Inhibition of Apoptosis in a Human Pre-B–Cell Line by CD23 Is Mediated Via a Novel Receptor
| Autor: | Lindsey J. White, William Cushley, Bradford W. Ozanne, Jean-Pierre Aubry, Jean-Yves Bonnefoy, Pierre Graber |
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| Rok vydání: | 1997 |
| Předmět: |
medicine.medical_treatment
Immunology Cell CD23 hemic and immune systems Cell Biology Hematology Biology Biochemistry Cell biology Cytokine medicine.anatomical_structure immune system diseases Cell culture hemic and lymphatic diseases medicine Progenitor cell Receptor Autocrine signalling A431 cells |
| Zdroj: | Blood. 90:234-243 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood.v90.1.234 |
| Popis: | Human CD23 is a 45-kD type II membrane glycoprotein, which functions as a low-affinity receptor for IgE and as a ligand for the CD21 and CD11b/CD11c differentiation antigens. CD23 is released from the surface of cells as soluble fragments, and a 25-kD species of soluble CD23 (sCD23) appears to act as a multifunctional cytokine. In this report, sCD23 is shown to sustain the growth of low cell density cultures of a human pre-B–acute lymphocytic leukemia cell line, SMS-SB: no other cytokine tested was able to induce this effect. Flow cytometric analysis indicates that sCD23 acts to prevent apoptosis of SMS-SB cells. SMS-SB cells cultured at low cell density possess low levels of bcl-2 protein. Addition of sCD23 to cells at low cell density maintained bcl-2 expression at levels equivalent to those observed in SMS-SB cells cultured at higher cell densities. No CD23 mRNA was found in SMS-SB cells, ruling out an autocrine function for CD23 in this cell line model. Although SMS-SB cells do not express the known receptors for CD23, namely CD21, CD11b-CD18, or CD11c-CD18, the cells specifically bind CD23-containing liposomes, but not glycophorin-containing liposomes. Binding of CD23-containing liposomes is inhibited by anti-CD23 but not by anti-CD21 or anti-CD11b/c monoclonal antibodies. The data show that sCD23 prevents apoptosis of the SMS-SB cell line by acting through a novel receptor. |
| Databáze: | OpenAIRE |
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