Abstract
Signaling pathways for the antiviral and antiproliferative biological effects of type I interferons (IFN) are well established. In this report we demonstrate a novel signaling pathway for IFN-alpha, as it induced rapid phosphorylation of both PKB/Akt and its substrate forkhead. The PI3-kinase inhibitor LY294002 abolished these phosphorylations. PI3-kinase has been implicated in cell survival mediating its effect through the second messenger PIP3 and the subsequent activation of PKB/Akt. We could show that IFN-alpha inhibited spontaneous apoptosis of primary B-lymphocytes, in the absence of a mitogenic stimulus. This effect was inhibited by LY294002. Thus, our data suggests that IFN-alpha promotes survival of peripheral B-lymphocytes via the PI3-kinase-PKB/Akt pathway. In addition, IFN-alpha stimulation of anti-IgM activated cells resulted in downregulated expression of the cell cycle inhibitor p27/Kip1.
Copyright 2001 Academic Press.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Apoptosis / drug effects
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B-Lymphocytes / cytology*
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B-Lymphocytes / drug effects
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B-Lymphocytes / enzymology
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Cell Cycle Proteins / metabolism
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Cell Survival / drug effects
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Cells, Cultured
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Cyclin-Dependent Kinase Inhibitor p27
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DNA-Binding Proteins / metabolism
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Down-Regulation
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Enzyme Activation
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Forkhead Box Protein O1
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Forkhead Transcription Factors
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Humans
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Immunoglobulin M / immunology
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Interferon-alpha / pharmacology*
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Lymphocyte Activation
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Phosphatidylinositol 3-Kinases / physiology*
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Phosphorylation / drug effects
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Protein Serine-Threonine Kinases*
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Proto-Oncogene Proteins / metabolism
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Proto-Oncogene Proteins c-akt
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Transcription Factors / metabolism
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Tumor Suppressor Proteins*
Substances
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Cell Cycle Proteins
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DNA-Binding Proteins
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FOXO1 protein, human
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Forkhead Box Protein O1
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Forkhead Transcription Factors
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Immunoglobulin M
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Interferon-alpha
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Proto-Oncogene Proteins
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Transcription Factors
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Tumor Suppressor Proteins
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Cyclin-Dependent Kinase Inhibitor p27
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AKT1 protein, human
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Protein Serine-Threonine Kinases
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Proto-Oncogene Proteins c-akt