scholarly journals Hepatitis C Virus Strain-Dependent Usage of Apolipoprotein E Modulates Assembly Efficiency and Specific Infectivity of Secreted Virions

2017 ◽  
Vol 91 (18) ◽  
Author(s):  
Romy Weller ◽  
Kathrin Hueging ◽  
Richard J. P. Brown ◽  
Daniel Todt ◽  
Sebastian Joecks ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Apolipoprotein E ◽  
Virus Production ◽  
Host Factor ◽  
Cell Entry ◽  
Cell Type ◽  
Virus Particles ◽  
Strain Dependent ◽  
Apoe Expression

ABSTRACT Hepatitis C virus (HCV) is extraordinarily diverse and uses entry factors in a strain-specific manner. Virus particles associate with lipoproteins, and apolipoprotein E (ApoE) is critical for HCV assembly and infectivity. However, whether ApoE dependency is common to all HCV genotypes remains unknown. Therefore, we compared the roles of ApoE utilizing 10 virus strains from genotypes 1 through 7. ApoA and ApoC also support HCV assembly, so they may contribute to virus production in a strain-dependent fashion. Transcriptome sequencing (RNA-seq) revealed abundant coexpression of ApoE, ApoB, ApoA1, ApoA2, ApoC1, ApoC2, and ApoC3 in primary hepatocytes and in Huh-7.5 cells. Virus production was examined in Huh-7.5 cells with and without ApoE expression and in 293T cells where individual apolipoproteins (ApoE1, -E2, -E3, -A1, -A2, -C1, and -C3) were provided in trans. All strains were strictly ApoE dependent. However, ApoE involvement in virus production was strain and cell type specific, because some HCV strains poorly produced infectious virus in ApoE-expressing 293T cells and because ApoE knockout differentially affected virus production of HCV strains in Huh-7.5 cells. ApoE allelic isoforms (ApoE2, -E3, and -E4) complemented virus production of HCV strains to comparable degrees. All tested strains assembled infectious progeny with ApoE in preference to other exchangeable apolipoproteins (ApoA1, -A2, -C1, and -C3). The specific infectivity of HCV particles was similar for 293T- and Huh-7.5-derived particles for most strains; however, it differed by more than 100-fold in some viruses. Collectively, this study reveals strain-dependent and host cell-dependent use of ApoE during HCV assembly. These differences relate to the efficacy of virus production and also to the properties of released virus particles and therefore govern viral fitness at the level of assembly and cell entry. IMPORTANCE Chronic HCV infections are a major cause of liver disease. HCV is highly variable, and strain-specific determinants modulate the response to antiviral therapy, the natural course of infection, and cell entry factor usage. Here we explored whether host factor dependency of HCV in particle assembly is modulated by strain-dependent viral properties. We showed that all examined HCV strains, which represent all seven known genotypes, rely on ApoE expression for assembly of infectious progeny. However, the degree of ApoE dependence is modulated in a strain-specific and cell type-dependent manner. This indicates that HCV strains differ in their assembly properties and host factor usage during assembly of infectious progeny. Importantly, these differences relate not only to the efficiency of virus production and release but also to the infectiousness of virus particles. Thus, strain-dependent features of HCV modulate ApoE usage, with implications for virus fitness at the level of assembly and cell entry.

scholarly journals Infectivity of Hepatitis C Virus Is Influenced by Association with Apolipoprotein E Isoforms

2010 ◽  
Vol 84 (22) ◽  
pp. 12048-12057 ◽  
Author(s):  
Takayuki Hishiki ◽  
Yuko Shimizu ◽  
Reiri Tobita ◽  
Kazuo Sugiyama ◽  
Kazuya Ogawa ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Apolipoprotein E ◽  
Culture Medium ◽  
Low Density Lipoprotein ◽  
Ectopic Expression ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Virus Production ◽  
Low Density

ABSTRACT Hepatitis C virus (HCV) is a causative agent of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV in circulating blood associates with lipoproteins such as very low density lipoprotein (VLDL) and low-density lipoprotein (LDL). Although these associations suggest that lipoproteins are important for HCV infectivity, the roles of lipoproteins in HCV production and infectivity are not fully understood. To clarify the roles of lipoprotein in the HCV life cycle, we analyzed the effect of apolipoprotein E (ApoE), a component of lipoprotein, on virus production and infectivity. The production of infectious HCV was significantly reduced by the knockdown of ApoE. When an ApoE mutant that fails to be secreted into the culture medium was used, the amount of infectious HCV in the culture medium was dramatically reduced; the infectious HCV accumulated inside these cells, suggesting that infectious HCV must associate with ApoE prior to virus release. We performed rescue experiments in which ApoE isoforms were ectopically expressed in cells depleted of endogenous ApoE. The ectopic expression of the ApoE2 isoform, which has low affinity for the LDL receptor (LDLR), resulted in poor recovery of infectious HCV, whereas the expression of other isoforms, ApoE3 and ApoE4, rescued the production of infectious virus, raising it to an almost normal level. Furthermore, we found that the infectivity of HCV required both the LDLR and scavenger receptor class B, member I (SR-BI), ligands for ApoE. These findings indicate that ApoE is an essential apolipoprotein for HCV infectivity.

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

2016 ◽  
Vol 90 (21) ◽  
pp. 9632-9643 ◽  
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.

