scholarly journals Modeling hepatitis C virus kinetics during liver transplantation reveals the role of the liver in virus clearance

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Louis Shekhtman ◽  
Miquel Navasa ◽  
Natasha Sansone ◽  
Gonzalo Crespo ◽  
Gitanjali Subramanya ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Kinetic Data ◽  
Culture Medium ◽  
Rapid Decline ◽  
Transplant Patients ◽  
Virus Clearance ◽  
Anhepatic Phase ◽  
Infected Cells

While the liver, specifically hepatocytes, are widely accepted as the main source of hepatitis C virus (HCV) production, the role of the liver/hepatocytes in clearance of circulating HCV remains unknown. Frequent HCV kinetic data were recorded and mathematically modeled from 5 liver-transplant patients throughout the anhepatic (absence of liver) phase and for 4 hours post-reperfusion. During the anhepatic phase, HCV remained at pre-anhepatic levels (n=3) or declined (n=2) with t1/2~1h. Immediately post-reperfusion, virus declined in a biphasic manner in 4 patients consisting of a rapid decline (t1/2=5min) followed by a slower decline (t1/2=67min). Consistent with the majority of patients in the anhepatic phase, when we monitored HCV clearance at 37°C from culture medium in the absence/presence of chronically infected hepatoma cells that were inhibited from secreting HCV, the HCV t1/2 in cell culture was longer in the absence of chronically HCV-infected cells. The results suggest that the liver plays a major role in the clearance of circulating HCV and that hepatocytes may be involved.

Role of Interleukin 28B Polymorphisms in Response to Interferon Based Therapy for Hepatitis C Virus Clearance

2018 ◽  
Vol 19 (3) ◽  
pp. 215-223 ◽  
Author(s):  
Manu Asthana ◽  
Sushil Kumar Sahu ◽  
Amit Kumar ◽  
Suchitra Mohanty ◽  
Sudipta Chakrabarti ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Interleukin 28B ◽  
Virus Clearance

scholarly journals Modeling hepatitis C virus kinetics during liver transplantation highlights the role of the liver in virus clearance

2020 ◽  
Author(s):  
Louis Shekhtman ◽  
Miquel Navasa ◽  
Natasha Sansone ◽  
Gonzalo Crespo ◽  
Gitanjali Subramanya ◽  
...  
Keyword(s):  
Cell Culture ◽  
Liver Transplantation ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Clearance Rate ◽  
Culture Medium ◽  
Viral Clearance ◽  
Huh7 Cells

AbstractWhile the liver, specifically hepatocytes, are widely accepted as the main source for hepatitis C virus (HCV) production, the role of the liver/hepatocytes in the clearance of circulating HCV remains largely unknown. Here we evaluated the function of the liver/hepatocytes in clearing virus from the circulation by investigating viral clearance during liver transplantation and from culture medium in vitro. Frequent HCV kinetic data during liver transplantation were recorded from 5 individuals throughout the anhepatic (AH) phase and for 4 hours after reperfusion (RP), along with recordings of fluid balances. Using mathematical modeling, the serum viral clearance rate, c, was estimated. Analogously, we monitored the clearance rate of HCV at 37°C from culture medium in vitro in the absence and presence of chronically infected Huh7 human hepatoma cells. During the AH phase, in 3 transplant cases viral levels remained at pre-AH levels, while in the other 2 cases HCV declined (half-life, t1/2~1h). Immediately post-RP, virus declined in a biphasic manner in Cases 1-4 consisting of an extremely rapid (median t1/2=5min) decline followed by a slower decline (HCV t1/2=67min). In Case 5, HCV remained at the same level post-RP as at the end of AH. Declines in virus level were not explained by adjusting for dilution from IV fluid and blood products. Consistent with what was observed in the majority of patients in the anhepatic phase, the t1/2 of HCV in cell culture was much longer in the absence of chronically HCV-infected Huh7 cells. Therefore, kinetic and modeling results from both in vivo liver transplantation cases and in vitro cell culture studies suggest that the liver plays a major role in clearing HCV from the circulation.

