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Dao Thi VL, Granier C, Zeisel MB, Guérin M, Mancip J, Granio O, Penin F, Lavillette D, Bartenschlager R, Baumert TF, Cosset FL, Dreux M. Characterization of hepatitis C virus particle subpopulations reveals multiple usage of the scavenger receptor BI for entry steps. J Biol Chem 2012; 287:31242-57. [PMID: 22767607 PMCID: PMC3438956 DOI: 10.1074/jbc.m112.365924] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 06/29/2012] [Indexed: 12/21/2022] Open
Abstract
Hepatitis C virus (HCV) particles assemble along the very low density lipoprotein pathway and are released from hepatocytes as entities varying in their degree of lipid and apolipoprotein (apo) association as well as buoyant densities. Little is known about the cell entry pathway of these different HCV particle subpopulations, which likely occurs by regulated spatiotemporal processes involving several cell surface molecules. One of these molecules is the scavenger receptor BI (SR-BI), a receptor for high density lipoprotein that can bind to the HCV glycoprotein E2. By studying the entry properties of infectious virus subpopulations differing in their buoyant densities, we show that these HCV particles utilize SR-BI in a manifold manner. First, SR-BI mediates primary attachment of HCV particles of intermediate density to cells. These initial interactions involve apolipoproteins, such as apolipoprotein E, present on the surface of HCV particles, but not the E2 glycoprotein, suggesting that lipoprotein components in the virion act as host-derived ligands for important entry factors such as SR-BI. Second, we found that in contrast to this initial attachment, SR-BI mediates entry of HCV particles independent of their buoyant density. This function of SR-BI does not depend on E2/SR-BI interaction but relies on the lipid transfer activity of SR-BI, probably by facilitating entry steps along with other HCV entry co-factors. Finally, our results underscore a third function of SR-BI governed by specific residues in hypervariable region 1 of E2 leading to enhanced cell entry and depending on SR-BI ability to bind to E2.
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Affiliation(s)
- Viet Loan Dao Thi
- From the INSERM, U758, Human Virology Laboratory, EVIR team, Lyon, F-69007, France
- Ecole Normale Supérieure de Lyon, Lyon, F-69007, France
- Université de Lyon, UCB-Lyon1, Lyon, F-69007, France
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
| | - Christelle Granier
- From the INSERM, U758, Human Virology Laboratory, EVIR team, Lyon, F-69007, France
- Ecole Normale Supérieure de Lyon, Lyon, F-69007, France
- Université de Lyon, UCB-Lyon1, Lyon, F-69007, France
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
| | - Mirjam B. Zeisel
- INSERM, U748, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
| | | | - Jimmy Mancip
- From the INSERM, U758, Human Virology Laboratory, EVIR team, Lyon, F-69007, France
- Ecole Normale Supérieure de Lyon, Lyon, F-69007, France
- Université de Lyon, UCB-Lyon1, Lyon, F-69007, France
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
| | - Ophélia Granio
- From the INSERM, U758, Human Virology Laboratory, EVIR team, Lyon, F-69007, France
- Ecole Normale Supérieure de Lyon, Lyon, F-69007, France
- Université de Lyon, UCB-Lyon1, Lyon, F-69007, France
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
| | - François Penin
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
- Institut de Biologie et Chimie des Protéines, UMR 5086 CNRS, Université de Lyon, Lyon, F-69367, France
| | - Dimitri Lavillette
- From the INSERM, U758, Human Virology Laboratory, EVIR team, Lyon, F-69007, France
- Ecole Normale Supérieure de Lyon, Lyon, F-69007, France
- Université de Lyon, UCB-Lyon1, Lyon, F-69007, France
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
| | - Ralf Bartenschlager
- the Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany, and
| | - Thomas F. Baumert
- INSERM, U748, 67000, Strasbourg, France
- Université de Strasbourg, 67000, Strasbourg, France
- Pôle Hepato-digestif, Hôpitaux Universitaires de Strasbourg, 67000, Strasbourg, France
| | - François-Loïc Cosset
- From the INSERM, U758, Human Virology Laboratory, EVIR team, Lyon, F-69007, France
- Ecole Normale Supérieure de Lyon, Lyon, F-69007, France
- Université de Lyon, UCB-Lyon1, Lyon, F-69007, France
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
| | - Marlène Dreux
- From the INSERM, U758, Human Virology Laboratory, EVIR team, Lyon, F-69007, France
- Ecole Normale Supérieure de Lyon, Lyon, F-69007, France
- Université de Lyon, UCB-Lyon1, Lyon, F-69007, France
- LabEx Ecofect, Université de Lyon, Lyon, F-69007, France
