scholarly journals The Hypervariable Region 1 of the E2 Glycoprotein of Hepatitis C Virus Binds to Glycosaminoglycans, but This Binding Does Not Lead to Infection in a Pseudotype System

2004 ◽  
Vol 78 (9) ◽  
pp. 4478-4486 ◽  
Author(s):  
Arnab Basu ◽  
Aster Beyene ◽  
Keith Meyer ◽  
Ranjit Ray
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Cell Surface ◽  
Hypervariable Region ◽  
Stable Cell Line ◽  
Enzyme Linked Immunosorbent Assay ◽  
E2 Glycoprotein ◽  
Hypervariable Region 1 ◽  
Pseudotype Virus ◽  
Hvr1 Sequence

ABSTRACT The hypervariable region 1 (HVR1) of hepatitis C virus (HCV) E2 envelope glycoprotein is a 27-amino-acid sequence located at its N terminus. In this study, we investigated the functional role of HVR1 for interaction with the mammalian cell surface. The C-terminal truncated E2 glycoprotein was appended to a transmembrane domain and cytoplasmic tail of vesicular stomatitis virus (VSV) G protein for generation of the chimeric E2-G gene construct. A deletion of the HVR1 sequence from E2 was created for the construction of E2ΔHVR1-G. Pseudotype virus, generated separately by infection of a stable cell line expressing E2-G or E2ΔHVR1-G with a temperature-sensitive mutant of VSV (VSVts045), displayed unique functional properties compared to VSVts045 as a negative control. Virus generated from E2ΔHVR1-G had a reduced plaquing efficiency (∼50%) in HepG2 cells compared to that for the E2-G virus. Cells prior treated with pronase (0.5 U/ml) displayed a complete inhibition of infectivity of the E2ΔHVR1-G or E2-G pseudotypes, whereas heparinase I treatment (8 U/ml) of cells reduced 40% E2-G pseudotype virus titer only. E2ΔHVR1-G pseudotypes were not sensitive to heparin (6 to 50 μg/ml) as an inhibitor of plaque formation compared to the E2-G pseudotype virus. Although the HVR1 sequence itself does not match with the known heparin-binding domain, a synthetic peptide representing 27 amino acids of the E2 HVR1 displayed a strong affinity for heparin in an enzyme-linked immunosorbent assay. This binding was competitively inhibited by a peptide from the V3 loop of a human immunodeficiency virus glycoprotein subunit (gp120) known to bind with cell surface heparin. Taken together, our results suggest that the HVR1 of E2 glycoprotein binds to the cell surface proteoglycans and may facilitate virus-host interaction for replication cycle of HCV.

scholarly journals An Interplay between Hypervariable Region 1 of the Hepatitis C Virus E2 Glycoprotein, the Scavenger Receptor BI, and High-Density Lipoprotein Promotes both Enhancement of Infection and Protection against Neutralizing Antibodies

2005 ◽  
Vol 79 (13) ◽  
pp. 8217-8229 ◽  
Author(s):  
Birke Bartosch ◽  
Géraldine Verney ◽  
Marlène Dreux ◽  
Peggy Donot ◽  
Yoann Morice ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Scavenger Receptor ◽  
Hypervariable Region ◽  
Density Lipoprotein ◽  
Cell Entry ◽  
Scavenger Receptor Bi ◽  
E2 Glycoprotein ◽  
Hypervariable Region 1

ABSTRACT Hepatitis C virus (HCV) circulates in the bloodstream in different forms, including complexes with immunoglobulins and/or lipoproteins. To address the significance of such associations, we produced or treated HCV pseudoparticles (HCVpp), a valid model of HCV cell entry and its inhibition, with naïve or patient-derived sera. We demonstrate that infection of hepatocarcinoma cells by HCVpp is increased more than 10-fold by human serum factors, of which high-density lipoprotein (HDL) is a major component. Infection enhancement requires scavenger receptor BI, a molecule known to mediate HDL uptake into cells as well as HCVpp entry, and involves conserved amino acid positions in hypervariable region 1 (HVR1) of the E2 glycoprotein. Additionally, we show that the interaction with human serum or HDL, but not with low-density lipoprotein, leads to the protection of HCVpp from neutralizing antibodies, including monoclonal antibodies and antibodies present in patient sera. Finally, the deletion or mutation of HVR1 in HCVpp abolishes infection enhancement and leads to increased sensitivity to neutralizing antibodies/sera compared to that of parental HCVpp. Altogether, these results assign to HVR1 new roles which are complementary in helping HCV to survive within its host. Besides immune escape by mutation, HRV1 can mediate the enhancement of cell entry and the protection of virions from neutralizing antibodies. By preserving a balance between these functions, HVR1 may be essential for the viral persistence of HCV.

