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Early changes in natural killer cell function indicate virologic response to interferon therapy for hepatitis C.

ABSTRACT: BACKGROUND & AIMS:Mathematical modeling of hepatitis C virus (HCV) kinetics indicated that cellular immune responses contribute to interferon (IFN)-induced clearance of HCV. We investigated a potential role of natural killer (NK) cells in this process. METHODS:Phenotype and function of blood and liver NK cells were studied during the first 12 weeks of treatment with pegylated IFN-alfa and ribavirin, the time period used to define the early virological response. RESULTS:Within hours of treatment initiation, NK cells of patients that had an early virological response increased expression of activating receptors NKG2D, NKp30, and CD16 and decreased expression of NKG2C and 2B4, along with inhibitory receptors SIGLEC7 and NKG2A, resulting in NK cell activation. NK cell cytotoxicity, measured by degranulation and tumor necrosis factor-related apoptosis-inducing ligand production, peaked after 24 hours (P<.01), concomitant with an increase in alanine aminotransferase levels (P<.05), whereas IFN-? production decreased within 6 hours and did not recover for more than 4 weeks (P<.05). NK cells from liver biopsies taken 6 hours after treatment initiation had increased numbers of cytotoxic CD16+NK cells (P<.05) and a trend toward increased production of tumor necrosis factor-related apoptosis-inducing ligand. Degranulation of peripheral blood NK cells correlated with treatment-induced, first-phase decreases in viral load (P<.05) and remained higher in early virological responders than in nonresponders for weeks. CONCLUSIONS:IFN activates NK cells early after treatment is initiated. Their cytotoxic function, in particular, is strongly induced, which correlates to virologic response. Therefore, NK cell activation indicates responsiveness to IFN-?-based treatment and suggests the involvement of the innate immune cells in viral clearance.

SUBMITTER: Ahlenstiel G

PROVIDER: S-EPMC3353552 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature

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Early changes in natural killer cell function indicate virologic response to interferon therapy for hepatitis C.

Ahlenstiel Golo G Edlich Birgit B Hogdal Leah J LJ Rotman Yaron Y Noureddin Mazen M Feld Jordan J JJ Holz Lauren E LE Titerence Rachel H RH Liang T Jake TJ Rehermann Barbara B

Gastroenterology 20110707 4

<h4>Background & aims</h4>Mathematical modeling of hepatitis C virus (HCV) kinetics indicated that cellular immune responses contribute to interferon (IFN)-induced clearance of HCV. We investigated a potential role of natural killer (NK) cells in this process.<h4>Methods</h4>Phenotype and function of blood and liver NK cells were studied during the first 12 weeks of treatment with pegylated IFN-alfa and ribavirin, the time period used to define the early virological response.<h4>Results</h4>With ...[more]

PMID: 21741920

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Project description:Background & aimsChronic hepatitis C virus infection activates an intrahepatic immune response, leading to increased expression of interferon (IFN)-stimulated genes and activation of natural killer (NK) cells-the most prevalent innate immune cell in the liver. We investigated whether the elimination of hepatitis C virus with direct-acting antiviral normalizes expression of IFN-stimulated genes and NK cell function.MethodsWe used multicolor flow cytometry to analyze NK cells from the liver and blood of 13 HCV-infected patients who did not respond to treatment with pegylated interferon and ribavirin. Samples were collected before and during IFN-free treatment with daclatasvir and asunaprevir and compared with samples from the blood of 13 healthy individuals (controls). Serum levels of chemokine C-X-C motif ligand (CXCL) 10 or CXCL11 were measured by enzyme-linked immunosorbent assay.ResultsBefore treatment, all patients had increased levels of CXCL10 or CXCL11 and a different NK cell phenotype from controls, characterized by increased expression of HLA-DR, NKp46, NKG2A, CD85j, signal transducer and activator of transcription 1 (STAT1), phosphorylated STAT1, and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). NK cells from patients also had increased degranulation and decreased production of IFNγ and tumor necrosis factor α compared with NK cells from controls. Nine patients had an end-of-treatment response (undetectable virus) and 4 had virologic breakthrough between weeks 4 and 12 of therapy. A rapid decrease in viremia and level of inflammatory cytokines in all patients was associated with decreased activation of intrahepatic and blood NK cells; it was followed by restoration of a normal NK cell phenotype and function by week 8 in patients with undetectable viremia. This normalized NK cell phenotype was maintained until week 24 (end of treatment).ConclusionsDirect-acting antiviral-mediated clearance of HCV is associated with loss of intrahepatic immune activation by IFNα, which is indicated by decreased levels of CXCL10 and CXCL11 and normalization of NK cell phenotype and function.

