Project description:NK cells are believed to contribute to the control of hepatitis C virus infection and pathogenesis of liver disease. Standard treatment of both acute and chronic hepatitis C is based on the administration of interferon alpha, however, the effects of type I interferons on human NK cells have not been studied in the context of hepatitis C. We therefore first performed a microarray screen for genes differentially regulated in human NK cells after stimulation of PBMC with recombinant interferon alpha-2b. One of the genes upregulated was TRAIL which was confirmed in vitro on the protein level. Keywords: Interferon alpha; human NK cells; stimulation for 6 hours; cells sorted after stimulation of whole PBMC
Project description:NK cells are believed to contribute to the control of hepatitis C virus infection and pathogenesis of liver disease. Standard treatment of both acute and chronic hepatitis C is based on the administration of interferon alpha, however, the effects of type I interferons on human NK cells have not been studied in the context of hepatitis C. We therefore first performed a microarray screen for genes differentially regulated in human NK cells after stimulation of PBMC with recombinant interferon alpha-2b. One of the genes upregulated was TRAIL which was confirmed in vitro on the protein level. Keywords: Interferon alpha; human NK cells; stimulation for 6 hours; cells sorted after stimulation of whole PBMC NK cells of PBMC of five healthy controls have been either isolated directly or after culturing for 6h in media containing 10% human AB serum supplemented with 1 and 100 ng/ml recombinant IFNa-2b. RNA of NK cells of the healthy controls was isolated and RNA was pooled for the hybridization.
Project description:Approximately 50% of patients with chronic hepatitis C (CHC) have a sustained virologic response (SVR) to treatment with pegylated interferon (pegINF)-α and ribavirin. Non-response to treatment is associated with constitutively increased expression of IFN-stimulated genes (ISGs) in the liver. Treatment of patients with acute hepatitis C (AHC) is more effective, with SVR rates >90%. We investigated mechanisms of the different responses of patients with CHC and AHC to pegIFN-α therapy. We analyzed IFN signaling and ISG expression in liver samples from patients with acute hepatitis C (AHC), patients with chronic hepatitis (CHC), and individuals without hepatitis C (controls) using microarray, immunohistochemical, and protein analyses. Findings were compared with those from primary human hepatocytes stimulated with IFN-α or IFN-γ, as reference sets. Expression levels of 100s of genes, primarily those regulated by IFN-γ, were altered in liver samples from patients with AHC compared with controls. Expression of IFN-γ–stimulated genes was induced in liver samples from patients with AHC, whereas expression of IFN-α–stimulated genes was induced in samples from patients with CHC. In an expression analysis of negative regulators of IFN-α signaling, we did not observe differences in expression of SOCS1 or SOCS3 between liver samples from patients with AHC and those with CHC. However, USP18 (another negative regulator of IFN-α signaling), was upregulated in liver samples of patients with CHC that did not respond to therapy, but not in AHC. In conclusion, differences in expression of ISGs might account for the greater response of patients with AHC, compared to those with CHC, to treatment with pegINF-α and ribavirin. Specifically, USP18 is upregulated in liver samples of patients with CHC that do not respond to therapy, but not in patients with AHC. (Interferon-γ Stimulated Genes, but not USP18, are Expressed in Livers of Patients with Acute Hepatitis C; Dill MT, Makowska Z et al, Gastroenterology 2012 (in press)) Primary human hepatocytes from 2 donors were analyzed. From each donor there are 5 samples: untreated cells, cells treated with interferon alpha (1000 IU/ml) for 6 and 24 hours and cells treated with interferon gamma (1000 IU/ml) for 6 and 24 hours.
Project description:Hepatitis C virus (HCV) infection is primarily treated with a pegylated interferon alpha based therapy, a regime that induces antiviral effects through the upregulation of many interferon-stimulated genes (ISGs). Whilst a number of anti-HCV ISGs have previously been identified, others may also be involved. Micorarrays were used to validate the presence of ISGs within subtracted libraries generated using the related techniques of suppression subtractive hybridisation and mirror orientation selection, which had initally been impllemented to isolate clones of ISGs following the interferon-alpha treatment of Huh-7 cells. Microarray data was generated for both untreated and interferon-alpha treated Huh-7 cells. No replicates were performed, however the microarray data was verified via the use of non-parametric (spearman) correlation analysis with RT-PCR data that had been generated using the same Huh-7 cell total RNA samples as the microarray experiments earlier.
Project description:Hepatitis C virus (HCV) infection is primarily treated with a pegylated interferon alpha based therapy, a regime that induces antiviral effects through the upregulation of many interferon-stimulated genes (ISGs). Whilst a number of anti-HCV ISGs have previously been identified, others may also be involved. Micorarrays were used to validate the presence of ISGs within subtracted libraries generated using the related techniques of suppression subtractive hybridisation and mirror orientation selection, which had initally been impllemented to isolate clones of ISGs following the interferon-alpha treatment of Huh-7 cells.
Project description:All major types of interferon (IFN) efficiently inhibit hepatitis C virus (HCV) replication in vitro and in vivo. Remarkably, HCV replication is not sensitive to IFN? in the hepatoma cell line Huh6, despite an intact signaling pathway. We performed transcriptome analyses between Huh6 and Huh-7 to identify effector genes of the IFN? response and thereby identified the DExD/H box helicase DDX60L as a restriction factor of HCV replication. DDX60L and its homolog DDX60 were both induced upon viral infection and IFN treatment in primary human hepatocytes. However, exclusively DDX60L knockdown increased HCV replication in Huh-7 cells, and rescued HCV replication from type II IFN as well as type I and III IFN treatment, suggesting that DDX60L is an important effector protein of the innate immune response against HCV. DDX60L had no impact on replication of hepatitis A virus (HAV), but severely impaired production of lentiviral vectors, arguing for a potential antiretroviral activity. Detection of endogenous DDX60L protein turned out to be difficult due to instability. DDX60L knockdown did not alter interferon stimulated gene (ISG) induction after IFN treatment, suggesting that it is a direct effector of the innate immune response. It most likely inhibits viral RNA replication, since we found no impact of DDX60L on translation or stability of HCV subgenomic replicons, nor additional impact on entry and assembly of infectious virus. Similar to its homolog DDX60, DDX60L had a moderate impact on retinoic acid-inducible gene I (RIG-I)-dependent activation of innate immunity arguing for additional functions in the sensing of viral RNA. Gene Expression was compared between two cell lines, Huh6 and Huh7, under interferon-gamma or interferon-alpha treatment. We intended to identify genes that are more strongly upregulated in Huh-7 than in Huh6 in response to interferon treatment.