Abstract:
:Hepatitis C virus (HCV) has the ability to persist in the majority of infected people. Strong, multispecific and sustained T-cell response is correlated with viral clearance. The mechanisms of chronicity by HCV are unclear. HCV could restrain the immune system and establish chronic infection by modulating dendritic cell (DC) function, T-cell function or both. DC dysfunction has been postulated to be either due to direct HCV infection or by the presence of HCV proteins. In this report, for the first time, we have examined whether soluble HCV proteins can impair DC function or directly inhibit T-cell responses in the cells obtained from healthy uninfected people. Our studies revealed that different HCV proteins used distinct mechanisms to down-regulate DC functions. Individual HCV proteins, Core, NS3, NS4, NS5 as well as fused Polyprotein (Core-NS3-NS4) were found to impair functions of both immature DCs and mature DCs by regulating the expression of co-stimulatory and antigen presentation molecules, strikingly reducing IL-12 secretion, inducing the expression of FasL to mediate apoptosis, interfering with allo-stimulatory capacity, inhibiting toll-like receptor signaling and inhibiting nuclear translocation of NFkappaB in DCs. Interestingly, HCV proteins did not directly inhibit T-cell proliferation. Our findings clearly demonstrate that HCV proteins impair T-cell responses indirectly by inhibiting DCs that could result in a sub-optimal cellular immune response allowing for persistent HCV infections. These studies delineate important mechanisms by which initial DC dysfunction can establish contributing to chronicity. Our data are in agreement with earlier observations that DCs are impaired in HCV infected people.
journal_name
Int Immunoljournal_title
International immunologyauthors
Krishnadas DK,Ahn JS,Han J,Kumar R,Agrawal Bdoi
10.1093/intimm/dxq033subject
Has Abstractpub_date
2010-06-01 00:00:00pages
491-502issue
6eissn
0953-8178issn
1460-2377pii
dxq033journal_volume
22pub_type
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journal_title:International immunology
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journal_title:International immunology
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更新日期:2019-10-16 00:00:00
abstract::Ig are multifunctional molecules with distinct properties assigned to individual domains. To assess the importance of IgM domain assembly in B cell development we generated two transgenic mouse lines with truncated muH chains by homologous integration of the neomycin resistance gene (neo(r)) into exons C(mu)1 and C(mu...
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pub_type: 杂志文章
doi:10.1093/intimm/13.12.1489
更新日期:2001-12-01 00:00:00
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journal_title:International immunology
pub_type: 杂志文章
doi:10.1093/intimm/9.5.645
更新日期:1997-05-01 00:00:00
abstract::IL-18 is a proinflammatory cytokine that plays an important role in NK cell activation and T(h)1 response. IL-18 has a structural homology to IL-1, particularly IL-1beta. IL-18R, composed of IL-1R-related protein (IL-18Ralpha) and IL-1R accessory protein-like (IL-18Rbeta), belongs to the IL-1R family. Furthermore, IL-...
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pub_type: 杂志文章
doi:10.1093/intimm/12.2.151
更新日期:2000-02-01 00:00:00
abstract::Recent studies have suggested that Fas-mediated apoptosis is involved in the pathogenesis of intestinal injury. In this study, we determined the role of Fas/Fas ligand (FasL) interactions in different T cell compartments using a murine model of small intestinal injury. An intraperitoneal injection of 145-2C11 (anti-CD...
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pub_type: 杂志文章
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更新日期:2005-05-01 00:00:00
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journal_title:International immunology
pub_type: 杂志文章
doi:10.1093/intimm/dxp077
更新日期:2009-10-01 00:00:00
abstract::IgE plus antigen-stimulated mast cells degranulate, synthesize leukotrienes and secrete cytokines. According to the coalescence model this process is initiated in specific membrane compartments termed rafts. There, enhanced levels of glycosphingolipids and cholesterol stabilize the interaction of FcepsilonRI and Lyn, ...
journal_title:International immunology
pub_type: 杂志文章
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更新日期:2003-10-01 00:00:00
abstract::Novel biomarkers of rheumatoid arthritis (RA), in addition to antibodies against cyclic citrullinated peptides, are required. Metabolome analysis is a promising approach to identify metabolite biomarkers for clinical diagnosis. We adopted a comprehensive nontargeted metabolomics approach combining capillary electropho...
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pub_type: 杂志文章
doi:10.1093/intimm/dxaa059
更新日期:2020-08-31 00:00:00
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journal_title:International immunology
pub_type: 杂志文章
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abstract::Autoimmune gastritis is a CD4+ T cell-mediated disease induced in genetically susceptible mice by thymectomy on the third day after birth. Previous linkage analysis indicated that Gasa1 and Gasa2, the major susceptibility loci for gastritis, are located on mouse chromosome 4. Here we verified these linkage data by sho...
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journal_title:International immunology
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abstract::Naturally arising CD25(+)CD4(+) regulatory T (T(R)) cells can be exploited to establish immunologic tolerance to non-self antigens. In vivo exposure of CD25(+)CD4(+) T cells from normal naive mice to alloantigen in a T cell-deficient environment elicited spontaneous expansion of alloantigen-specific CD25(+)CD4(+) T(R)...
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pub_type: 杂志文章
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journal_title:International immunology
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abstract::Although CD4(+) T cells form a major subset of TCRalphabeta T cells, only a small number of TCRgammadelta T cells express CD4. Factors contributing to the down-regulation of CD4(+) TCRgammadelta T cells have not been identified. The CD5 molecule is expressed on most TCRgammadelta T cells in the spleen, whereas only a ...
journal_title:International immunology
pub_type: 杂志文章
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更新日期:2003-01-01 00:00:00
abstract::Dendritic cells (DC) are highly potent activators of the immune response. The precise mechanisms that give rise to the DC phenotype are not known. To investigate the mechanisms that contribute to the generation of the DC phenotype, precursor DC were freshly isolated from human blood and allowed to mature in vitro. The...
journal_title:International immunology
pub_type: 杂志文章
doi:10.1093/intimm/10.11.1713
更新日期:1998-11-01 00:00:00