Project description:B-cell receptor (BCR) signaling is essential for the development of B-cells and plays a critical role in B-cell neoplasia. Increasing evidence indicates an association between chronic hepatitis C virus (HCV) infection and B-cell lymphoma, however, the mechanisms by which HCV causes B-cell lymphoproliferative disorder are still unclear. Herein, we demonstrate the expression of HCV viral proteins in B-cells of HCV-infected patients and show that HCV up-regulates BCR signaling in human primary B-cells. HCV nonstructural protein NS3/4A interacts with CHK2 and down-regulates its activity, modulating HuR posttranscriptional regulation of a network of target mRNAs associated with B-cell lymphoproliferative disorders. Interestingly, the BCR signaling pathway was found to have the largest number of transcripts with increased association with HuR and was up-regulated by NS3/4A. Our study reveals a previously unidentified role of NS3/4A in regulation of host BCR signaling during HCV infection, contributing to a better understanding of the molecular mechanisms underlying HCV-associated B-cell lymphoproliferative disorders.
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:Hepatic complications of HCV infection, including fibrosis and cirrhosis are accelerated in HIV-infected individuals. Although liver biopsy remains the gold standard for staging HCV-associated liver disease, this test can result in serious complications and is subject to sampling error. These challenges have prompted a search for non-invasive methods for liver fibrosis staging. To this end, we compared serum proteome profiles at different stages of fibrosis in HIV/HCV co- and HCV mono-infected patients using SELDI-TOF MS.
Project description:A total of 117 HIV-1 infected patients were analyzed. These individuals were categorized in three different groups according to their infectious status for HCV: A) HIV+/HCV+ group, (n=45) patients with HIV infection and active HCV-chronic infection naïve to any HCV treatment (positive PCR and positive HCV antibodies); B) HIV+/HCV- group, (n=36) patients who had been exposed to HCV but experienced spontaneous viral clearance during the first 6 months after HCV infection (negative PCR and positive HCV antibodies); C) HIV+ group, (n=36) HIV+ mono-infected patients that had never been infected with HCV (negative PCR, negative HCV antibody and no previous HCV treatment). Briefely, peripheral venous blood samples were collected in EDTA tubes, and PBMCs were isolated within the first 4 hours after extraction.Total RNA including miRNAs were isolated from PBMCs with the miRNeasy Mini kit (Qiagen). Quality and integrity were evaluated by the Bioanalyzer 2100 with Agilent RNA 6000 Nano kit (Agilent). Only those samples with RIN > 7.5 were sequenced. Small RNA library synthesis and sequencing were performed at Centre for Genomic Regulation (CRG) at Barcelona (Spain). Small RNA libraries were constructed with Illumina’s TruSeq Small RNA kit v.4 (Illumina) and 50nts (1x50) were sequenced in an Illumina HiSeq2500, with a single read approach.
Project description:The impact of chronic hepatic infection on antigen non-specific immune cells, especially in association with liver fibrosis severity, remains poorly described. We previously reported lasting hyperfunction of bulk peripheral blood CD8 T cells in HCV-infected individuals with cirrhosis. RNA sequencing of blood CD8 T cells from HCV-infected individuals with minimal (Metavir F0-1, Fibroscan liver stiffness ≤ 7.0 kPa) or advanced fibrosis or cirrhosis (F4 ≥ 12.5 kPa), before and after direct-acting antiviral therapy, was performed. Principal component analyses determined robust differences in 362 genes expressed by CD8 T cells from HCV-infected individuals with minimal or advanced fibrosis and data suggests this remains relatively stable after viral clearance. Gene ontology analyses identified differential gene expression related to cellular metabolism, including upregulated phospholipase, phosphatidyl-choline/inositol activity and second-messenger-mediated signaling, while genes in pathways associated with nuclear processes, RNA transport and cytoskeletal dynamics were reduced. Gene Set Enrichment Analysis identified decreased expression of genes regulated by the cMyc and E2F transcription factors in cirrhotics, compared to the minimal fibrosis group, as well as reduced expression of genes linked to oxidative phosphorylation, mTOR signaling, and more. Upregulated gene sets in cirrhotics included IFN-α, -γ, TGF-β response genes, apoptosis, and apical surface pathways, among others. The Hedgehog (Hh) signaling pathway was the top featured gene set upregulated in cirrhotics, wherein hallmark genes GLI1 and PTCH1 ranked highly. This analysis of bulk CD8 T cell gene expression in chronic HCV infection suggests considerable reprogramming of the CD8 T cell pool in liver cirrhosis. Increased Hh signaling in cirrhosis may contribute to generalized CD8 T cell hyperfunction observed in chronic HCV infection. Understanding the lasting nature of immune cell dysfunction may help mitigate remaining clinical challenges after HCV clearance and more generally, improve long term outcomes for individuals with severe liver disease.
