NADPH oxidase NOX2 mediates TLR2/6-dependent release of GM-CSF from endothelial cells

FASEB J. 2017 Jun;31(6):2612-2624. doi: 10.1096/fj.201600729R. Epub 2017 Mar 8.


NADPH oxidase-generated reactive oxygen species (ROS) from immune cells are well known to be important for pathogen killing in response to TLR ligands. Here, we investigated a new aspect of NADPH oxidase in the TLR2/6-induced release of the immunologically relevant GM-CSF by endothelial cells. Stimulation of human endothelial cells with TLR2/6 agonist, MALP-2 (macrophage-activating lipopeptide of 2 kDa), induced NADPH oxidase activation and ROS formation. Inhibition by ROS scavengers and NADPH oxidase inhibitors blocked MALP-2-induced GM-CSF release. NADPH oxidase activators or ROS donors alone did not result in GM-CSF secretion; however, additional superoxide supply augmented MALP-2-induced GM-CSF secretion and restored GM-CSF levels after NADPH oxidase inhibition. MALP-2-dependent NF-ĸB activation was suppressed by NADPH oxidase inhibition, and inhibition of NF-κB completely blunted MALP-2-induced GM-CSF release. Vascular explants from mice that were deficient for the NADPH oxidase subunit p47 phox showed diminished intimal superoxide production and GM-CSF release after ex vivo stimulation with MALP-2. Moreover, an increase in circulating progenitor cells after MALP-2 injection was completely abolished in p47phox-knockout mice. Finally, MALP-2 stimulation increased mRNA expression of the major subunit NADPH oxidase, (Nox)2, in endothelial cells, and Nox2 inhibition prevented MALP-2-induced GM-CSF release. Our findings identify a Nox2-containing NADPH oxidase as a crucial regulator of the immunologic important growth factor GM-CSF after TLR2/6 stimulation in endothelial cells.-Schuett, J., Schuett, H., Oberoi, R., Koch, A.-K., Pretzer, S., Luchtefeld, M., Schieffer, B., Grote, K. NADPH oxidase NOX2 mediates TLR2/6-dependent release of GM-CSF from endothelial cells.

Keywords: endothelial cell biology; immune factors; innate immunity; pattern recognition receptors; reactive oxygen species.

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Animals
  • Cell Survival
  • Cells, Cultured
  • DNA Helicases
  • Gene Expression Regulation
  • Granulocyte-Macrophage Colony-Stimulating Factor / genetics
  • Granulocyte-Macrophage Colony-Stimulating Factor / metabolism*
  • Lipopeptides / pharmacology
  • Male
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • NADPH Oxidase 2
  • NADPH Oxidases / genetics
  • NADPH Oxidases / metabolism*
  • NF-kappa B
  • Phosphorylation
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 2 / metabolism*
  • Toll-Like Receptor 6 / genetics
  • Toll-Like Receptor 6 / metabolism*


  • Lipopeptides
  • Membrane Glycoproteins
  • NF-kappa B
  • TLR2 protein, human
  • TLR6 protein, human
  • Tlr2 protein, mouse
  • Tlr6 protein, mouse
  • Toll-Like Receptor 2
  • Toll-Like Receptor 6
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • macrophage stimulatory lipopeptide 2
  • CYBB protein, human
  • Cybb protein, mouse
  • NADPH Oxidase 2
  • NADPH Oxidases
  • ATPases Associated with Diverse Cellular Activities
  • DNA Helicases
  • RUVBL2 protein, mouse