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

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.

scholarly journals Osteopontin Regulates Hepatitis C Virus (HCV) Replication and Assembly by Interacting with HCV Proteins and Lipid Droplets and by Binding to Receptors αVβ3 and CD44

2018 ◽  
Vol 92 (13) ◽  
pp. e02116-17 ◽  
Author(s):  
Jawed Iqbal ◽  
Mehuli Sarkar-Dutta ◽  
Steven McRae ◽  
Akshaya Ramachandran ◽  
Binod Kumar ◽  
...  
Keyword(s):  
Life Cycle ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Lipid Droplets ◽  
Critical Role ◽  
Migration And Invasion ◽  
Core Proteins ◽  
Important Relationship ◽  
Infected Cells

ABSTRACT Hepatitis C virus (HCV) replication and assembly occur at the specialized site of endoplasmic reticulum (ER) membranes and lipid droplets (LDs), respectively. Recently, several host proteins have been shown to be involved in HCV replication and assembly. In the present study, we demonstrated the important relationship among osteopontin (OPN), the ER, and LDs. OPN is a secreted phosphoprotein, and overexpression of OPN in hepatocellular carcinoma (HCC) tissue can lead to invasion and metastasis. OPN expression is also enhanced in HCV-associated HCC. Our recent studies have demonstrated the induction, proteolytic cleavage, and secretion of OPN in response to HCV infection. We also defined the critical role of secreted OPN in human hepatoma cell migration and invasion through binding to receptors integrin αVβ3 and CD44. However, the role of HCV-induced OPN in the HCV life cycle has not been elucidated. In this study, we showed a significant reduction in HCV replication, assembly, and infectivity in HCV-infected cells transfected with small interfering RNA (siRNA) against OPN, αVβ3, and CD44. We also observed the association of endogenous OPN with HCV proteins (NS3, NS5A, NS4A/B, NS5B, and core). Confocal microscopy revealed the colocalization of OPN with HCV NS5A and core in the ER and LDs, indicating a possible role for OPN in HCV replication and assembly. Interestingly, the secreted OPN activated HCV replication, infectivity, and assembly through binding to αVβ3 and CD44. Collectively, these observations provide evidence that HCV-induced OPN is critical for HCV replication and assembly. IMPORTANCE Recently, our studies uncovered the critical role of HCV-induced endogenous and secreted OPN in migration and invasion of hepatocytes. However, the role of OPN in the HCV life cycle has not been elucidated. In this study, we investigated the importance of OPN in HCV replication and assembly. We demonstrated that endogenous OPN associates with HCV NS3, NS5A, NS5B, and core proteins, which are in close proximity to the ER and LDs. Moreover, we showed that the interactions of secreted OPN with cell surface receptors αVβ3 and CD44 are critical for HCV replication and assembly. These observations provide evidence that HCV-induced endogenous and secreted OPN play pivotal roles in HCV replication and assembly in HCV-infected cells. Taken together, our findings clearly demonstrate that targeting OPN may provide opportunities for therapeutic intervention of HCV pathogenesis.

scholarly journals Regulation of Apolipoprotein E Trafficking by Hepatitis C Virus-Induced Autophagy

2018 ◽  
Vol 92 (14) ◽  
Author(s):  
Ja Yeon Kim ◽  
Jing-hsiung James Ou
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Apolipoprotein E ◽  
Protein Degradation ◽  
Envelope Protein ◽  
Subgenomic Rna ◽  
Viral Particles ◽  
Infected Cells ◽  
Rna Replicon

ABSTRACTApolipoprotein E (ApoE) plays an important role in the maturation and infectivity of hepatitis C virus (HCV). By analyzing the subcellular localization of ApoE in Huh7 hepatoma cells that harbored an HCV subgenomic RNA replicon, we found that ApoE colocalized with autophagosomes. This colocalization was marginally detected in HCV-infected cells, apparently due to the depletion of ApoE by HCV, as treatment with bafilomycin A1 (BafA1), a vacuolar ATPase inhibitor that inhibits autophagic protein degradation, partially restored the ApoE level and enhanced its colocalization with autophagosomes in HCV-infected cells. The role of HCV-induced autophagy in the degradation of ApoE was further supported by the observations that nutrient starvation, which induces autophagic protein degradation, led to the loss of ApoE in HCV subgenomic RNA replicon cells and that the knockdown of ATG7, a protein essential for the formation of autophagic vacuoles, increased the ApoE level in cells with productive HCV replication. Interestingly, the inhibition of autophagy by ATG7 knockdown reduced the colocalization of ApoE with the HCV E2 envelope protein and the HCV titers released from cells. In contrast, the treatment of cells with BafA1 enhanced the colocalization of ApoE and HCV E2 and increased both intracellular and extracellular HCV titers. These results indicated that autophagy played an important role in the trafficking of ApoE in HCV-infected cells. While it led to autophagic degradation of ApoE, it also promoted the interaction between ApoE and HCV E2 to enhance the production of infectious progeny viral particles.IMPORTANCEHepatitis C virus (HCV) is one of the most important human pathogens. Its virion is associated with apolipoprotein E (ApoE), which enhances its infectivity. HCV induces autophagy to enhance its replication. In this report, we demonstrate that autophagy plays an important role in the trafficking of ApoE in HCV-infected cells. This leads to the degradation of ApoE by autophagy. However, if the autophagic protein degradation is inhibited, ApoE is stabilized and colocalized with autophagosomes. This leads to its enhanced colocalization with the HCV E2 envelope protein and increased production of infectious progeny viral particles. If autophagy is inhibited by suppressing the expression of ATG7, a gene essential for the formation of autophagosomes, the colocalization of ApoE with E2 is reduced, resulting in the reduction of progeny viral titers. These results indicate an important role of autophagy in the transport of ApoE to promote the production of infectious HCV particles.