scholarly journals A Recombinant Hepatitis C Virus Genotype 1a E1/E2 Envelope Glycoprotein Vaccine Elicits Antibodies That Differentially Neutralize Closely Related 2a Strains through Interactions of the N-Terminal Hypervariable Region 1 of E2 with Scavenger Receptor B1

2019 ◽  
Vol 93 (22) ◽  
Author(s):  
Janelle Johnson ◽  
Holly Freedman ◽  
Michael Logan ◽  
Jason Alexander Ji-Xhin Wong ◽  
Darren Hockman ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Scavenger Receptor ◽  
Hypervariable Region ◽  
Neutralization Sensitivity ◽  
Hcv Genotype ◽  
Hcv Genotypes ◽  
E2 Glycoprotein ◽  
Hypervariable Region 1

ABSTRACT The global health burden for hepatitis C virus (HCV) remains high, despite available effective treatments. To eliminate HCV, a prophylactic vaccine is needed. One major challenge in the development of a vaccine is the genetic diversity of the virus, with 7 major genotypes and many subtypes. A global vaccine must be effective against all HCV genotypes. Our previous data showed that the 1a E1/E2 glycoprotein vaccine component elicits broad cross-neutralizing antibodies in humans and animals. However, some variation is seen in the effectiveness of these antibodies to neutralize different HCV genotypes and isolates. Of interest was the differences in neutralizing activity against two closely related isolates of HCV genotype 2a, the J6 and JFH-1 strains. Using site-directed mutagenesis to generate chimeric viruses between the J6 and JFH-1 strains, we found that variant amino acids within the core E2 glycoprotein domain of these two HCV genotype 2a viruses do not influence isolate-specific neutralization. Further analysis revealed that the N-terminal hypervariable region 1 (HVR1) of the E2 protein determines the sensitivity of isolate-specific neutralization, and the HVR1 of the resistant J6 strain binds scavenger receptor class-B type-1 (SR-B1), while the sensitive JFH-1 strain does not. Our data provide new information on mechanisms of isolate-specific neutralization to facilitate the optimization of a much-needed HCV vaccine. IMPORTANCE A vaccine is still urgently needed to overcome the hepatitis C virus (HCV) epidemic. It is estimated that 1.75 million new HCV infections occur each year, many of which will go undiagnosed and untreated. Untreated HCV can lead to continued spread of the disease, progressive liver fibrosis, cirrhosis, and eventually, end-stage liver disease and/or hepatocellular carcinoma (HCC). Previously, our 1a E1/E2 glycoprotein vaccine was shown to elicit broadly cross-neutralizing antibodies; however, there remains variation in the effectiveness of these antibodies against different HCV genotypes. In this study, we investigated determinants of differential neutralization sensitivity between two highly related genotype 2a isolates, J6 and JFH-1. Our data indicate that the HVR1 region determines neutralization sensitivity to vaccine antisera through modulation of sensitivity to antibodies and interactions with SR-B1. Our results provide additional insight into optimizing a broadly neutralizing HCV vaccine.

scholarly journals Hypervariable region 1 variant acting as TCR antagonist affects hepatitis C virus-specific CD4+T cell repertoire by favoring CD95-mediated apoptosis

