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Project description:Background and aimsChronic HCV infection is a leading etiologic driver of cirrhosis and ultimately HCC. Of the approximately 71 million individuals chronically infected with HCV, 10%-20% are expected to develop severe liver complications in their lifetime. Epigenetic mechanisms including DNA methylation and histone modifications become profoundly disrupted in disease processes including liver disease.Approach and resultsTo understand how HCV infection influences the epigenome and whether these events remain as "scars" following cure of chronic HCV infection, we mapped genome-wide DNA methylation, four key regulatory histone modifications (H3K4me3, H3K4me1, H3K27ac, and H3K27me3), and open chromatin in parental and HCV-infected immortalized hepatocytes and the Huh7.5 HCC cell line, along with DNA methylation and gene-expression analyses following elimination of HCV in these models through treatment with interferon-α (IFN-α) or a direct-acting antiviral (DAA). Our data demonstrate that HCV infection profoundly affects the epigenome (particularly enhancers); HCV shares epigenetic targets with interferon-α targets; and an overwhelming majority of epigenetic changes induced by HCV remain as "scars" on the epigenome following viral cure. Similar findings are observed in primary human patient samples cured of chronic HCV infection. Supplementation of IFN-α/DAA antiviral regimens with DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine synergizes in reverting aberrant DNA methylation induced by HCV. Finally, both HCV-infected and cured cells displayed a blunted immune response, demonstrating a functional effect of epigenetic scarring.ConclusionsIntegration of epigenetic and transcriptional data elucidate key gene deregulation events driven by HCV infection and how this may underpin the long-term elevated risk for HCC in patients cured of HCV due to epigenome scarring.
| S-EPMC9416882 | biostudies-literature
Project description:Background & aims: Chronic hepatitis C viral (HCV) infection is a leading etiologic driver of cirrhosis and ultimately hepatocellular carcinoma (HCC). Of the approximately ~71 million individuals chronically infected with HCV, 10-20% are expected to develop severe liver complications in their lifetime. Epigenetic mechanisms including DNA methylation and histone modifications become profoundly disrupted in disease processes including liver disease. Methods: To understand how HCV infection influences the epigenome and whether these events remain as ‘scars’ following cure of chronic HCV infection, we mapped genome-wide DNA methylation, four key regulatory histone modifications (H3K4me3, H3K4me1, H3K27ac, and H3K27me3) and open chromatin by ATAC-seq in parental and HCV-infected immortalized hepatocytes and the Huh7.5 HCC cell line, along with DNA methylation and gene expression analyses following elimination of HCV in these models through treatment with interferon-α or a direct-acting antiviral (DAA). Results: Our data demonstrate that HCV infection profoundly impacts the epigenome (particularly enhancers), HCV shares epigenetic targets with interferon-α targets, an overwhelming majority of epigenetic changes induced by HCV remain as ‘scars’ on the epigenome following cured infection, and similar findings are observed in primary human patient samples cured of chronic HCV infection. Supplementation of interferon-α/DAA antiviral regimens with DNA methyltransferase inhibitor 5-aza-2’deoxycytidine synergizes in reverting aberrant DNA methylation changes induced by HCV. Finally, both HCV-infected and cured cells displayed a blunted immune response, demonstrating a functional effect of epigenetic scarring. Conclusions: Integration of epigenetic and transcriptional data elucidates key gene deregulation events driven by HCV infection and how this may underpin the long-term elevated risk for HCC in patients cured of HCV due to epigenome scarring. Lay summary: Despite cure of hepatitis C viral (HCV) infection, patients remain at increased long-term risk for liver cancer. This study aimed to discover whether this effect was mediated through the epigenome. Using a novel cell culture system, we find that normal epigenetic marks and gene expression are disrupted by chronic HCV infection, and that these disrupted patterns are not restored following HCV cure. Moreover, the epigenetic disruptions caused by HCV are very similar to the natural interferon response that is typically key to clearing viral infections. Epigenetically disrupted pathways therefore contribute to suppression of innate immunity and increased risk for liver cancer in patients cured of HCV, but also reveal potential vulnerabilities that could be targeted pharmacologically.