Project description:BackgroundTo investigate the changes of natural killer (NK) cell phenotype in the interferon alpha (IFN-α) treatment of chronic hepatitis B (CHB) and its relationship with clinical indicators.MethodsThe CHB patients who did not receive any antiviral treatment were set as initial treatment group and used pegylated interferon alpha (PEG-IFN α). Peripheral blood samples were collected at baseline, 4 weeks, and 12-24 weeks. For IFN-treated patients who entered the plateau were set as plateau group, and PEG-IFN α was discontinued and resumed after an interval of 12-24 weeks. Besides, we also enrolled some patients who had received oral drug for more than 6 months as oral drug group without follow up. Peripheral blood was collected during the plateau period, which was set as baseline, and after 12-24 weeks of intermittent treatment, and after 12-24 weeks of additional treatment with PEG-IFN α. The aim of the collection was to detect hepatitis B virus (HBV) virology, serology and biochemical indicators, and the NK cell related phenotype was detected by flow cytometry.ResultsIn the plateau group, subgroup of CD69+CD56dim was higher with statistical significance when comparing with the initial treatment group and oral drug group [10.49 (5.27, 19.07) vs 5.03 (3.67, 8.58), Z = -3.11, P = 0.002; 10.49 (5.27, 19.07) vs 4.04 (1.90, 7.26), Z = -5.30, P < 0.001)]. CD57+CD56dim was significantly lower than that in initial treatment group and oral drug group respectively [68.42±10.37 vs 55.85±12.87, t = 5.84, P < 0.001; 76.38±9.49 vs 55.85±12.87, t = -9.65, P < 0.001]. The CD56brightCD16- subgroup in the plateau group was higher with statistical significance compared with initial treatment group and oral drug group respectively [11.64 (6.05, 19.61) vs 3.58 (1.94, 5.60), Z = -6.35, P < 0.001; 11.64 (6.05, 19.61) vs 2.37 (1.70, 4.30), Z = -7.74, P < 0.001)]. CD57+CD56dim in the plateau group had a significant higher percentage than that at baseline after IFN discontinuation for 12-24 weeks (55.85±12.87 vs 65.95±12.94, t = -2.78, P = 0.011).ConclusionDuring the long-term treatment of IFN, the killer subgroup of NK cells is continuously depleted, leading to the differentiation of the regulatory subgroup into the killer subgroup. In the killing subgroup, although the number is continuously depleted, the activity of the subgroup is continuously increased. In the plateau phase, after stopping IFN for a period of time, the number of NK cell subsets would gradually recover, but was still lower than that in the initial treatment group.

Project description:Autoimmune hepatitis (AIH) is an immune-mediated liver disease currently treated by immunosuppressive medications with significant side effects. Thus, novel mechanistic treatments are greatly needed. We performed prospective deep immunophenotyping of blood immune cells in patients with acute AIH before and after corticosteroid therapy. Blood samples from 26 patients with acute AIH (United Kingdom-AIH Consortium) were phenotyped by flow cytometry at baseline and 4 months after starting corticosteroids. Pretreatment liver tissues were stained for forkhead box P3-positive (FOXP3POS) regulatory T cells (Tregs), clusters of differentiation (CD)56POS natural killer (NK) cells, and chemokine (C-X-C motif) ligand 10. Chemokine secretion by cultured primary hepatocyte and biliary epithelial cells was measured by enzyme-linked immunosorbent assay. Functional coculture assays with stimulated NK cells and Tregs were performed. CD161 ligand, lectin-like transcript-1 expression by intrahepatic immune cells was demonstrated with flow cytometry. Frequencies of NKbright cells declined with therapy (P < 0.001) and correlated with levels of alanine aminotransferase (P = 0.023). The Treg:NKbright ratio was lower pretreatment, and Tregs had an activated memory phenotype with high levels of CD39, cytotoxic T lymphocyte antigen 4, and FOXP3 but also high programmed death ligand 1, indicating exhaustion. Coculture experiments suggested the Tregs could not efficiently suppress interferon-γ secretion by NK cells. Both Tregs and NK cells had high expression of liver infiltration and T helper 17 plasticity-associated marker CD161 (P = 0.04). Pretreatment and CD161pos NK cells expressed high levels of perforin and granzyme B, consistent with an activated effector phenotype (P < 0.05). Lectin-like transcript 1, a ligand for CD161, is expressed on intrahepatic B cells, monocytes, and neutrophils. Conclusion: Activated effector NK cells, which correlate with biochemical measurements of hepatitis, and exhausted memory Tregs are increased in the blood of patients with treatment-naive AIH and decline with corticosteroid therapy. Inadequate regulation of NK cells by exhausted FOXP3pos Tregs may play a role in AIH pathogenesis and contribute to liver injury. (Hepatology Communications 2018;2:421-436).

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Early changes in natural killer cell function indicate virologic response to interferon therapy for hepatitis C.

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Early changes in natural killer cell function indicate virologic response to interferon therapy for hepatitis C.

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