Abstract
It has been proposed that prolactin (PRL) is a lympho-hemopoietic growth and differentiation factor. We show here by Western blotting that PRL-receptors (PRL-R) are expressed in normal rat bone marrow and spleen cells. We also show that PRL stimulates the phosphorylation of the PRL-R-associated Janus tyrosine kinase (JAK)-2 in rat bone marrow and spleen cells. This leads to the activation and subsequent binding of signal transducer and activator of transcription (Stat) 5b to an interferon regulatory factor-1 (IRF-1) gamma activation sequence (GAS) as visualized by electromobility shift assay. As shown after reverse transcription of mRNA by polymerase chain reaction, PRL, at physiological concentrations (0.01 microg/ml), stimulates the expression of the IRF-1 gene in these normal cells. PRL could thus affect several aspects of the immune response.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Bone Marrow Cells / immunology
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Cell Line
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Cells, Cultured
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DNA-Binding Proteins / genetics*
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DNA-Binding Proteins / metabolism
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Hematopoietic Stem Cells / cytology
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Hematopoietic Stem Cells / drug effects
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Hematopoietic Stem Cells / immunology*
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Interferon Regulatory Factor-1
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Interferon-gamma / physiology
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Lymphocytes / cytology
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Lymphocytes / drug effects
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Lymphocytes / immunology*
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Milk Proteins*
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Phosphoproteins / genetics*
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Prolactin / pharmacology
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Prolactin / physiology*
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RNA, Messenger / genetics
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Rats
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Receptors, Prolactin / genetics*
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STAT5 Transcription Factor
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Spleen / immunology
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Thymus Gland / immunology
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Trans-Activators / metabolism
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Transcription Factors / genetics
Substances
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DNA-Binding Proteins
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Interferon Regulatory Factor-1
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Irf1 protein, rat
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Milk Proteins
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Phosphoproteins
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RNA, Messenger
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Receptors, Prolactin
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STAT5 Transcription Factor
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Trans-Activators
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Transcription Factors
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Interferon-gamma
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Prolactin