Schistosoma mansoni soluble egg antigens are internalized by human dendritic cells through multiple C-type lectins and suppress TLR-induced dendritic cell activation

Mol Immunol. 2007 Apr;44(10):2605-15. doi: 10.1016/j.molimm.2006.12.012. Epub 2007 Jan 22.

Abstract

In schistosomiasis, a parasitic disease caused by helminths, the parasite eggs induce a T helper 2 cell (T(H)2) response in the host. Here, the specific role of human monocyte-derived dendritic cells (DCs) in initiation and polarization of the egg-specific T cell responses was examined. We demonstrate that immature DCs (iDCs) pulsed with schistosome soluble egg antigens (SEA) do not show an increase in expression of co-stimulatory molecules or cytokines, indicating that no conventional maturation was induced. The ability of SEA to affect the Toll-like receptor (TLR) induced maturation of iDCs was examined by copulsing the DCs with SEA and TLR-ligands. SEA suppressed both the maturation of iDCs induced by poly-I:C and LPS, as indicated by a decrease in co-stimulatory molecule expression and production of IL-12, IL-6 and TNF-alpha. In addition, SEA suppressed T(H)1 responses induced by the poly-I:C-pulsed DCs, and skewed the LPS-induced mixed response towards a T(H)2 response. Immature DCs rapidly internalized SEA through the C-type lectins DC-SIGN, MGL and the mannose receptor and the antigens were targeted to MHC class II-positive lysosomal compartments. The internalization of SEA by multiple C-type lectins may be important to regulate the response of the iDCs to TLR-induced signals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigen Presentation
  • Antigens, Helminth / immunology*
  • Antigens, Helminth / pharmacology
  • Cytokines / metabolism
  • Dendritic Cells / drug effects
  • Dendritic Cells / immunology*
  • Histocompatibility Antigens Class II / immunology
  • Humans
  • Lectins, C-Type / immunology*
  • Ligands
  • Lipopolysaccharides / pharmacology
  • Lysosomal-Associated Membrane Protein 1 / metabolism
  • Ovum / immunology
  • Poly I-C / pharmacology
  • Schistosoma mansoni / immunology*
  • T-Lymphocytes / immunology
  • Toll-Like Receptors / immunology*

Substances

  • Antigens, Helminth
  • Cytokines
  • Histocompatibility Antigens Class II
  • Lectins, C-Type
  • Ligands
  • Lipopolysaccharides
  • Lysosomal-Associated Membrane Protein 1
  • Toll-Like Receptors
  • Poly I-C