An increase in p50/p65 NF-kB binding to the HIV-1 LTR is not sufficient to increase viral expression in the primary human astrocyte.
Human astrocytes can be infected with HIV-1 both in vivo and in vitro. The amount of HIV-1 p24 structural protein production is low in comparison to that of the macrophage. Several weeks following infection or transfection, however, cocultivation with uninfected lymphocytes or stimulation with the cytokines TNF-alpha and IL 1-beta will increase viral production from this cell type. In the present study we demonstrate that phorbol 12-myristate 13-acetate (PMA) also increases HIV-1 p24 production from the primary human astrocyte. Using electrophoretic mobility shift assay (EMSA) in combination with supershift studies using specific antibodies, we demonstrate that PMA, like TNF-alpha, increases the p50/p65 form of NF-kB. Furthermore we demonstrate that the protein kinase inhibitor H7 inhibits PMA- and TNF-alpha-associated increases in HIV-1 expression at a time when it has little to no inhibitory effect on the associated increases in p50/p65 NF-kB. Thus, unless p50/p65 NF-kB or its binding is affected by H7 in a manner that cannot be resolved by EMSA, an increase in this form of NF-kB is not always sufficient to increase HIV-1 expression from the astrocyte.
Laboratory of Molecular Medicine and Neuroscience, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
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D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D001253:Astrocytes / Q000821:virology*; D001483:Base Sequence; D002478:Cells, Cultured; D005333:Fetus; D015967:Gene Expression Regulation, Viral / Q000187:drug effects / Q000502:physiology*; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D010879:Piperazines / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D007546:Isoquinolines; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D013755:Tetradecanoylphorbol Acetate