Two forms of NF-kappa B1 (p105/p50) in murine macrophages: differential regulation by lipopolysaccharide, interleukin-2, and interferon-gamma.


Journal Article

In macrophages, nuclear factor kappa B (NF-kappa B) has been shown to transactivate the promoters of many cytokines, including tumor necrosis factor-alpha (TNF-alpha). We have used the -510 kappa B binding site from the murine TNF-alpha promoter to assay the induction of NF-kappa B in murine macrophages by various stimuli. A basal level of NF-kappa B activity in murine macrophages was detectable, and this activity was enhanced by treatment of these cells with lipopolysaccharide (LPS) or interleukin-2 (IL-2). Interferon-gamma (IFN-gamma), an important regulator of macrophage gene expression, significantly enhanced NF-kappa B activity and altered the apparent molecular weight of the NF-kappa B1-like proteins in LPS-stimulated and IL-2-stimulated murine macrophages. The NRD (NF-kappa B/Rel/Dorsal) complexes induced by LPS and IFN-gamma were further characterized by addition of antisera to electrophoretic mobility shift assay (EMSA) reaction mixtures. NF-kappa B1/p50 was a component of all complexes, whereas RelA/p65 was present in the IFN-gamma/LPS-stimulated activity. IFN-gamma priming or treatment with LPS for 19 h resulted in an upregulation of the larger species of NF-kappa B1/p50. In addition, regulation of the two pools of NF-kappa B1/p50 by IFN-gamma was confirmed by Western immunoblot analysis of cytosolic and nuclear extracts. This is the first demonstration of the presence of two pools of NF-kappa B1/p50 differentially regulated in response to cytokine activation of macrophages.

Full Text

Duke Authors

Cited Authors

  • Brown, MC; Tomaras, GD; Vincenti, MP; Taffet, SM

Published Date

  • May 1997

Published In

Volume / Issue

  • 17 / 5

Start / End Page

  • 295 - 306

PubMed ID

  • 9181468

Pubmed Central ID

  • 9181468

International Standard Serial Number (ISSN)

  • 1079-9907

Digital Object Identifier (DOI)

  • 10.1089/jir.1997.17.295


  • eng

Conference Location

  • United States