The inflammasome components NLRP3 and ASC act in concert with IRGM to rearrange the Golgi during viral infections

AbstractHepatitis C virus (HCV) infection triggers Golgi fragmentation through the Golgi-resident protein immunity-related GTPase M (IRGM). Here, we report the role of NLRP3 and ASC, two inflammasome components, in the initial events leading to this fragmentation. We show that ASC resides at the Golgi with IRGM at homeostasis. Upon infection, ASC dissociates from both IRGM and Golgi and associates with HCV-induced NLRP3. NLRP3 silencing inhibits Golgi fragmentation. ASC silencing disrupts the Golgi structure in both control and infected cells and reduces the localization of IRGM at the Golgi. Silencing IRGM cannot totally restore the Golgi structure. These data highlight a role for ASC, upstream of the formation of the inflammasome, in regulating IRGM through its control on the Golgi. A similar mechanism occurs in response to Nigericin or infection with Zika virus (ZIKV). We propose a model for a newly ascribed function of the inflammasome components in Golgi structural remodeling.

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The inflammasome components NLRP3 and ASC act in concert with IRGM to rearrange the Golgi during HCV infection.

Journal of Virology ◽

10.1128/jvi.00826-20 ◽

2020 ◽

Author(s):

Coralie F. Daussy ◽

Sarah C. Monard ◽

Coralie Guy ◽

Sara Muñoz-González ◽

Maxime Chazal ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Hcv Infection ◽

Pyrin Domain ◽

Inflammasome Component ◽

Infected Cells ◽

Golgi Fragmentation ◽

Golgi Protein ◽

Golgi Structure

Hepatitis C virus (HCV) infection triggers Golgi fragmentation through the Golgi-resident protein immunity-related GTPase M (IRGM). Here, we report the role of NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) and ASC (Apoptosis-associated speck-like protein containing a CARD), two inflammasome components, in the initial events leading to this fragmentation. We show that ASC resides at the Golgi with IRGM at homeostasis. Upon infection, ASC dissociates from both IRGM and Golgi and associates with HCV-induced NLRP3. NLRP3 silencing inhibits Golgi fragmentation. ASC silencing disrupts the Golgi structure in both control and infected cells and reduces the localization of IRGM at the Golgi. IRGM-depletion in the ASC silenced cells cannot totally restore the Golgi structure. These data highlight a role for ASC, upstream of the formation of the inflammasome, in regulating IRGM through its control on the Golgi. A similar mechanism occurs in response to Nigericin treatment, but not in cells infected with another member of the Flaviviridae family, Zika virus (ZIKV). We propose a model for a newly ascribed function of the inflammasome components in Golgi structural remodeling during certain stimuli. IMPORTANCE Numerous pathogens can affect cellular homeostasis and organelle dynamics. Hepatitis C virus (HCV) triggers Golgi fragmentation through the immunity-related GTPase M (IRGM), a resident Golgi protein to enhance its lipid supply for replication. Here, we reveal the role of the inflammasome components NLRP3 and ASC in this process, thus uncovering a new interplay between effectors of inflammation and viral infection or stress. We show that the inflammasome component ASC resides at the Golgi under homeostasis and associates with IRGM. Upon HCV infection, ASC is recruited to NLRP3 and dissociates from IRGM causing Golgi fragmentation. Our results uncover that aside from their known function in the inflammation response, this host defense regulators also ensure the maintenance of intact intracellular structure in homeostasis status, while their activation relieves factors leading to Golgi remodeling.

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Hepatitis C Virus Infection of Human Thyrocytes: Metabolic, Hormonal, and Immunological Implications

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgz241 ◽

2019 ◽

Vol 105 (4) ◽

pp. 1157-1168

Author(s):

Sara Salehi Hammerstad ◽

Jason T Blackard ◽

Angela Lombardi ◽

Randall P Owen ◽

Erlinda Concepcion ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Cell Line ◽

