Vizantin inhibits endotoxin-mediated immune responses via the TLR 4/MD-2 complex

J Immunol. 2014 Nov 1;193(9):4507-14. doi: 10.4049/jimmunol.1401796. Epub 2014 Sep 26.


Vizantin has immunostimulating properties and anticancer activity. In this study, we investigated the molecular mechanism of immune activation by vizantin. THP-1 cells treated with small interfering RNA for TLR-4 abolished vizantin-induced macrophage activation processes such as chemokine release. In addition, compared with wild-type mice, the release of MIP-1β induced by vizantin in vivo was significantly decreased in TLR-4 knockout mice, but not in TLR-2 knockout mice. Vizantin induced the release of IL-8 when HEK293T cells were transiently cotransfected with TLR-4 and MD-2, but not when they were transfected with TLR-4 or MD-2 alone or with TLR-2 or TLR-2/MD-2. A dipyrromethene boron difluoride-conjugated vizantin colocalized with TLR-4/MD-2, but not with TLR-4 or MD-2 alone. A pull-down assay with vizantin-coated magnetic beads showed that vizantin bound to TLR-4/MD-2 in extracts from HEK293T cells expressing both TLR-4 and MD-2. Furthermore, vizantin blocked the LPS-induced release of TNF-α and IL-1β and inhibited death in mice. We also performed in silico docking simulation analysis of vizantin and MD-2 based on the structure of MD-2 complexed with the LPS antagonist E5564; the results suggested that vizantin could bind to the active pocket of MD-2. Our observations show that vizantin specifically binds to the TLR-4/MD-2 complex and that the vizantin receptor is identical to the LPS receptor. We conclude that vizantin could be an effective adjuvant and a therapeutic agent in the treatment of infectious diseases and the endotoxin shock caused by LPS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chemokine CCL4 / biosynthesis
  • Cytokines / biosynthesis
  • Endotoxins / immunology*
  • Gene Expression
  • Glycolipids / metabolism
  • Glycolipids / pharmacology*
  • HEK293 Cells
  • Humans
  • Immunity / drug effects*
  • Immunity / genetics
  • Inflammation Mediators / metabolism
  • Lipopolysaccharides / immunology
  • Lipopolysaccharides / pharmacology
  • Lymphocyte Antigen 96 / chemistry
  • Lymphocyte Antigen 96 / genetics
  • Lymphocyte Antigen 96 / metabolism*
  • Macrophages / chemistry
  • Macrophages / drug effects
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mice
  • Mice, Knockout
  • Models, Molecular
  • Protein Binding
  • Protein Conformation
  • Protein Transport
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / metabolism
  • Trehalose / analogs & derivatives*
  • Trehalose / metabolism
  • Trehalose / pharmacology


  • 6,6'-bis-O-(3-nonyldodecanoyl)-alpha,alpha'-trehalose
  • Chemokine CCL4
  • Cytokines
  • Endotoxins
  • Glycolipids
  • Inflammation Mediators
  • Lipopolysaccharides
  • Lymphocyte Antigen 96
  • Toll-Like Receptor 4
  • Trehalose