2005 ◽  
Vol 78 (2) ◽  
pp. 372-382 ◽  
Author(s):  
Cristiano Scottà ◽  
Loretta Tuosto ◽  
Anna Maria Masci ◽  
Luigi Racioppi ◽  
Enza Piccolella ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Hypervariable Region ◽  
Cd4 T Cell ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
Hypervariable Region 1

scholarly journals Ultradeep Pyrosequencing of Hepatitis C Virus Hypervariable Region 1 in Quasispecies Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Kamila Caraballo Cortés ◽  
Osvaldo Zagordi ◽  
Tomasz Laskus ◽  
Rafał Płoski ◽  
Iwona Bukowska-Ośko ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hypervariable Region ◽  
454 Sequencing ◽  
Correction Method ◽  
Sequencing Error ◽  
Hypervariable Region 1 ◽  
Reconstruction Methods ◽  
Sequencing Strategy

Genetic variability of hepatitis C virus (HCV) determines pathogenesis of infection, including viral persistence and resistance to treatment. The aim of the present study was to characterize HCV genetic heterogeneity within a hypervariable region 1 (HVR1) of a chronically infected patient by ultradeep 454 sequencing strategy. Three independent sequencing error correction methods were applied. First correction method (Method I) implemented cut-off for genetic variants present in less than 1%. In the second method (Method II), a condition to call a variant was bidirectional coverage of sequencing reads. Third method (Method III) usedShort Read Assembly into Haplotypes(ShoRAH) program. After the application of these three different algorithms, HVR1 population consisted of 8, 40, and 186 genetic haplotypes. The most sensitive method was ShoRAH, allowing to reconstruct haplotypes constituting as little as 0.013% of the population. The most abundant genetic variant constituted only 10.5%. Seventeen haplotypes were present in a frequency above 1%, and there was wide dispersion of the population into very sparse haplotypes. Our results indicate that HCV HVR1 heterogeneity andquasispeciespopulation structure may be reconstructed by ultradeep sequencing. However, credible analysis requires proper reconstruction methods, which would distinguish sequencing error from real variabilityin vivo.

scholarly journals Production and Characterization of Monoclonal Antibodies Specific for a Conserved Epitope within Hepatitis C Virus Hypervariable Region 1

2001 ◽  
Vol 75 (24) ◽  
pp. 12412-12420 ◽  
Author(s):  
Chengyao Li ◽  
Daniel Candotti ◽  
Jean-Pierre Allain
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Hypervariable Region ◽  
Passive Immunization ◽  
Immune Recognition ◽  
Hypervariable Region 1 ◽  
Neutralizing Capacity ◽  
Conserved Epitope

ABSTRACT Frequent mutations in hypervariable region 1 (HVR1) of the main envelope protein of hepatitis C virus (HCV) is a major mechanism of persistence by escaping the host immune recognition. HVR1 contains an epitope eliciting neutralizing antibodies. This study was aimed to prepare broadly cross-reacting, high-affinity, monoclonal antibodies (MAb) to the HVR1 C terminus of HCV with potential therapeutic neutralizing capacity. A conserved amino residue group of glycine (G) at position 23 and glutamic acid (Q) at position 26 in HVR1 was confirmed as a key epitope against which two MAbs were selected and characterized. MAbs 2P24 and 15H4 were immunoglobulin G1 kappa chain [IgG1(κ)], cross-reacted with 32 and 30 of 39 random C-terminal HVR1 peptides, respectively, and did not react with other HCV peptides. The VH of 2P24 and 15H4 heavy chains originated from Igh germ line v gene family 1 and 8, respectively. In contrast, the VL κ sequences were highly homologous. The affinity (K d ) of 2P24 and 15H4 (10−9 or 10−8 M with two immunizing peptides and 10−8 M with two nonimmunizing HVR1 peptides) paralleled the reactivity obtained with peptide enzyme immunoassay. MAbs 2P24 and 15H4 captured 25 of 31 (81%) HCV in unselected patients' plasmas. These antibodies also blocked HCV binding to Molt-4 cells in a dose-dependent fashion. The data presented suggest that broadly cross-reactive MAbs to a conserved epitope within HCV HVR1 can be produced. Clinical application for passive immunization in HCV-related chronic liver disease and after liver transplantation is considered.

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