Role of intracellular calcium concentration and protein kinase C activation in IFN-gamma stimulation of U937 cells
| Autor: | J B, Klein, T M, Schepers, W L, Dean, G, Sonnenfeld, K R, McLeish |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Ionomycin
Macrophages Receptors IgG Antigens Differentiation Myelomonocytic Macrophage-1 Antigen Biological Transport HLA-DR Antigens Inositol 1 4 5-Trisphosphate Receptors Fc Isoquinolines Antigens Differentiation Piperazines Cell Compartmentation Cell Line Receptors Complement Enzyme Activation Interferon-gamma 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine Gallic Acid Antigens Surface Humans Tetradecanoylphorbol Acetate Calcium Protein Kinase C Signal Transduction |
| Zdroj: | Journal of immunology (Baltimore, Md. : 1950). 144(11) |
| ISSN: | 0022-1767 |
| Popis: | IFN-gamma enhances many monocyte functions, including oxidative metabolism and Ag presentation. IFN-gamma has been reported to increase the intracellular concentration of calcium ([Ca2+]i) and modulate protein kinase C activity in murine macrophages, but the signal transduction pathways induced by IFN-gamma in human cells and their functional significance are poorly understood. Our study examined the hypothesis that an increases in [Ca2+]i and protein kinase C activation are required for functional responses to IFN-gamma. The U937 cell line was used as a model of an IFN-gamma responsive cell. IFN-gamma caused a rapid and concentration-dependent increase in [Ca2+]i, which was partly inhibited by calcium-free medium, diltiazem, and TMB-8. IFN-gamma induced a fourfold increase in the concentration of inositol 1,4,5-trisphosphate. Induction of HLA-DR, Fc gamma R, CR3, and Mo3e Ag expression by IFN-gamma was blocked by concentrations of TMB-8 that inhibited an increase in [Ca2+]i, but not by protein kinase C inhibition by H-7 or inhibition of calmodulin with W-7. Ionomycin did not enhance Ag expression and PMA induced the expression of only the Mo3e Ag. We conclude that IFN-gamma induces antigenic expression on human U937 cells by a mechanism dependent on, but not limited to, an increase in intracellular calcium, which is likely due to inositol 1,4,5-trisphosphate generation. |
| Databáze: | OpenAIRE |
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