scholarly journals Peptide inhibitors of hepatitis C virus core oligomerization and virus production

2009 ◽  
Vol 90 (6) ◽  
pp. 1319-1328 ◽  
Author(s):  
S. Kota ◽  
C. Coito ◽  
G. Mousseau ◽  
J.-P. Lavergne ◽  
A. D. Strosberg
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Virus Production ◽  
Peptide Inhibitors ◽  
Rt Pcr ◽  
Protein Protein Interaction ◽  
Virus Core ◽  
Infected Cells

Hepatitis C virus (HCV) nucleocapsid assembly requires dimerization of the core protein, an essential step in the formation of the virus particle. We developed a novel quantitative assay for monitoring this protein–protein interaction, with the goal of identifying inhibitors of core dimerization that might block HCV production in infected Huh-7.5 hepatoma cells. Two core-derived, 18-residue peptides were found that inhibited the dimerization of a fragment of core comprising residues 1–106 (core106) by 68 and 63 %, respectively. A third, related 15-residue peptide displayed 50 % inhibition, with an IC50 of 21.9 μM. This peptide was shown, by fluorescence polarization, to bind directly to core106 with a K d of 1.9 μM and was displaced by the unlabelled peptide with an IC50 of 18.7 μM. When measured by surface plasmon resonance, the same peptide bound core169 with a K d of 7.2 μM. When added to HCV-infected cells, each of the three peptides blocked release, but not replication, of infectious virus. When measured by real-time RT-PCR, the RNA levels were reduced by 7-fold. The 15-residue peptide had no effect on HIV propagation. Such inhibitors may constitute useful tools to investigate the role of core dimerization in the virus cycle.

scholarly journals Longitudinal variation in hepatitis C virus (HCV) viraemia and early course of HCV infection after liver transplantation for HCV cirrhosis: the role of different immunosuppressive regimens

Gut ◽  
1999 ◽  
Vol 45 (3) ◽  
pp. 427-434 ◽  
Author(s):  
G V Papatheodoridis ◽  
S G R G Barton ◽  
D Andrew ◽  
G Clewley ◽  
S Davies ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Acute Hepatitis ◽  
Hcv Infection ◽  
Hcv Rna ◽  
Post Transplant ◽  
Early Course ◽  
Transplant Patients ◽  
Rna Levels

BACKGROUNDThe role of the type of immunosuppression in the natural history of post-transplant hepatitis C virus (HCV) infection is unclear.AIMSTo evaluate the fluctuation of HCV viraemia and the early course of infection, and their relation to the type of immunosuppression in HCV transplant patients.METHODSIn 47 HCV transplant patients, serum HCV RNA levels were determined pretransplant and at one and two weeks, and three and 12 months after transplant. Initial immunosuppression was triple (cyclosporin, azathioprine, prednisolone) in 31, double (cyclosporin, prednisolone) in five, and single (cyclosporin or tacrolimus) in 11 patients. Prednisolone was withdrawn at a median of six months.RESULTSAt three months, HCV RNA levels were higher in patients with single than with triple or double initial therapy. At 12 months, HCV RNA levels correlated only with duration of prednisolone treatment and were relatively higher in patients with triple compared with single initial immunosuppression. A higher necroinflammatory activity at 12 months post-transplant was found in patients with post-transplant acute hepatitis compared with those without. Extent of fibrosis at 12 months was associated with the 12 month HCV RNA level and occurrence of post-transplant acute hepatitis.CONCLUSIONSHCV RNA levels at three months after transplant are higher in patients treated with single initial immunosuppressive therapy, but at 12 months are higher in patients with longer duration of steroid treatment. HCV viraemia at 12 months seems to be particularly important, as its levels are strongly correlated with the severity of fibrosis.

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

2020 ◽  
Author(s):  
Coralie F. Daussy ◽  
Sarah C. Monard ◽  
Coralie Guy ◽  
Sara Muñoz-González ◽  
Maxime Chazal ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Zika Virus ◽  
Viral Infections ◽  
Hcv Infection ◽  
Structural Remodeling ◽  
Infected Cells ◽  
Golgi Fragmentation ◽  
Golgi Structure

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.

Role of autophagy in hepatitis C virus replication

2019 ◽  
Author(s):  
WI Twu ◽  
K Tabata ◽  
D Paul ◽  
R Bartenschlager
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Replication
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