results suggest that engagement of CD43 may, presumably through the repressing transcription, initiate a Bad-dependent apoptotic pathway.
authors.affiliation: Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague 4, CZ-14220, Czech Republic.
authors.forename: Lukás
authors.initials: L
authors.lastname: Cermák
authors.forename: Sárka
authors.initials: S
authors.lastname: Símová
authors.forename: Alexandros
authors.initials: A
authors.lastname: Pintzas
authors.forename: Vaclav
authors.initials: V
authors.lastname: Horejsí
authors.forename: Ladislav
authors.initials: L
authors.lastname: Andera
mesh_terms: D000071443:12E7 Antigen; D048868:Adaptor Proteins, Signal Transducing; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015703:Antigens, CD / Q000096:biosynthesis; D000943:Antigens, Differentiation; D017209:Apoptosis; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D056970:Co-Repressor Proteins; D003432:Cross-Linking Reagents / Q000494:pharmacology; D018076:DNA, Complementary / Q000378:metabolism; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D019169:Jurkat Cells; D007700:Kinetics; D017493:Leukocyte Common Antigens / Q000096:biosynthesis; D051917:Leukosialin; D018832:Molecular Chaperones; D016328:NF-kappa B / Q000378:metabolism; D009687:Nuclear Proteins; D009841:Oligonucleotides / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000096:biosynthesis / Q000378:metabolism*; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
chemical_list: D000071443:12E7 Antigen; D048868:Adaptor Proteins, Signal Transducing; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; C061828:CD99 protein, human; D002352:Carrier Proteins; D015815:Cell Adhesion Molecules; D056970:Co-Repressor Proteins; D003432:Cross-Linking Reagents; C106985:DAXX protein, human; D018076:DNA, Complementary; C483616:ICAM3 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D051917:Leukosialin; D018832:Molecular Chaperones; D016328:NF-kappa B; D009687:Nuclear Proteins; D009841:Oligonucleotides; C465014:SPN protein, human; D012795:Sialoglycoproteins; D013778:Tetrazolium Salts; D013844:Thiazoles; D017493:Leukocyte Common Antigens; C022616:thiazolyl blue