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.
Original language | English |
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Pages (from-to) | 2605-15 |
Number of pages | 11 |
Journal | Molecular immunology |
Volume | 44 |
Issue number | 10 |
DOIs | |
Publication status | Published - Apr 2007 |
Keywords
- Animals
- Antigen Presentation
- Antigens, Helminth/immunology
- Cytokines/metabolism
- Dendritic Cells/drug effects
- 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