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Sheridan DA, Bridge SH, Felmlee DJ, Crossey MME, Thomas HC, Taylor-Robinson SD, Toms GL, Neely RDG, Bassendine MF. Apolipoprotein-E and hepatitis C lipoviral particles in genotype 1 infection: evidence for an association with interferon sensitivity. J Hepatol 2012; 57:32-8. [PMID: 22414761 DOI: 10.1016/j.jhep.2012.02.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 01/04/2012] [Accepted: 02/01/2012] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Hepatitis C virus (HCV) interacts with apolipoproteins B (apoB) and E (apoE) to form infectious lipoviral particles (LVP). Response to peginterferon is influenced by interferon-stimulated genes (ISGs) and IL28B genotype. LDL cholesterol (LDL-C) also predicts interferon response, therefore we hypothesised that LVP may also be associated with interferon sensitivity. METHODS LVP (HCV RNA density ≤1.07 g/ml) and 'non-LVP' (d >1.07 g/ml) were measured in 72 fasted HCV-G1 patients by iodixanol density gradient ultracentrifugation and the LVP ratio (LVP/LVP+non-LVP) was calculated. Fasting lipid profiles and apolipoproteins B and E were measured. Interferon-gamma-inducible protein 10 kDa (IP10), a marker of ISGs, was measured by ELISA. RESULTS Complete early virological response (EVR) was associated with lower apoE (23.9±7.7 vs. 36.1±15.3 mg/L, p=0.013), higher LDL-C (p=0.039) and lower LVP ratios (p=0.022) compared to null responders. In multivariate linear regression analysis, apoE was independently associated with LVP (R(2) 19.5%, p=0.003) and LVP ratio (p=0.042), and negatively with LDL-C (p<0.001). IP10 was significantly associated with ApoB (p=0.001) and liver stiffness (p=0.032). IL28B rs12979860 CC was associated with complete EVR (p=0.044), low apoE (CC 28±11 vs. CT/TT 35±13 mg/L, p=0.048) and higher non-LVP (p=0.008). Logistic regression analysis indicated that patients with high LVP ratios were less likely to have EVR (odds ratio 0.01, p=0.018). CONCLUSIONS In HCV-G1, interferon sensitivity is characterised by low LVP ratios and low apoE levels in addition to higher LDL-C and IL28B rs12979860 CC. Null-response is associated with increased LVP ratio. The association of apoE and LVP with peginterferon treatment response suggests that lipid modulation is a potential target to modify interferon sensitivity.
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Affiliation(s)
- David A Sheridan
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom.
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56
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Lipoprotein lipase inhibits hepatitis C virus (HCV) infection by blocking virus cell entry. PLoS One 2011; 6:e26637. [PMID: 22039521 PMCID: PMC3198807 DOI: 10.1371/journal.pone.0026637] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 09/29/2011] [Indexed: 12/12/2022] Open
Abstract
A distinctive feature of HCV is that its life cycle depends on lipoprotein metabolism. Viral morphogenesis and secretion follow the very low-density lipoprotein (VLDL) biogenesis pathway and, consequently, infectious HCV in the serum is associated with triglyceride-rich lipoproteins (TRL). Lipoprotein lipase (LPL) hydrolyzes TRL within chylomicrons and VLDL but, independently of its catalytic activity, it has a bridging activity, mediating the hepatic uptake of chylomicrons and VLDL remnants. We previously showed that exogenously added LPL increases HCV binding to hepatoma cells by acting as a bridge between virus-associated lipoproteins and cell surface heparan sulfate, while simultaneously decreasing infection levels. We show here that LPL efficiently inhibits cell infection with two HCV strains produced in hepatoma cells or in primary human hepatocytes transplanted into uPA-SCID mice with fully functional human ApoB-lipoprotein profiles. Viruses produced in vitro or in vivo were separated on iodixanol gradients into low and higher density populations, and the infection of Huh 7.5 cells by both virus populations was inhibited by LPL. The effect of LPL depended on its enzymatic activity. However, the lipase inhibitor tetrahydrolipstatin restored only a minor part of HCV infectivity, suggesting an important role of the LPL bridging function in the inhibition of infection. We followed HCV cell entry by immunoelectron microscopy with anti-envelope and anti-core antibodies. These analyses demonstrated the internalization of virus particles into hepatoma cells and their presence in intracellular vesicles and associated with lipid droplets. In the presence of LPL, HCV was retained at the cell surface. We conclude that LPL efficiently inhibits HCV infection by acting on TRL associated with HCV particles through mechanisms involving its lipolytic function, but mostly its bridging function. These mechanisms lead to immobilization of the virus at the cell surface. HCV-associated lipoproteins may therefore be a promising target for the development of new therapeutic approaches.
