Toll-like receptor 6 drives differentiation of tolerogenic dendritic cells and contributes to LcrV-mediated plague pathogenesis

Cell Host Microbe. 2008 Oct 16;4(4):350-61. doi: 10.1016/j.chom.2008.09.004.

Abstract

Educating dendritic cells (DC) to become tolerogenic DC, which promote regulatory IL-10 immune responses, represents an effective immune evasion strategy for pathogens. Yersinia pestis virulence factor LcrV is reported to induce IL-10 production via interaction with Toll-like receptor (TLR) 2. However, TLR2-/- mice are not protected against subcutaneous plague infection. Using complementary in vitro and in vivo approaches and LcrV as a model, we show that TLR6 associates with TLR2 to induce tolerogenic DC and regulatory type-1 T cells selectively secreting IL-10. In contrast, TLR1 heterodimerizes with TLR2 to promote proinflammatory IL-12p40 cytokine, producing DC and inflammatory T cell differentiation. LcrV specifically hijacks the TLR2/6 pathway to stimulate IL-10 production, which blocks host protective inflammatory responses. These results explain why TLR2 can mediate both pro- and anti-inflammatory responses and identify TLR6 as a distinct receptor driving regulatory IL-10 responses.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Bacterial / immunology*
  • Cell Differentiation*
  • Colony Count, Microbial
  • Dendritic Cells / immunology*
  • Immunologic Factors / pharmacology*
  • Interleukin-10 / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Plague / immunology*
  • Plague / microbiology
  • Pore Forming Cytotoxic Proteins / immunology*
  • Survival Analysis
  • T-Lymphocytes, Regulatory / immunology
  • Toll-Like Receptor 6 / immunology*
  • Virulence Factors / immunology*
  • Yersinia pestis / immunology*
  • Yersinia pestis / pathogenicity

Substances

  • Antigens, Bacterial
  • Immunologic Factors
  • LcrV protein, Yersinia
  • Pore Forming Cytotoxic Proteins
  • Toll-Like Receptor 6
  • Virulence Factors
  • Interleukin-10