Regulation of HIV-1 transcription in activated monocyte macrophages.
DNA-binding and functional assays examined the role played by NF-IL6 in regulation of HIV-1 transcription in human monocyte/macrophages (U937 cells), stimulated with LPS+PMA. When incubated with nuclear extracts from stimulated cells, a region (-189/-147), containing the major NF-IL6-binding sequence and the USF site, interacted selectively with USF1 and USF2. Anti-C/EBPbeta reacted poorly with the complexes produced with the wild-type probe. In contrast, complex formation with NF-IL6 was clearly evident in experiments analyzing a probe containing an insertion in the USF site. In functional assays, increasing concentrations of a decoy against NF-IL6 reduced gene expression from the LTR of the wild-type HIV-1 variant, supporting a critical role for NF-IL6 in regulation of HIV-1 transcription in stimulated monocyte/macrophages. The decoy also reduced gene expression from a deletion construct lacking NF-IL6-binding sequences. The results implied that in LPS+PMA-stimulated monocyte/macrophages, the endogenous NF-IL6 could act via a site-independent pathway in upregulation of HIV-1 transcription. Analysis of a short DNA segment, containing the -189/-147 region, suggested functional interactions of NF-IL6 and USF. In activated cells exogenous NF-IL6 enhanced dramatically gene expression through a short DNA segment containing the NF-kappaB sites, supporting functional interactions of NF-IL6 and NF-kappaB.
Yang
Yingmei
Y
Department of Chemistry, Purdue University, 1393 Brown Building, West Lafayette, IN 47907-1393, USA.
Tesmer
Valerie M
VM
Bina
Minou
M
D022782:CCAAT-Enhancer-Binding Protein-beta / Q000494:pharmacology; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation; D008264:Macrophages / Q000821:virology*; D009000:Monocytes / Q000821:virology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014158:Transcription, Genetic; D020298:U937 Cells
D022782:CCAAT-Enhancer-Binding Protein-beta; D008070:Lipopolysaccharides; D013755:Tetradecanoylphorbol Acetate