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57
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Thomson EC, Smith JA, Klenerman P. The natural history of early hepatitis C virus evolution; lessons from a global outbreak in human immunodeficiency virus-1-infected individuals. J Gen Virol 2011; 92:2227-2236. [PMID: 21775583 PMCID: PMC3347798 DOI: 10.1099/vir.0.033910-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
New insights into the early viral evolution and cellular immune response during acute hepatitis C virus (HCV) infection are being gained following a global outbreak in human immunodeficiency virus-1 (HIV)-positive men who have sex with men. Cross-sectional and longitudinal sequence analysis at both the population and individual level have facilitated tracking of the HCV epidemic across the world and enabled the development of tests of viral diversity in individual patients in order to predict spontaneous clearance of HCV and response to treatment. Immunological studies in HIV-positive cohorts have highlighted the role of the CD4+ T-cell response in the control of early HCV infection and will increase the opportunity for the identification of protective epitopes that could be used in future vaccine development.
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Affiliation(s)
- Emma C Thomson
- Department of Hepatology, Imperial College London, Norfolk Place, London W2 1PG, UK.,Peter Medawar Building for Pathogen Research, University of Oxford, South Parks Road, Oxford OX1 3SY, UK
| | - Jennifer A Smith
- Peter Medawar Building for Pathogen Research, University of Oxford, South Parks Road, Oxford OX1 3SY, UK
| | - Paul Klenerman
- Peter Medawar Building for Pathogen Research, University of Oxford, South Parks Road, Oxford OX1 3SY, UK
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58
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Scavenger receptor class B type I and the hypervariable region-1 of hepatitis C virus in cell entry and neutralisation. Expert Rev Mol Med 2011; 13:e13. [PMID: 21489334 DOI: 10.1017/s1462399411001785] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus (HCV) infection is a leading cause of chronic liver disease worldwide and represents a major public health problem. Viral attachment and entry - the first encounter of the virus with the host cell - are major targets of neutralising immune responses. Thus, a detailed understanding of the HCV entry process offers interesting opportunities for the development of novel therapeutic strategies. Different cellular or soluble host factors mediate HCV entry, and considerable progress has been made in recent years to decipher how they induce HCV attachment, internalisation and membrane fusion. Among these factors, the scavenger receptor class B type I (SR-BI/SCARB1) is essential for HCV replication in vitro, through its interaction with the HCV E1E2 surface glycoproteins and, more particularly, the HVR1 segment located in the E2 protein. SR-BI is an interesting receptor because HCV, whose replication cycle intersects with lipoprotein metabolism, seems to exploit some aspects of its physiological functions, such as cholesterol transfer from high-density lipoprotein (HDL), during cell entry. SR-BI is also involved in neutralisation attenuation and therefore could be an important target for therapeutic intervention. Recent results suggest that it should be possible to identify inhibitors of the interaction of HCV with SR-BI that do not impair its important physiological properties, as discussed in this review.
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Merz A, Long G, Hiet MS, Brügger B, Chlanda P, Andre P, Wieland F, Krijnse-Locker J, Bartenschlager R. Biochemical and morphological properties of hepatitis C virus particles and determination of their lipidome. J Biol Chem 2010; 286:3018-32. [PMID: 21056986 DOI: 10.1074/jbc.m110.175018] [Citation(s) in RCA: 281] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A hallmark of hepatitis C virus (HCV) particles is their association with host cell lipids, most notably lipoprotein components. It is thought that this property accounts for the low density of virus particles and their large heterogeneity. However, the composition of infectious virions and their biochemical and morphological properties are largely unknown. We developed a system in which the envelope glycoprotein E2 was N-terminally tagged with a FLAG epitope. This virus, designated Jc1E2(FLAG), produced infectivity titers to wild type levels and allowed affinity purification of virus particles that were analyzed for their protein and lipid composition. By using mass spectrometry, we found the lipid composition of Jc1E2(FLAG) particles to resemble the one very low- and low density-lipoprotein with cholesteryl esters accounting for almost half of the total HCV lipids. Thus, HCV particles possess a unique lipid composition that is very distinct from all other viruses analyzed so far and from the human liver cells in which HCV was produced. By electron microscopy (EM), we found purified Jc1E2(FLAG) particles to be heterogeneous, mostly spherical structures, with an average diameter of about 73 nm. Importantly, the majority of E2-containing particles also contained apoE on their surface as assessed by immuno-EM. Taken together, we describe a rapid and efficient system for the production of large quantities of affinity-purified HCV allowing a comprehensive analysis of the infectious virion, including the determination of its lipid composition.
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Affiliation(s)
- Andreas Merz
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
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