Abstract |
Dendritic cells (DCs) sense virus via toll-like receptors (TLR) or retinoic acid inducible gene-I (RIG-I) and evoke a cascade of immune reactions. In myeloid DC (MDC) from hepatitis C virus (HCV)-infected patients, the levels of TLR/RIG-I-mediated IFN-beta or TNF-alfa induction are lower than those in uninfected donors, suggesting that their signal transduction in MDC is impaired. Dendritic cells in HCV infection are unresponsive to interferon (IFN)-alfa, thus failing to enhance MHC class-I related chain A/B and subsequent NK cell activation. Alternatively, NK cells from the patients down-regulate DC in the presence of HLA-E-expressing hepatocytes by secreting IL-10 and TGF-beta1. Such functional alteration of NK cells in HCV infection is ascribed to the enhanced expression of NKG2A/CD94. Activated NKT cells from the patients produce higher levels of IL-13 but comparable IFN-gamma with those from controls, showing their bias to Th2-type. In pegylated IFN-alfa/ ribavirin therapy for chronic hepatitis C, improved DC function is related with successful HCV eradication. In conclusion, cross-talks among DCs and innate lymphocytes are critical in shaping immune response against HCV, either spontaneously or therapeutically.
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Authors | Tatsuya Kanto |
Journal | Frontiers in bioscience : a journal and virtual library
(Front Biosci)
Vol. 13
Pg. 6183-92
(May 01 2008)
ISSN: 1093-9946 [Print] United States |
PMID | 18508652
(Publication Type: Journal Article, Review)
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Chemical References |
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Topics |
- Dendritic Cells
(classification, immunology)
- Hepatitis C
(immunology)
- Hepatitis, Viral, Human
(immunology)
- Humans
- Immunity, Innate
- Killer Cells, Natural
(immunology)
- Liver
(immunology, virology)
- Lymphocyte Subsets
(immunology)
- T-Lymphocytes
(immunology)
- Toll-Like Receptors
(physiology)
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