Triglyceride synthesis and hepatitis C virus production: Identification of a novel host factor as antiviral target

Hepatology ◽  
2011 ◽  
Vol 53 (3) ◽  
pp. 1046-1048 ◽  
Author(s):  
Catherine Schuster ◽  
Mathieu Lefèvre ◽  
Thomas F. Baumert
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Production ◽  
Host Factor ◽  
Triglyceride Synthesis ◽  
Novel Host

Influence of adipokines on cell entry, replication and virus production of Hepatitis C Virus

2013 ◽  
Vol 51 (01) ◽  
Author(s):  
P Behrendt ◽  
J Dörrbecker ◽  
K Huegging ◽  
H Wedemeyer ◽  
MP Manns ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Production ◽  
Cell Entry

scholarly journals Apolipoprotein E but Not B Is Required for the Formation of Infectious Hepatitis C Virus Particles

2009 ◽  
Vol 83 (24) ◽  
pp. 12680-12691 ◽  
Author(s):  
Jieyun Jiang ◽  
Guangxiang Luo
Keyword(s):  
Life Cycle ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Apolipoprotein E ◽  
Specific Interaction ◽  
Infectious Hepatitis ◽  
Production Studies ◽  
Growth Assay ◽  
Interfering Rna ◽  
Apoe Expression

ABSTRACT Our previous studies have found that hepatitis C virus (HCV) particles are enriched in apolipoprotein E (apoE) and that apoE is required for HCV infectivity and production. Studies by others, however, suggested that both microsomal transfer protein (MTP) and apoB are important for HCV production. To define the roles of apoB and apoE in the HCV life cycle, we developed a single-cycle HCV growth assay to determine the correlation of HCV assembly with apoB and apoE expression, as well as the influence of MTP inhibitors on the formation of HCV particles. The small interfering RNA (siRNA)-mediated knockdown of apoE expression remarkably suppressed the formation of HCV particles. However, apoE expressed ectopically could restore the defect of HCV production posed by the siRNA-mediated knockdown of endogenous apoE expression. In contrast, apoB-specific antibodies and siRNAs had no significant effect on HCV infectivity and production, respectively, suggesting that apoB does not play a significant role in the HCV life cycle. Additionally, two MTP inhibitors, CP-346086 and BMS-2101038, efficiently blocked secretion of apoB-containing lipoproteins but did not affect HCV production unless apoE expression and secretion were inhibited. At higher concentrations, however, MTP inhibitors blocked apoE expression and secretion and consequently suppressed the formation of HCV particles. Furthermore, apoE was found to be sensitive to trypsin digestion and to interact with NS5A in purified HCV particles and HCV-infected cells, as demonstrated by coimmunoprecipitation. Collectively, these findings demonstrate that apoE but not apoB is required for HCV assembly, probably via a specific interaction with NS5A.

Differentiated cells in prolonged hypoxia produce highly infectious native‐like hepatitis C virus particles

Hepatology ◽  
2021 ◽  
Author(s):  
Jade Cochard ◽  
Anne Bull‐Maurer ◽  
Clovis Tauber ◽  
Julien Burlaud‐Gaillard ◽  
Frédéric Mazurier ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Particles ◽  
Differentiated Cells

scholarly journals Identification of Keratin 23 as a Hepatitis C Virus-Induced Host Factor in the Human Liver

Cells ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 610 ◽  
Author(s):  
Volker Kinast ◽  
Stefan L. Leber ◽  
Richard J. P. Brown ◽  
Gabrielle Vieyres ◽  
Patrick Behrendt ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Liver Disease ◽  
Hepatitis C ◽  
Ectopic Expression ◽  
Host Factor ◽  
Hcv Infection ◽  
Mrna Levels ◽  
Structural Support ◽  
Protein Levels ◽  
Inducible Protein

Keratin proteins form intermediate filaments, which provide structural support for many tissues. Multiple keratin family members are reported to be associated with the progression of liver disease of multiple etiologies. For example, keratin 23 (KRT23) was reported as a stress-inducible protein, whose expression levels correlate with the severity of liver disease. Hepatitis C virus (HCV) is a human pathogen that causes chronic liver diseases including fibrosis, cirrhosis, and hepatocellular carcinoma. However, a link between KRT23 and hepatitis C virus (HCV) infection has not been reported previously. In this study, we investigated KRT23 mRNA levels in datasets from liver biopsies of chronic hepatitis C (CHC) patients and in primary human hepatocytes experimentally infected with HCV, in addition to hepatoma cells. Interestingly, in each of these specimens, we observed an HCV-dependent increase of mRNA levels. Importantly, the KRT23 protein levels in patient plasma decreased upon viral clearance. Ectopic expression of KRT23 enhanced HCV infection; however, CRIPSPR/Cas9-mediated knockout did not show altered replication efficiency. Taken together, our study identifies KRT23 as a novel, virus-induced host-factor for hepatitis C virus.

P0683 : Hepatitis C virus NS3-4A protease targets the host factor BNIP1 at a non-canonical cleavage site

2015 ◽  
Vol 62 ◽  
pp. S578
Author(s):  
H. Thi Lan Tran ◽  
K. Morikawa ◽  
F. Penin ◽  
M. Quadroni ◽  
J. Gouttenoire ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Cleavage Site ◽  
Host Factor
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