2021-09-23 | GSE168185 | GEO
Project description:Hepatitis C virus scarring of the epigenome and creates targetable vulnerabilities following viral clearance
| PRJNA706410 | ENA
Project description:Interferon drives hepatitis C virus scarring of the epigenome and creates targetable vulnerabilities following viral clearance [array]
| PRJNA706413 | ENA
Project description:Background & aims: Chronic hepatitis C viral (HCV) infection is a leading etiologic driver of cirrhosis and ultimately hepatocellular carcinoma (HCC). Of the approximately ~71 million individuals chronically infected with HCV, 10-20% are expected to develop severe liver complications in their lifetime. Epigenetic mechanisms including DNA methylation and histone modifications become profoundly disrupted in disease processes including liver disease. Methods: To understand how HCV infection influences the epigenome and whether these events remain as ‘scars’ following cure of chronic HCV infection, we mapped genome-wide DNA methylation, four key regulatory histone modifications (H3K4me3, H3K4me1, H3K27ac, and H3K27me3) and open chromatin by ATAC-seq in parental and HCV-infected immortalized hepatocytes and the Huh7.5 HCC cell line, along with DNA methylation and gene expression analyses following elimination of HCV in these models through treatment with interferon-α or a direct-acting antiviral (DAA). Results: Our data demonstrate that HCV infection profoundly impacts the epigenome (particularly enhancers), HCV shares epigenetic targets with interferon-α targets, an overwhelming majority of epigenetic changes induced by HCV remain as ‘scars’ on the epigenome following cured infection, and similar findings are observed in primary human patient samples cured of chronic HCV infection. Supplementation of interferon-α/DAA antiviral regimens with DNA methyltransferase inhibitor 5-aza-2’deoxycytidine synergizes in reverting aberrant DNA methylation changes induced by HCV. Finally, both HCV-infected and cured cells displayed a blunted immune response, demonstrating a functional effect of epigenetic scarring. Conclusions: Integration of epigenetic and transcriptional data elucidates key gene deregulation events driven by HCV infection and how this may underpin the long-term elevated risk for HCC in patients cured of HCV due to epigenome scarring.
2021-09-23 | GSE168178 | GEO
Project description:Clearance of chronic hepatitis C virus infection leaves scars on the epigenome driven by an interferon response and creates targetable vulnerabilities [seq]
| PRJNA706404 | ENA
Project description:To define the early events that determine the outcome of acute hepatitis C virus (HCV) infection, we compared the course of viremia with the peripheral and intrahepatic T cell response and intrahepatic cytokine profile in six acutely infected chimpanzees. Three different outcomes were observed after peak viral titers were reached: sustained viral clearance, transient viral clearance followed by chronic infection, and chronic infection that persisted at initial peak titers. The results indicate that HCV spread outpaces the T cell response and that HCV rapidly induces but is not controlled by IFN-alphabeta; that viral clearance follows the entry and accumulation of HCV-specific IFN-gamma-producing T cells in the liver; and that it may not require the destruction of infected cells.
