Oxidized LDLs inhibit TLR-induced IL-10 production by monocytes: a new aspect of pathogen-accelerated atherosclerosis

Inflammation. 2012 Aug;35(4):1567-84. doi: 10.1007/s10753-012-9472-3.

Abstract

It is widely accepted that oxidized low-density lipoproteins and local infections or endotoxins in circulation contribute to chronic inflammatory process at all stages of atherosclerosis. The hallmark cells of atherosclerotic lesions-monocytes and macrophages-are able to detect and integrate complex signals derived from lipoproteins and pathogens, and respond with a spectrum of immunoregulatory cytokines. In this study, we show strong inhibitory effect of oxLDLs on anti-inflammatory interleukin-10 production by monocytes responding to TLR2 and TLR4 ligands. In contrast, pro-inflammatory tumor necrosis factor secretion was even slightly increased, when stimulated with lipopolysaccharide from Porphyromonas gingivalis-an oral pathogen associated with atherosclerosis. The oxLDLs modulatory activity may be explained by altered recognition of pathogen-associated molecular patterns, which involves serum proteins, particularly vitronectin. We also suggest an interaction between vitronectin receptor, CD11b, and TLR2. The presented data support a novel pathway for pathogen-accelerated atherosclerosis, which relies on oxidized low-density lipoprotein-mediated modulation of anti-inflammatory response to TLR ligands.

MeSH terms

  • Atherosclerosis / metabolism
  • CD11b Antigen / metabolism
  • CD36 Antigens / metabolism
  • Cells, Cultured
  • Humans
  • Inflammation / immunology
  • Integrin alphaVbeta3 / metabolism
  • Interleukin-10 / biosynthesis*
  • Ligands
  • Lipopolysaccharide Receptors / metabolism
  • Lipopolysaccharides / immunology
  • Lipoproteins, LDL / metabolism*
  • Lipoproteins, LDL / pharmacology
  • Macrophages / metabolism
  • Monocytes / drug effects
  • Monocytes / metabolism*
  • Porphyromonas gingivalis / immunology
  • Toll-Like Receptor 2 / immunology*
  • Toll-Like Receptor 2 / metabolism
  • Toll-Like Receptor 4 / immunology*
  • Toll-Like Receptor 4 / metabolism
  • Vitronectin / metabolism

Substances

  • CD11b Antigen
  • CD36 Antigens
  • Integrin alphaVbeta3
  • Ligands
  • Lipopolysaccharide Receptors
  • Lipopolysaccharides
  • Lipoproteins, LDL
  • TLR2 protein, human
  • TLR4 protein, human
  • Toll-Like Receptor 2
  • Toll-Like Receptor 4
  • Vitronectin
  • lipopolysaccharide A
  • oxidized low density lipoprotein
  • Interleukin-10