Proinflammatory Cytokines ◽

Thyroid Dysfunction ◽

Hcv Infection ◽

Human Thyroid ◽

General Mechanism ◽

Thyroid Cells ◽

Infected Cells

Abstract Context Hepatitis C virus (HCV) infection is a prevalent disease worldwide. Thyroid dysfunction is one of the most common extrahepatic manifestations of HCV infection. We hypothesized that HCV can directly infect human thyrocytes thereby causing thyroid dysfunction. Setting Human thyrocytes in primary cell culture, ML-1 human thyroid cell line, and Huh7.5 human hepatocyte cell line were infected with HCV using the Huh7.5JFH1 cell line that releases infectious HCV virions. After infection, the release of new virions, production of proinflammatory cytokines, and expression of miR-122 were evaluated. Ribonucleic acid (RNA) extracted from HCV-infected cells and mock-infected cells was subjected to RNA sequencing and transcriptomic analysis. Ingenuity pathway analysis was used to detect up- and down-regulated pathways. Results Human thyrocytes express major HCV entry factors including CD81, occludin, claudin-1, and scavenger receptor class B1. Viral infection of thyroid cells was confirmed by detection of HCV core protein in supernatants and negative-sense HCV RNA in cell lysates. HCV infection of thyrocytes induced the production of the chemokine CXCL-8 and the proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and significantly increased the expression of miR-122. Moreover, HCV infection of thyrocytes decreased expression of the thyroid peroxidase and thyroglobulin genes and increased expression of the deiodinase 2 gene. The top upregulated pathways in HCV-infected thyrocytes were immune pathways and metabolic pathways, while infected hepatocytes upregulated lipid and glucose metabolism pathways as previously reported. Conclusions HCV infection may induce thyroid dysfunction by different mechanisms including direct infection of thyrocytes leading to activation of inflammatory pathways and upregulation of miR-122. These findings support a general mechanism for viral induction of autoimmunity through direct infection of target tissues.

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Hepatitis C virus enhances Rubicon expression, leading to autophagy inhibition and intracellular innate immune activation

Scientific Reports ◽

10.1038/s41598-020-72294-y ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Yuto Shiode ◽

Hayato Hikita ◽

Satoshi Tanaka ◽

Kumiko Shirai ◽

Akira Doi ◽

...

Keyword(s):

Immune Response ◽

Hepatitis C Virus ◽

Hepatitis C ◽

Late Stage ◽

Early Stage ◽

Hcv Infection ◽

Infected Cells ◽

The Impact ◽

Chronic Hepatitis C Patients

Abstract Autophagy, a degradation system, works to maintain cellular homeostasis. However, as the impact of Hepatitis C virus (HCV) infection on hepatocyte autophagy and its effect on HCV replication remain unclear, we examined them. HCV infection suppressed late-stage autophagy and increased Rubicon. siRNA-mediated knockdown of Rubicon promoted autophagy in HCV-infected cells. In Huh-7 cells harbouring the HCV replicon, Rubicon knockdown downregulated the expression of type 1 interferon (IFN)-related genes and upregulated HCV replication. Rubicon overexpression or administration of bafilomycin A1 or chloroquine, an inhibitor of late-stage autophagy, suppressed autophagy and activated the type 1 IFN pathway. On the other hand, Atg7 knockout suppressed early-stage autophagy and did not activate the type 1 IFN pathway. In livers of humanized liver chimeric mice, HCV infection increased Rubicon and enhanced type 1 IFN signalling. Elimination of HCV in the mice reduced the increase in Rubicon due to HCV infection. The expression levels of Rubicon and IFN-stimulated genes in chronic hepatitis C patients were higher than those in non-B, non-C hepatitis patients. HCV infection increased Rubicon and suppressed hepatocyte autophagy, leading to activation of the intracellular immune response. Rubicon induction is involved in HCV replication via activation of the intracellular immune response.

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Hepatitis C Virus Infection and B-Cell Non-Hodgkin’s Lymphoma.

Blood ◽

10.1182/blood.v106.11.4668.4668 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4668-4668

Author(s):

