Control by IFN-gamma and PGE2 of TNF alpha and IL-1 production by human monocytes

Immunology. 1989 Mar;66(3):376-83.

Abstract

There have been suggestions that the production of pro-inflammatory mediators by human monocytes in response to interferon-gamma (IFN-gamma) may be controlled by changes in prostaglandins. Therefore we investigated tumour necrosis factor alpha (TNF alpha) and interleukin-1 (IL-1) activities and prostaglandin E2 (PGE2) levels in the supernatants of highly purified human monocytes cultured for 18 hr with recombinant human IFN-gamma. IFN-gamma (100 U/ml) did not stimulate monocytes isolated by counter-current centrifugal elutriation for detectable TNF alpha or IL-1 activities, or PGE2 production. However, IFN-gamma synergistically enhanced lipopolysaccharide (LPS)-induced TNF alpha and IL-1 activities. In contrast, there was no consistent change in PGE2 levels upon addition of IFN-gamma to LPS-treated monocyte cultures. The TNF alpha and IL-1 activities induced by LPS and by LPS with IFN-gamma were reduced by PGE2, and stimulated by indomethacin. As reported previously for IL-1 activities, the regulation by cyclo-oxygenase products of TNF alpha activities reflected predominantly a control of the production of immunoreactive TNF alpha, rather than the measurement of TNF alpha bio-activity. However, the addition of indomethacin or PGE2 to monocyte cultures did not change the extent of IFN-gamma synergy with LPS for increased TNF alpha and IL-1 activities. The results of this study suggest that, despite control by cyclo-oxygenase products of TNF alpha and IL-1 production in human monocytes, IFN-gamma may enhance TNF alpha and IL-1 activities independently of this regulatory mechanism. These findings are contrary to those suggested for the regulation by prostanoids of IL-1 production by murine macrophages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cells, Cultured
  • Dinoprostone / metabolism
  • Dinoprostone / pharmacology*
  • Humans
  • Indomethacin / pharmacology
  • Interferon-gamma / pharmacology*
  • Interleukin-1 / biosynthesis*
  • Lipopolysaccharides / pharmacology
  • Monocytes / drug effects*
  • Monocytes / metabolism
  • Prostaglandin-Endoperoxide Synthases / physiology
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha / biosynthesis*

Substances

  • Interleukin-1
  • Lipopolysaccharides
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha
  • Interferon-gamma
  • Prostaglandin-Endoperoxide Synthases
  • Dinoprostone
  • Indomethacin