Heterotrimeric G proteins physically associated with the lipopolysaccharide receptor CD14 modulate both in vivo and in vitro responses to lipopolysaccharide

J Clin Invest. 1998 Dec 1;102(11):2019-27. doi: 10.1172/JCI4317.

Abstract

Septic shock induced by lipopolysaccharide (LPS) triggering of cytokine production from monocytes/macrophages is a major cause of morbidity and mortality. The major monocyte/macrophage LPS receptor is the glycosylphosphatidylinositol (GPI)-anchored glycoprotein CD14. Here we demonstrate that CD14 coimmunoprecipitates with Gi/Go heterotrimeric G proteins. Furthermore, we demonstrate that heterotrimeric G proteins specifically regulate CD14-mediated, LPS-induced mitogen-activated protein kinase (MAPK) activation and cytokine production in normal human monocytes and cultured cells. We report here that a G protein binding peptide protects rats from LPS-induced mortality, suggesting a functional linkage between a GPI-anchored receptor and the intracellular signaling molecules with which it is physically associated.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Cell Line
  • GTP-Binding Proteins / isolation & purification
  • GTP-Binding Proteins / physiology*
  • Humans
  • Intercellular Signaling Peptides and Proteins
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism
  • Lipopolysaccharide Receptors / drug effects
  • Lipopolysaccharide Receptors / isolation & purification
  • Lipopolysaccharide Receptors / physiology*
  • Lipopolysaccharides / pharmacology*
  • Lipopolysaccharides / toxicity
  • Monocytes / drug effects
  • Monocytes / metabolism
  • Peptides
  • Rats
  • Recombinant Fusion Proteins / physiology
  • Shock, Septic / etiology
  • Shock, Septic / physiopathology*
  • Shock, Septic / prevention & control
  • Signal Transduction / drug effects*
  • Signal Transduction / physiology
  • Transfection
  • Virulence Factors, Bordetella / pharmacology
  • Wasp Venoms / pharmacology
  • Wasp Venoms / therapeutic use

Substances

  • Intercellular Signaling Peptides and Proteins
  • Lipopolysaccharide Receptors
  • Lipopolysaccharides
  • Peptides
  • Recombinant Fusion Proteins
  • Virulence Factors, Bordetella
  • Wasp Venoms
  • mastoparan
  • GTP-Binding Proteins