Lactoferrin suppresses the Epstein-Barr virus-induced inflammatory response by interfering with pattern recognition of TLR2 and TLR9

Lab Invest. 2014 Nov;94(11):1188-99. doi: 10.1038/labinvest.2014.105. Epub 2014 Jul 28.

Abstract

Epstein-Barr virus (EBV) infection contributes to tumorigenesis of various human malignancies including nasopharyngeal carcinoma (NPC). EBV triggers innate immune and inflammatory responses partly through Toll-like receptor (TLR) signaling. Lactoferrin (LF), with its anti-inflammatory properties, is an important component of the innate immune system. We previously reported that LF protects human B lymphocytes from EBV infection by its ability to bind to the EBV receptor CD21, but whether LF can suppress EBV-induced inflammation is unclear. Here, we report that LF reduced synthesis of IL-8 and monocyte chemoattractant protein-1 (MCP-1) induced by EBV in macrophages via its suppression of NF-κB activity. LF interacted with TLR2 and interfered with EBV-triggered TLR2-NF-κB activation. LF inhibited the ability of TLR9 to recognize dsDNA by binding to its co-receptor CD14, which blocked the interaction between CD14 and TLR9. EBV-induced inflammation was thus aggravated in the presence of CD14. In addition, LF expression levels were significantly downregulated in NPC specimens, and correlated inversely with IL-8 and MCP-1 expression. These findings suggest that LF may suppress the EBV-induced inflammatory response through interfering with the activation of TLR2 and TLR9.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemokine CCL2 / metabolism
  • Epstein-Barr Virus Infections / immunology
  • Female
  • HEK293 Cells
  • Herpesvirus 4, Human / immunology*
  • Host-Pathogen Interactions
  • Humans
  • Interleukin-8 / metabolism
  • Lactoferrin / physiology*
  • Lipopolysaccharide Receptors / metabolism
  • Macrophages / physiology*
  • Male
  • Middle Aged
  • NF-kappa B / metabolism
  • Toll-Like Receptor 2 / immunology*
  • Toll-Like Receptor 9 / immunology*
  • Up-Regulation

Substances

  • CCL2 protein, human
  • CXCL8 protein, human
  • Chemokine CCL2
  • Interleukin-8
  • Lipopolysaccharide Receptors
  • NF-kappa B
  • TLR2 protein, human
  • TLR9 protein, human
  • Toll-Like Receptor 2
  • Toll-Like Receptor 9
  • Lactoferrin