DC-SIGN ligation on dendritic cells results in ERK and PI3K activation and modulates cytokine production

Blood. 2006 May 15;107(10):3950-8. doi: 10.1182/blood-2005-03-1252. Epub 2006 Jan 24.

Abstract

The generation of pathogen-specific immune responses is dependent on the signaling capabilities of pathogen-recognition receptors. DC-SIGN is a C-type lectin that mediates capture and internalization of viral, bacterial, and fungal pathogens by myeloid dendritic cells. DC-SIGN-interacting pathogens are thought to modulate dendritic cell maturation by interfering with intracellular signaling from Toll-like receptor molecules. We report that engagement of DC-SIGN by specific antibodies does not promote dendritic cell maturation but induces ERK1/2 and Akt phosphorylation without concomitant p38MAPK activation. DC-SIGN ligation also triggers PLCgamma phosphorylation and transient increases in intracellular calcium in dendritic cells. In agreement with its signaling capabilities, a fraction of DC-SIGN molecules partitions within lipid raft-enriched membrane fractions both in DC-SIGN-transfected and dendritic cells. Moreover, DC-SIGN in dendritic cells coprecipitates with the tyrosine kinases Lyn and Syk. The relevance of the DC-SIGN-initiated signals was demonstrated in monocyte-derived dendritic cells, as DC-SIGN cross-linking synergizes with TNF-alpha for IL-10 release and enhances the production of LPS-induced IL-10. These results demonstrate that DC-SIGN-triggered intracellular signals modulate dendritic cell maturation. Since pathogens stimulate Th2 responses via preferential activation of ERK1/2, these results provide a molecular explanation for the ability of DC-SIGN-interacting pathogens to preferentially evoke Th2-type immune responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / blood
  • Antigens, CD / immunology
  • Calcium / physiology*
  • Calcium Signaling
  • Cell Adhesion Molecules / physiology*
  • Cell Line
  • Cross-Linking Reagents
  • Cytokines / biosynthesis*
  • Cytokines / blood
  • Dendritic Cells / immunology*
  • Enzyme Activation
  • Humans
  • Interleukin-10 / blood
  • Lectins, C-Type / physiology*
  • MAP Kinase Signaling System / physiology*
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Receptors, Cell Surface / physiology*

Substances

  • Antigens, CD
  • Cell Adhesion Molecules
  • Cross-Linking Reagents
  • Cytokines
  • DC-specific ICAM-3 grabbing nonintegrin
  • Lectins, C-Type
  • Receptors, Cell Surface
  • Interleukin-10
  • Phosphatidylinositol 3-Kinases
  • Calcium