A TLR4/MD2 fusion protein inhibits LPS-induced pro-inflammatory signaling in hepatic stellate cells

Biochem Biophys Res Commun. 2008 Oct 17;375(2):210-4. doi: 10.1016/j.bbrc.2008.07.150. Epub 2008 Aug 9.

Abstract

Activated hepatic stellate cells (HSCs) play a key role in hepatic fibrogenesis. In injured liver they are the main extracellular matrix protein producing cell type and further perpetuate hepatic injury by secretion of pro-inflammatory mediators. Since LPS-mediated signaling through toll-like receptor 4 (TLR4) has been identified as key fibrogenic signal in HSCs we aimed to test TLR4 as potential target of therapy via ligand-binding soluble receptors. Incubation of human HSCs with a fusion protein between the extracellular domain of TLR4 and MD2 which binds LPS inhibited LPS-induced NFkappaB and JNK activation. TLR4/MD2 abolished LPS-induced secretion of IL-6, IL-8, MCP1, and RANTES in HSCs. In addition, TLR4/MD2 fused to human IgG-Fc neutralized LPS activity. Since TLR4 mutant mice are resistant to liver fibrosis, the TLR4/MD2 soluble receptor might represent a new therapeutic molecule for liver fibrogenesis in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Chemokines / antagonists & inhibitors
  • Chemokines / biosynthesis
  • Humans
  • Immunoglobulin Fc Fragments / genetics
  • Immunoglobulin Fc Fragments / therapeutic use
  • Immunoglobulin G / genetics
  • Immunoglobulin G / therapeutic use
  • Lipopolysaccharides / antagonists & inhibitors*
  • Lipopolysaccharides / immunology
  • Liver Cirrhosis / drug therapy*
  • Liver Cirrhosis / immunology
  • Lymphocyte Antigen 96 / genetics
  • Lymphocyte Antigen 96 / therapeutic use*
  • MAP Kinase Kinase 4 / metabolism
  • Mice
  • NF-kappa B / metabolism
  • Protein Structure, Tertiary / genetics
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / therapeutic use*
  • Signal Transduction
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / therapeutic use*

Substances

  • Chemokines
  • Immunoglobulin Fc Fragments
  • Immunoglobulin G
  • Lipopolysaccharides
  • Lymphocyte Antigen 96
  • NF-kappa B
  • Recombinant Fusion Proteins
  • Toll-Like Receptor 4
  • MAP Kinase Kinase 4