In:
The Journal of Immunology, The American Association of Immunologists, Vol. 191, No. 11 ( 2013-12-01), p. 5574-5582
Abstract:
The “liver tolerance effect” has been attributed to a unique potential of liver-resident nonprofessional APCs including hepatocytes (HCs) to suppress T cell responses. The exact molecular mechanism of T cell suppression by liver APCs is still largely unknown. In mice, IL-10–dependent T cell suppression is observed after Th1-mediated hepatitis induced by Con A. In this study, we show that HCs, particularly those from regenerating livers of Con A–pretreated mice, induced a regulatory phenotype in naive CD4+ T cells in vitro. Using reporter mice, we observed that these T regulatory cells released substantial amounts of IL-10, produced IFN-γ, failed to express Foxp3, but suppressed proliferation of responder T cells upon restimulation with anti-CD3 mAb. Hence, these regulatory cells feature a similar phenotype as the recently described IL-10–producing Th1 cells, which are generated upon activation of Notch signaling. Indeed, inhibition of γ-secretase and a disintegrin and metalloproteinase 17 but not a disintegrin and metalloproteinase 10, respectively, which blocked Notch activation, prevented IL-10 secretion. HCs from Con A–pretreated mice showed enhanced expression of the Notch ligand Jagged1 and significantly increased receptor density of Notch1 on CD4+ T cells. However, HCs from Con A–pretreated IFN regulatory factor 1−/− mice, which cannot respond to IFN-γ, as well as those from IFN-γ−/− mice failed to augment IL-10 production by CD4+ T cells. In conclusion, it seems that HCs fine-tune liver inflammation by upregulation of Jagged1 and activation of Notch signaling in Th1 cells. This mechanism might be of particular importance in the regenerating liver subsequent to Th1-mediated hepatitis.
Type of Medium:
Online Resource
ISSN:
0022-1767
,
1550-6606
DOI:
10.4049/jimmunol.1300826
Language:
English
Publisher:
The American Association of Immunologists
Publication Date:
2013
detail.hit.zdb_id:
1475085-5
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