Project description:<p>Despite the astonishing progress in treating chronic hepatitis C virus (HCV) infection with direct-acting antiviral agents, liver fibrosis remains a major health concern in HCV infected patients, in particular due to the treatment cost and insufficient HCV screening in many countries. Only a fraction of patients with chronic HCV infection develop liver fibrosis. While there is evidence that host genetic factors are involved in the development of liver fibrosis, the common variants identified so far, in particular by genome-wide association studies, were found to have limited effects.</p> <p>Here, we conducted an exome association study in 88 highly selected HCV-infected patients with and without fibrosis. A strategy focusing on TGF-β pathway genes revealed an enrichment in rare variants of the endoglin gene (<i>ENG</i>) in fibrosis patients. Replication studies in additional cohorts (617 patients) identified one specific <i>ENG</i> variant, Thr5Met, with an overall odds ratio for fibrosis development in carriers of 3.04 (1.39-6.69). Our results suggest that endoglin, a key player in TGF-β signaling, is involved in HCV-related liver fibrogenesis.</p>
Project description:Despite advances in antiviral therapy, molecular drivers of Hepatitis C Virus (HCV)-related liver disease remain poorly characterised. Chronic infection with HCV genotypes (1 and 3) differ in presentation of liver steatosis and virological response to therapies, both to interferon and direct acting antivirals. Using whole transcriptome microarrays, we analysed gene expression profiles of liver tissue obtained from individuals infected with either HCV G1 or G3 in progressive and advanced liver disease and identified key altered cellular pathways.
Project description:CD8+ T cells play a central role in antiviral control. We used single cell RNA sequencing (scRNA-seq) to analyze the differences of HCV-specific CD8+ T cells isolated from subjects that are chronically infected by HCV, individuals that spontaneously resolved an acute HCV infection, and chronic HCV patients in treatment with direct-acting antiviral (DAA). We also profiled non-HCV virus-specific cells (CMV and FLU) to analyze the impact of HCV infection on the adaptive immune response.
Project description:Although treatment of chronic hepatitis C virus (HCV) infection with direct acting antivirals (DAAs) results in high rates of cure, liver fibrosis does not resolve immediately after HCV eradication. Resolution of fibrosis occurs in some, but not all patients, after HCV cure, and hepatic decompensation and hepatocellular carcinoma can still occur in patients with pre-existing cirrhosis. We hypothesized that evaluation of the host liver proteome in the context of HCV treatment would provide insight into how inflammatory and fibrinogenic pathways change upon HCV eradication. We evaluated the whole liver proteome and phosphoproteome using paired liver biopsies from 8 HCV-infected patients collected before or immediately after treatment with DAAs in clinical trials. We identify interferon stimulated proteins as the predominant pathways that decrease with HCV treatment, which is consistent with previous analyses of the liver transcriptome during DAA therapy. While there was no change in the proteome of pathways associated with liver fibrosis, we identified a decrease in the phosphoproteome signature for ERK1/ERK2 as a result of HCV treatment. Conclusion: There is a reduction in the endogenous interferon-mediated antiviral response and alterations in the phosphoproteome that may precede resolution of fibrosis in the liver immediately after treatment of HCV with DAAs.
Project description:Hepatitis C virus (HCV) chronically infects 170 million people worldwide and is a leading cause of liver-related mortality due to hepatocellular carcinoma and cirrhosis1. Standard-of-care treatment is shifting from interferon-alpha (IFNM-NM-1)-based to IFNM-NM-1-free directly acting antiviral (DAA) regimens, which demonstrate improved efficacy and tolerability in clinical trials2,3. Virologic relapse after completion of DAA therapy is a common cause of treatment failure, although mechanisms are unclear2,3. We conducted a clinical trial using the DAA sofosbuvir with ribavirin (SOF/RBV)4, and report here detailed mRNA expression analysis of pre- and end-of-treatment (EOT) liver biopsies and blood samples. On-treatment viral clearance was accompanied by rapid down-regulation of interferon-stimulated genes (ISGs) in liver and blood. Analysis of paired liver biopsies from patients who achieved a sustained virologic response (SVR) revealed that viral clearance was accompanied by decreased expression of ISGs, IFNG, and IFNLs, but increased expression of IFNA2. Patients who achieved SVR had higher expression of a hepatic type-I interferon gene signature in unpaired EOT liver biopsies than patients who later relapsed. Together, these results support a model whereby restoration of type-I intrahepatic interferon signaling at the EOT is associated with sustained hepatic HCV suppression and prevention of relapse upon withdrawal of SOF/RBV. Sustained Virologic Response for Chronic Hepatitis C Patients Treated with Sofosbuvir and Ribavirin
Project description:Chronic hepatitis C virus infection (HCV) causes liver inflammation and fibrosis, leading to development of severe liver disease, such as cirrhosis or hepatocellular carcinoma (HCC). Approval of direct acting antiviral (DAA) drug combinations has revolutionized chronic HCV therapy, with virus eradication in >98% of the treated patients. The efficacy of these treatments is such that it is formally possible for cured patients to carry formerly infected cells that display irreversible transcriptional alterations directly caused by chronic HCV Infection. Combining differential transcriptomes from two different persistent infection models, we observed a major reversion of infection-related transcripts after complete infection elimination. However, a small number of transcripts were abnormally expressed in formerly infected cells. Comparison of the results obtained in proliferating and growth-arrested cell culture models suggest that permanent transcriptional alterations may be established by several mechanisms. Interestingly, some of these alterations were also observed in the liver biopsies of virologically cured patients. Overall, our data suggest a direct and permanent impact of persistent HCV infection on the host cell transcriptome even after virus elimination, possibly contributing to development of HCC.