Internalization of Dectin-1 terminates induction of inflammatory responses

Eur J Immunol. 2009 Feb;39(2):507-13. doi: 10.1002/eji.200838687.

Abstract

Dectin-1 is a pattern-recognition receptor recognizing beta-(1,3)-glucans found on fungal cell walls. Dectin-1 plays an important role in immunity to fungi by mediating phagocytic clearance of fungal particles and inducing transcription of innate response genes. We show here that the two processes are linked and that Dectin-1 signalling for inflammation is attenuated by phagocytosis. Blocking Dectin-1 ligand-dependent internalization using either actin polymerization or dynamin inhibitors, large non-phagocytosable beta-glucan particles or poorly phagocytic cells leads in all cases to enhanced and sustained activation of downstream signalling pathways and culminates in production of high levels of pro-inflammatory cytokines. These findings establish the importance of phagocytosis not only in the clearance of pathogens, but also in the modulation of pattern-recognition receptor signalling and strongly suggest that internalization is the first step to attenuation of Dectin-1-mediated pro-inflammatory responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport / genetics
  • Adaptor Proteins, Vesicular Transport / immunology
  • Animals
  • Cytokines / immunology*
  • Immunity, Innate
  • Inflammation / immunology*
  • Lectins, C-Type
  • Membrane Proteins / genetics
  • Membrane Proteins / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mitogen-Activated Protein Kinase Kinases / immunology*
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Myeloid Differentiation Factor 88 / genetics
  • Myeloid Differentiation Factor 88 / immunology
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / immunology*
  • Phagocytosis / immunology*
  • Signal Transduction
  • beta-Glucans / immunology

Substances

  • Adaptor Proteins, Vesicular Transport
  • Cytokines
  • Lectins, C-Type
  • Membrane Proteins
  • Myd88 protein, mouse
  • Myeloid Differentiation Factor 88
  • Nerve Tissue Proteins
  • TICAM-1 protein, mouse
  • beta-Glucans
  • dectin 1
  • Mitogen-Activated Protein Kinase Kinases