Project description:This study characterizes the effects of chronic Hepatitis C virus (HCV) infection on gene expression by analyzing blood samples from 10 treatment-naive HCV patients and 6 healthy volunteers. Differential expression analysis of microarray data from peripheral blood mononuclear cells (PBMCs) identified a 136 gene signature, including 66 genes elevated in infected individuals. Most of the up-regulated genes were associated with interferon (IFN) activity (including members of the OAS and MX families, ISG15 and IRF7), suggesting an ongoing immune response. This HCV signature was also found to be consistently enriched in many other viral infection and vaccination datasets. Validation of these genes was carried out using a second cohort composed of 5 HCV patients and 5 healthy volunteers, confirming the up-regulation of the IFN signature. In summary, this is the first study to directly compare blood transcriptional profiles from HCV patients with healthy controls. The results show that chronic HCV infection has a pronounced effect on gene expression in PBMCs of infected individuals, and significantly elevates the expression of a subset of interferon-stimulated genes.
Project description:This study characterizes the effects of chronic Hepatitis C virus (HCV) infection on gene expression by analyzing blood samples from 10 treatment-naive HCV patients and 6 healthy volunteers. Differential expression analysis of microarray data from peripheral blood mononuclear cells (PBMCs) identified a 136 gene signature, including 66 genes elevated in infected individuals. Most of the up-regulated genes were associated with interferon (IFN) activity (including members of the OAS and MX families, ISG15 and IRF7), suggesting an ongoing immune response. This HCV signature was also found to be consistently enriched in many other viral infection and vaccination datasets. Validation of these genes was carried out using a second cohort composed of 5 HCV patients and 5 healthy volunteers, confirming the up-regulation of the IFN signature. In summary, this is the first study to directly compare blood transcriptional profiles from HCV patients with healthy controls. The results show that chronic HCV infection has a pronounced effect on gene expression in PBMCs of infected individuals, and significantly elevates the expression of a subset of interferon-stimulated genes.
Project description:Hepatitis C virus (HCV) remains a significant public health threat as new 1.75 million HCV infections emerged worldwide. The majority of these infections become persistently infected, while around 30 % spontaneously eliminate the virus. Clinical factors for viral clarification are related to HCV interaction with host immune system, but little is known about the consequences after HCV spontaneous resolution. These individuals are difficult to recruit and study as acute infection is usually asymptomatic, and they will not be identified unless it progress to chronic infection. The study of peripheral blood mononuclear cells (PBMCs) of these patients is crucial, as PBMCs are one of the main HCV extrahepatic reservoirs, and its transcriptional profile provide us information of innate and adaptive immune response against HCV infection. Our research shows novel insight on molecular consequences of spontaneous resolution after an acute HCV infection. 96 Individuals with different HCV exposure status were recruited: spontaneous resolved, chronic infected and healthy controls; and the microRNA profile of their PBMCs were analyzed. Our results indicate similar disruption of miRNA expression on HCV chronic patients and those who spontaneously clarified the infection, compared to control patients. The disrupted miRNAs formed a signature of 21 miRNAs that mainly regulate lipid metabolism. This is the first report showing miRNA profile similarities between chronic HCV patients and spontaneous resolved individuals. Thus, our results suggest that HCV infection promotes molecular alterations in PBMCs that will last longer after HCV spontaneous eradication. This evidences open up new prospects in the management of individuals who spontaneously clarified infection, as they should be monitored and followed to dismiss future HCV-related complications, such us liver diseases complications. The identified miRNA signature could be used as biomarker to monitor HCV fingerprint on HCV-exposed patients.
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)
Project description:Purpose: This study unravel the mechanisms that link viral infection and cancer Methods:Human HCC cell line and HCC liver FFPE samples from HCC patients from three etiology groups- HBV, HCV infection, or neither were taken to explore their genomic DNA in two aspects: The HCC genomic mutations within the exons of 224 candidate genes, frequently mutated in HCC, using SureSelect™ Target Enrichment System kit and the transient response of liver cells to HCV infection, in genome wide histone modifications and gene expression, as demonstrated by ChIP-Seq and RNA-Seq. Results:Mutational signature was explored by high-resolution targeted sequencing that detected low-frequency passenger mutations in 64 HCC samples from three etiology groups – HBV, HCV, or other. We identified novel distinct etiology-dependent regional mutations signatures. To explore the link between genomic signature and genome wide chromatin organization we studied the epigenetic changes occur following HCV infection. We demonstrated that HCV infection induces epigenetic changes that persist as "epigenetic signature" following virus eradication and reprogram host gene expression. High mutation rate associated with HCV etiology correlated with HCV-induced changes in epigenetic markers leading to closed chromatin. Conclusions:We present a new link between cancer causing mutagenesis, and increase in liver cancer predisposition in chronic HCV-infected individuals. The sequential events begin with HCV-specific epigenetic signature that in turn dictates a unique HCV-specific somatic mutational profile in HCC