Janet G. Grudeva

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

B Cell ◽

Hcv Infection ◽

Control Group ◽

Cell Infection ◽

Serum Samples ◽

Pathogenetic Role ◽

Significant Difference

Backgroud: An increasing number of bacterial and viral infections have been linked with specific subtypes of lymphoma. Preliminary evidence suggests that hepatitis C virus (HCV) might play a pathogenetic role in autoimmune-related, non-malignant B-cell lymphoproliferation, as well as a subset of B-cell non-Hodgkin, s lymphomas (B-NHL), often with extranodal localization. Design and methods: The study was conducted in the Department of Hematology and consisted 149 (86 male, 63 female) untreated patients with a new diagnosis of B-NHL for 5-years period (2000–2004). HCV infection was investigated by testing for HCV antibodies in serum samples. The controls were 587 patients (without intravenous drug users) in other departments of the same hospital. Results: HCV infection was documented in 13 cases (8,4%) with NHL. The infected patients were not clinically relevant cryoglobulinemic activity, increased rate of autoimmune disorders and extranodal localizations prevalence. There was statistically significant difference between the NHL and control group (p<0,01) and no statistically significant difference between man/women carriers (p>0,05) into the NHL group. Overall, the clinical outcome of HCV-positive NHL does not seem to be different from that of NHL patients without HCV infection. However, the evidence of a significant liver injury may predict a worse prognosis in these cases. Conclusions: Our date suggest that HCV infection may be associated with B-NHL. With regard to the mechanism(s) by which HCV might favor B-cell expansion and malignant transformation, most date support an indirect pathogenetic role of the virus as an exogenous trigger. A direct oncogenetic role of HCV by direct cell infection and deregulation has only been hypothesized on the basis of the lymphotropism of the virus.

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Role of Anti-Hepatitis C Virus (HCV) Treatment in HCV-Related, Low-Grade, B-Cell, Non-Hodgkin's Lymphoma: A Multicenter Italian Experience

Journal of Clinical Oncology ◽

10.1200/jco.2005.06.008 ◽

2005 ◽

Vol 23 (3) ◽

pp. 468-473 ◽

Cited By ~ 174

Author(s):

Daniele Vallisa ◽

Patrizia Bernuzzi ◽

Luca Arcaini ◽

Stefano Sacchi ◽

Vittorio Callea ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

B Cell ◽

Antiviral Treatment ◽

Complete Response ◽

Hcv Infection ◽

Low Grade ◽

Hcv Treatment ◽

Hematologic Response

Purpose Hepatitis C virus (HCV) is endemic in some areas of Northwestern Europe and the United States. HCV has been shown to play a role in the development of both hepatocellular carcinoma and B-cell non-Hodgkin's lymphoma (B-NHL). The biologic mechanisms underlying the lymphomagenic activity of the virus so far are under investigation. In this study, the role of antiviral (anti-HCV) treatment in B-NHL associated with HCV infection is evaluated. Patients and Methods Thirteen patients with histologically proven low-grade B-NHL characterized by an indolent course (ie, doubling time no less than 1 year, no bulky disease) and carrying HCV infection were enrolled on the study. All patients underwent antiviral treatment alone with pegilated interferon and ribavirin. Response assessment took place at 6 and 12 months. Results Of the twelve assessable patients, seven (58%) achieved complete response and two (16%) partial hematologic response at 14.1 ± 9.7 months (range, 2 to 24 months, median follow-up, 14 months), while two had stable disease with only one patient experiencing progression of disease. Hematologic responses (complete and partial, 75%) were highly significantly associated to clearance or decrease in serum HCV viral load following treatment (P = .005). Virologic response was more likely to be seen in HCV genotype 2 (P = .035), while hematologic response did not correlate with the viral genotype. Treatment-related toxicity did not cause discontinuation of therapy in all but two patients, one of whom, however, achieved complete response. Conclusion This experience strongly provides a role for antiviral treatment in patients affected by HCV-related, low-grade, B-cell NHL.

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Elevated Levels of IL-33, IL-17 and IL-25 Indicate the Progression from Chronicity to Hepatocellular Carcinoma in Hepatitis C Virus Patients

Pathogens ◽

10.3390/pathogens11010057 ◽

2022 ◽

Vol 11 (1) ◽

pp. 57

Author(s):

Momen Askoura ◽

Hisham A. Abbas ◽

Hadeel AlSadoun ◽

Wesam H. Abdulaal ◽

Amr S. Abu Lila ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Hepatitis C Virus ◽

