In addition, NKp30 and NKp44 expression levels were also up-regulated on peripheral NK cells in IA patients versus IT subjects. TRAIL was preferentially expressed on CD56bright NK subsets with respect to CD56dim NK subsets (data not shown), and TRAIL expression levels on both hepatic and peripheral CD56bright NK subsets click here was up-regulated in IA patients versus IT and HC subjects. FasL expression on total NK cells was similar among the three cohorts. Thus, activation receptor–expressing NK cells were preferentially enriched in the livers of IA patients. We then analyzed the expression levels
of the human leukocyte antigen DR (HLA-DR), CD38, and CD69 activation markers on NK cells in these subjects. As shown in Fig. 2A,B, both hepatic and peripheral NK cells from IA patients expressed significantly higher levels of HLA-DR, CD38, and CD69 than those observed in IT and HC subjects. The mean fluorescence intensities (MFIs) of HLA-DR, CD38, and CD69 expression on hepatic and peripheral NK cells from IA patients were also increased in comparison with those from IT and HC subjects (data not shown).
These data suggest that NK cells are activated in vivo in IA patients. We then evaluated the ability of NK cells to produce IFN-γ and CD107a in response to K562 cells and PMA in combination with ionomycin. As shown in Fig. 3A,B, PMA/ionomycin stimulation induced higher levels of hepatic NK cell degranulation (CD107a expression) and IFN-γ production in IA patients and IT carriers versus HCs. Upon K562 stimulation, the expression of 上海皓元医药股份有限公司 CD107a (but not the expression of IFN-γ) was increased in Sirolimus cost both hepatic and peripheral NK cells in IA patients in comparison with IT subjects. In addition, basal levels of CD107a were detected on hepatic NK cells from IA patients but not on those from IT and HC subjects (Supporting Information Fig. 4A,B). Next, we performed the redirected cytotoxicity assay through NK activation receptor binding to P815 target cells via the immunoglobulin
Fcγ receptor (Fig. 4A) and found that anti-ALS (anti-CD16) and mixed anti-NCR antibodies (anti-NKp30, anti-NKp44, and anti-NKp46) induced more CD107a degranulation in both LILs and PBMCs from IA patients in comparison with HC subjects; meanwhile, IFN-γ production was increased only in response to anti-ALS antibodies and not in response to anti-NCR monoclonal antibodies in IA patients (Fig. 4A,B). Further analysis revealed that the anti-NKp30 antibody treatment induced NK cells to produce more CD107a and IFN-γ than the treatment with the anti-NKp44 and NKp46 antibodies; this suggests that NKp30 is primarily responsible for the NCR-associated cytolytic activity in IA patients (Supporting Information Fig. 5). We further found that NK cells from IA patients induced higher levels of K562 lysis than those from IT and HC subjects at the 30:1 E:T ratio (Fig. 5A,B).