Interferon-gamma and polyunsaturated fatty acids increase the binding of lipopolysaccharide to macrophages

Int J Exp Pathol. 1994 Oct;75(5):363-8.

Abstract

We have previously shown that interferon-gamma (IFN-gamma) increases the polyunsaturated fatty acid content of membrane phospholipids in cells that were sensitive to endotoxin. In this study, IFN-gamma was found to stimulate the binding of endotoxin to the murine macrophage cell line J774.2 and the human monocyte cell line U937. Interferon-gamma-activated J774.2 cells showed a 66% increase in fluoresceine isothiocyanate (FITC) labelled LPS binding (P < 0.0005 vs control cells) and a 49% increase in tritium labelled LPS binding (P < 0.0001 vs control cells). Interferon-gamma also induced a 35% increase in binding of FITC-LPS in U937 cells (P < 0.0001 vs control cells). In contrast, pretreatment of J774.2 cells with interferon-beta (IFN-beta) had no effect on binding of FITC-LPS. Preincubation with exogenously supplied polyunsaturated fatty acids, linoleic and arachidonic acids, resulted in increases of 74% and 69% in FITC-LPS binding, respectively (both P < 0.0005 vs control cells). On the other hand, pretreatment with the saturated fatty acid, palmitic acid, had no effect on FITC-LPS binding. We propose that IFN-gamma-induced changes in the membrane phospholipid fatty acid composition of macrophage-like cells influence the binding of endotoxin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arachidonic Acid / pharmacology
  • Dose-Response Relationship, Drug
  • Escherichia coli
  • Fatty Acids, Unsaturated / pharmacology*
  • Fluorescein-5-isothiocyanate
  • Humans
  • Interferon-gamma / pharmacology*
  • Linoleic Acids / pharmacology
  • Lipopolysaccharides / metabolism*
  • Macrophages / metabolism*
  • Mice
  • Recombinant Proteins
  • Tumor Cells, Cultured

Substances

  • Fatty Acids, Unsaturated
  • Linoleic Acids
  • Lipopolysaccharides
  • Recombinant Proteins
  • Arachidonic Acid
  • Interferon-gamma
  • Fluorescein-5-isothiocyanate