Viral Load ◽

Hepatitis C ◽

Liver Fibrosis ◽

Serum Level ◽

Viral Infections ◽

Serum Levels ◽

Chronic Patients

Hepatitis C virus (HCV) is one of the most epidemic viral infections in the world. Three-quarters of individuals infected with HCV become chronic. As a consequence of persistent inflammation, a considerable percentage of chronic patients progress to liver fibrosis, cirrhosis, and finally hepatocellular carcinoma. Cytokines, which are particularly produced from T-helper cells, play a crucial role in immune protection against HCV and the progression of the disease as well. In this study, the role of interleukins IL-33, IL-17, and IL-25 in HCV patients and progression of disease from chronicity to hepatocellular carcinoma will be characterized in order to use them as biomarkers of disease progression. The serum levels of the tested interleukins were measured in patients suffering from chronic hepatitis C (CHC), hepatocellular carcinoma (HCC), and healthy controls (C), and their levels were correlated to the degree of liver fibrosis, liver fibrosis markers and viral load. In contrast to the IL-25 serum level, which increased in patients suffering from HCC only, the serum levels of both IL-33 and IL-17 increased significantly in those patients suffering from CHC and HCC. In addition, IL-33 serum level was found to increase by liver fibrosis progression and viral load, in contrast to both IL-17 and IL-25. Current results indicate a significant role of IL-33 in liver inflammation and fibrosis progress in CHC, whereas IL-17 and IL-25 may be used as biomarkers for the development of hepatocellular carcinoma.

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The role of neutralizing antibodies in hepatitis C virus infection

Journal of General Virology ◽

10.1099/vir.0.035956-0 ◽

2012 ◽

Vol 93 (1) ◽

pp. 1-19 ◽

Cited By ~ 43

Author(s):

Victoria C. Edwards ◽

Alexander W. Tarr ◽

Richard A. Urbanowicz ◽

Jonathan K. Ball

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Neutralizing Antibodies ◽

Primary Liver Cancer ◽

Protective Role ◽

Hcv Infection ◽

Comprehensive Overview ◽

Therapeutic Benefits ◽

Natural Target

Hepatitis C virus (HCV) is a blood-borne virus estimated to infect around 170 million people worldwide and is, therefore, a major disease burden. In some individuals the virus is spontaneously cleared during the acute phase of infection, whilst in others a persistent infection ensues. Of those persistently infected, severe liver diseases such as cirrhosis and primary liver cancer may develop, although many individuals remain asymptomatic. A range of factors shape the course of HCV infection, not least host genetic polymorphisms and host immunity. A number of studies have shown that neutralizing antibodies (nAb) arise during HCV infection, but that these antibodies differ in their breadth and mechanism of neutralization. Recent studies, using both mAbs and polyclonal sera, have provided an insight into neutralizing determinants and the likely protective role of antibodies during infection. This understanding has helped to shape our knowledge of the overall structure of the HCV envelope glycoproteins – the natural target for nAb. Most nAb identified to date target receptor-binding sites within the envelope glycoprotein E2. However, there is some evidence that other viral epitopes may be targets for antibody neutralization, suggesting the need to broaden the search for neutralization epitopes beyond E2. This review provides a comprehensive overview of our current understanding of the role played by nAb in HCV infection and disease outcome and explores the limitations in the study systems currently used. In addition, we briefly discuss the potential therapeutic benefits of nAb and efforts to develop nAb-based therapies.

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N-Myc Downstream-Regulated Gene 1 Restricts Hepatitis C Virus Propagation by Regulating Lipid Droplet Biogenesis and Viral Assembly

Journal of Virology ◽

10.1128/jvi.01166-17 ◽

2017 ◽

Vol 92 (2) ◽

Cited By ~ 5

Author(s):