| S-EPMC137773 | biostudies-literature
Project description:Background and Aims: Viral clearance during acute hepatitis C virus (HCV) infection is associated with the induction of potent antiviral T-cell responses. Since dendritic cells (DC) are essential in the activation of primary T-cell responses our goal was to analyze gene expression in DC from patients during acute HCV infection. Methods: By using microarrays, gene expression was compared in resting and activated peripheral blood plasmacytoid (pDC) and myeloid (mDC) DC from acute HCV resolving patients (AR) and from those who become chronically infected (ANR), as well as in HCV chronically infected patients (CHR) and healthy seronegative individuals (CTRL). Results: For pDC, a high number of upregulated genes related to different functions and processes was found in AR patients, irrespective of DC stimulation. However, for mDC, most evident differences were detected after DC stimulation, again corresponding to upregulated genes in AR patients. Differences between AR and ANR were also observed when comparing their DC with those from CHR patients and CTRL individuals. Most differences corresponded to metabolism-associated genes, with upregulation in AR patients of genes belonging to pathways associated with DC activation and cytokine responses. Conclusion: Our results show that upregulation of relevant genes in DC during acute HCV infection may determine viral clearance, suggesting that dysfunctional DC may be responsible for the lack of efficient T-cell responses which lead to chronic HCV infection. Gene expression was compared in resting and activated peripheral blood plasmacytoid (pDC) and myeloid (mDC) DC from acute HCV resolving patients (AR) and from those who become chronically infected (ANR), as well as in HCV chronically infected patients (CHR) and healthy seronegative individuals (CTRL)
2016-07-29 | E-GEOD-65123 | biostudies-arrayexpress
Project description:AIM:To investigate the evaluation of hepatitis C virus (HCV) quasispecies in the envelope region and its relationship with the outcome of acute hepatitis C. METHODS:HCV quasispecies were characterized in specimens collected every 2-6 mo from a cohort of acutely HCV-infected subjects. We evaluated two individuals who spontaneously cleared viremia and three individuals with persistent viremia by cloning 33 1-kb amplicons that spanned E1 and the 5' half of E2, including hypervariable region 1 (HVR1). To assess the quasispecies complexity and to detect variants for sequencing, 33 cloned cDNAs representing each specimen were assessed by a combined method of analysis of a single-stranded conformational polymorphism and heteroduplex analysis. The rates of both synonymous and nonsynonymous substitutions for the E1, HVR1 and E2 regions outside HVR1 were analyzed. RESULTS:Serum samples collected from chronic phase of infection had higher quasispecies complexity than those collected from acute phase of infection in all individuals examined. The genetic diversity (genetic distance) within HVR1 was consistently higher than that in the complete E1 (0.0322+/-0.0068 vs -0.0020+/-0.0014, P<0.05) and E2 regions outside HVR1 (0.0322+/-0.0068 vs 0.0017+/-0.0011, P<0.05) in individuals with persistent viremia, but did not change markedly over time in those with clearance of viremia. For individuals with persistent viremia, the rate of nonsynonymous substitutions within the HVR1 region (2.76X10(-3)+/-1.51X10(-3)) predominated and gradually increased, as compared with that in the E1 and E2 regions outside HVR1 (0.23X10(-3)+/-0.15X10(-3), 0.50X10(-3)+/-0.10X10(-3)). By contrast, the rates of both nonsynonymous and synonymous substitutions for the E1 and E2 regions including HVR1 were consistently lower in individuals with clearance of viremia. CONCLUSION:HCV persistence is associated with a complexity quasispecies and positive selection of HVR1 by the host immune system.
| S-EPMC4305653 | biostudies-literature
Project description:Background and Aims: Viral clearance during acute hepatitis C virus (HCV) infection is associated with the induction of potent antiviral T-cell responses. Since dendritic cells (DC) are essential in the activation of primary T-cell responses our goal was to analyze gene expression in DC from patients during acute HCV infection. Methods: By using microarrays, gene expression was compared in resting and activated peripheral blood plasmacytoid (pDC) and myeloid (mDC) DC from acute HCV resolving patients (AR) and from those who become chronically infected (ANR), as well as in HCV chronically infected patients (CHR) and healthy seronegative individuals (CTRL). Results: For pDC, a high number of upregulated genes related to different functions and processes was found in AR patients, irrespective of DC stimulation. However, for mDC, most evident differences were detected after DC stimulation, again corresponding to upregulated genes in AR patients. Differences between AR and ANR were also observed when comparing their DC with those from CHR patients and CTRL individuals. Most differences corresponded to metabolism-associated genes, with upregulation in AR patients of genes belonging to pathways associated with DC activation and cytokine responses. Conclusion: Our results show that upregulation of relevant genes in DC during acute HCV infection may determine viral clearance, suggesting that dysfunctional DC may be responsible for the lack of efficient T-cell responses which lead to chronic HCV infection.
2016-07-29 | GSE65123 | GEO