Abstract
The changes in the cytoplasmic free calcium concentrations (Cai) were investigated in human T (Jurkat) lymphoblastoid cells, loaded with the calcium-sensitive fluorescent dye Indo-1. A rapid increase in Cai could be evoked by monoclonal antibodies (mAb) directed against the CD3 antigen, as well as by the mitogenic lectin concanavalin A (conA). The protein kinase C (pKC) activators TPA and DiC8 did not increase Cai, but the addition of any of these two compounds prior to mAb eliminated the mAb-induced calcium signal. In contrast, the calcium signal evoked by ConA was not blocked by TPA or DiC8. These results suggest that the CD3-dependent calcium signal is selectively down-regulated by the activation of pKC.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Antigens, Differentiation, T-Lymphocyte / physiology*
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Calcium / pharmacology*
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Cell Line
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Depression, Chemical
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Diglycerides / pharmacology*
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Enzyme Activation / drug effects
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Glycerides / pharmacology*
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Humans
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Lymphocyte Activation / drug effects*
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Phorbol 12,13-Dibutyrate / pharmacology*
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Protein Kinase C / physiology*
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Receptors, Antigen, T-Cell / analysis
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Signal Transduction / drug effects*
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T-Lymphocytes / drug effects*
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Tetradecanoylphorbol Acetate / pharmacology*
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Tumor Cells, Cultured / drug effects
Substances
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Antigens, Differentiation, T-Lymphocyte
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Diglycerides
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Glycerides
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Receptors, Antigen, T-Cell
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1,2-dioctanoylglycerol
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Phorbol 12,13-Dibutyrate
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Protein Kinase C
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Tetradecanoylphorbol Acetate
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Calcium