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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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12E7 Antigen
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Adaptor Proteins, Signal Transducing
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Antibodies, Monoclonal / metabolism
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Antigens, CD / biosynthesis
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Antigens, Differentiation*
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Apoptosis*
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Blotting, Western
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Carrier Proteins / metabolism*
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Cell Adhesion
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Cell Adhesion Molecules / biosynthesis
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Cell Division
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Cell Line
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Cell Nucleus / metabolism
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Co-Repressor Proteins
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Cross-Linking Reagents / pharmacology
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DNA, Complementary / metabolism
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Down-Regulation
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Electrophoresis, Polyacrylamide Gel
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Flow Cytometry
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Hematopoietic Stem Cells / metabolism
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Humans
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Intracellular Signaling Peptides and Proteins*
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Jurkat Cells
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Kinetics
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Leukocyte Common Antigens / biosynthesis
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Leukosialin
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Molecular Chaperones
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NF-kappa B / metabolism
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Nuclear Proteins*
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Oligonucleotides / metabolism
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Plasmids / metabolism
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Protein Binding
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Protein Transport
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Reverse Transcriptase Polymerase Chain Reaction
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Sialoglycoproteins / biosynthesis
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Sialoglycoproteins / metabolism*
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Tetrazolium Salts / pharmacology
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Thiazoles / pharmacology
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Time Factors
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Transcription, Genetic*
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Two-Hybrid System Techniques
Substances
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12E7 Antigen
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Adaptor Proteins, Signal Transducing
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Antibodies, Monoclonal
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Antigens, CD
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Antigens, Differentiation
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CD99 protein, human
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Carrier Proteins
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Cell Adhesion Molecules
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Co-Repressor Proteins
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Cross-Linking Reagents
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DAXX protein, human
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DNA, Complementary
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ICAM3 protein, human
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Intracellular Signaling Peptides and Proteins
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Leukosialin
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Molecular Chaperones
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NF-kappa B
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Nuclear Proteins
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Oligonucleotides
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SPN protein, human
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Sialoglycoproteins
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Tetrazolium Salts
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Thiazoles
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Leukocyte Common Antigens
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thiazolyl blue