Cameron J. Schweitzer ◽

Fang Zhang ◽

Audrey Boyer ◽

Kristin Valdez ◽

Maggie Cam ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Liver Cancer ◽

Lipid Droplet ◽

Viral Infections ◽

Rna Virus ◽

Viral Assembly ◽

Hcv Infection ◽

Host Cells ◽

Virus Propagation

ABSTRACT Host cells harbor various intrinsic mechanisms to restrict viral infections as a first line of antiviral defense. Viruses have evolved various countermeasures against these antiviral mechanisms. Here we show that N-Myc downstream-regulated gene 1 (NDRG1) limits productive hepatitis C virus (HCV) infection by inhibiting viral assembly. Interestingly, HCV infection downregulates NDRG1 protein and mRNA expression. The loss of NDRG1 increases the size and number of lipid droplets, which are the sites of HCV assembly. HCV suppresses NDRG1 expression by upregulating MYC, which directly inhibits the transcription of NDRG1. The upregulation of MYC also leads to the reduced expression of the NDRG1-specific kinase serum/glucocorticoid-regulated kinase 1 (SGK1), resulting in a markedly diminished phosphorylation of NDRG1. The knockdown of MYC during HCV infection rescues NDRG1 expression and phosphorylation, suggesting that MYC regulates NDRG1 at both the transcriptional and posttranslational levels. Overall, our results suggest that NDRG1 restricts HCV assembly by limiting lipid droplet formation. HCV counteracts this intrinsic antiviral mechanism by downregulating NDRG1 via a MYC-dependent mechanism. IMPORTANCE Hepatitis C virus (HCV) is an enveloped single-stranded RNA virus that targets hepatocytes in the liver. HCV is a leading cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma, and estimates suggest a global prevalence of 2.35%. Up to 80% of acutely infected individuals will develop chronic infection, and as many as 5% eventually progress to liver cancer. An understanding of the mechanisms behind virus-host interactions and viral carcinogenesis is still lacking. The significance of our research is that it identifies a previously unknown relationship between HCV and a known tumor-associated gene. Furthermore, our data point to a new role for this gene in the liver and in lipid metabolism. Thus, HCV infection serves as a great biological model to advance our knowledge of liver functions and the development of liver cancer.

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Neglected but Important Role of Apolipoprotein E Exchange in Hepatitis C Virus Infection

Journal of Virology ◽

10.1128/jvi.01353-16 ◽

2016 ◽

Vol 90 (21) ◽

pp. 9632-9643 ◽

Cited By ~ 30

Author(s):

Zaili Yang ◽

Xiaoning Wang ◽

Xiumei Chi ◽

Fanfan Zhao ◽

Jinxu Guo ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Cell Surface ◽

Apolipoprotein E ◽

Virus Assembly ◽

Hcv Infection ◽

Apoe Level ◽

New Perspective ◽

Apoe Expression

ABSTRACT Hepatitis C virus (HCV) is a major cause of chronic liver disease, infecting approximately 170 million people worldwide. HCV assembly is tightly associated with the lipoprotein pathway. Exchangeable apolipoprotein E (apoE) is incorporated on infectious HCV virions and is important for infectious HCV virion morphogenesis and entry. Moreover, the virion apoE level is positively correlated with its ability to escape E2 antibody neutralization. However, the role of apoE exchange in the HCV life cycle is unclear. In this study, the relationship between apoE expression and cell permissiveness to HCV infection was assessed by infecting apoE knockdown and derived apoE rescue cell lines with HCV. Exchange of apoE between lipoproteins and HCV lipoviral particles (LVPs) was evaluated by immunoprecipitation, infectivity testing, and viral genome quantification. Cell and heparin column binding assays were applied to determine the attachment efficiency of LVPs with different levels of incorporated apoE. The results showed that cell permissiveness for HCV infection was determined by exogenous apoE-associated lipoproteins. Furthermore, apoE exchange did occur between HCV LVPs and lipoproteins, which was important to maintain a high apoE level on LVPs. Lipid-free apoE was capable of enhancing HCV infectivity for apoE knockdown cells but not apoE rescue cells. A higher apoE level on LVPs conferred more efficient LVP attachment to both the cell surface and heparin beads. This study revealed that exogenous apoE-incorporating lipoproteins from uninfected hepatocytes safeguarded the apoE level of LVPs for more efficient attachment during HCV infection. IMPORTANCE In this study, a neglected but important role of apoE exchange in HCV LVP infectivity after virus assembly and release was identified. The data indicated that apoE expression level in uninfected cells is important for high permissiveness to HCV infection. Secreted apoE-associated lipoprotein specifically enhances infection of HCV LVPs. apoE exchange between HCV LVP and lipoproteins is important to maintain an adequate apoE level on LVPs for their efficient attachment to cell surface. These data defined for the first time an extracellular role of exchangeable apoE in HCV infection and suggested that exchangeable apolipoproteins reach a natural equilibrium between HCV LVPs and lipoprotein particles, which provides a new perspective to the understanding of the heterogeneity of HCV LVPs in composition.

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