Interfering with hepatitis C virus assembly in vitro using affinity peptides directed towards core protein

2012 ◽  
Vol 58 (4) ◽  
pp. 475-482
Author(s):  
Jean-Baptiste Duvignaud ◽  
Nathalie Majeau ◽  
Priscilla Delisle ◽  
Normand Voyer ◽  
Stéphane M. Gagné ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Self Assembly ◽  
Core Protein ◽  
Virus Assembly ◽  
Viral Assembly ◽  
Structural Protein ◽  
Ns5a Protein ◽  
The Core

Viral assembly is a crucial key step in the life cycle of every virus. In the case of Hepatitis C virus (HCV), the core protein is the only structural protein to interact directly with the viral genomic RNA. Purified recombinant core protein is able to self-assemble in vitro into nucleocapsid-like particles upon addition of a structured RNA, providing a robust assay with which to study HCV assembly. Inhibition of self-assembly of the C170 core protein (first 170 amino acids) was tested using short peptides derived from the HCV core, from HCV NS5A protein, and from diverse proteins (p21 and p73) known to interact with HCV core protein. Interestingly, peptides derived from the core were the best inhibitors. These peptides are derived from regions of the core predicted to be involved in the interaction between core subunits during viral assembly. We also demonstrated that a peptide derived from the C-terminal end of NS5A protein moderately inhibits the assembly process.

scholarly journals Self-Assembly of Nucleocapsid-Like Particles from Recombinant Hepatitis C Virus Core Protein

2001 ◽  
Vol 75 (5) ◽  
pp. 2119-2129 ◽  
Author(s):  
Meghan Kunkel ◽  
Marta Lorinczi ◽  
René Rijnbrand ◽  
Stanley M. Lemon ◽  
Stanley J. Watowich
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Self Assembly ◽  
High Throughput Screening ◽  
Core Protein ◽  
Rna Molecules ◽  
The Core ◽  
Assembly Pathway ◽  
Core Proteins

ABSTRACT Little is known about the assembly pathway and structure of hepatitis C virus (HCV) since insufficient quantities of purified virus are available for detailed biophysical and structural studies. Here, we show that bacterially expressed HCV core proteins can efficiently self-assemble in vitro into nucleocapsid-like particles. These particles have a regular, spherical morphology with a modal distribution of diameters of approximately 60 nm. Self-assembly of nucleocapsid-like particles requires structured RNA molecules. The 124 N-terminal residues of the core protein are sufficient for self-assembly into nucleocapsid-like particles. Inclusion of the carboxy-terminal domain of the core protein modifies the core assembly pathway such that the resultant particles have an irregular outline. However, these particles are similar in size and shape to those assembled from the 124 N-terminal residues of the core protein. These results provide novel opportunities to delineate protein-protein and protein-RNA interactions critical for HCV assembly, to study the molecular details of HCV assembly, and for performing high-throughput screening of assembly inhibitors.

scholarly journals Virus assembly occurs following a pH- or Ca 2+ -triggered switch in the thermodynamic attraction between structural protein capsomeres

2009 ◽  
Vol 7 (44) ◽  
pp. 409-421 ◽  
Author(s):  
Yap P. Chuan ◽  
Yuan Y. Fan ◽  
Linda H. L. Lua ◽  
Anton P. J. Middelberg
Keyword(s):  
Self Assembly ◽  
Virus Assembly ◽  
Chemical Change ◽  
Second Virial Coefficient ◽  
Direct Proof ◽  
Viral Assembly ◽  
Structural Protein ◽  
Salting Out ◽  
Self Assembling

Viral self-assembly is of tremendous virological and biomedical importance. Although theoretical and crystallographic considerations suggest that controlled conformational change is a fundamental regulatory mechanism in viral assembly, direct proof that switching alters the thermodynamic attraction of self-assembling components has not been provided. Using the VP1 protein of polyomavirus, we report a new method to quantitatively measure molecular interactions under conditions of rapid protein self-assembly. We show, for the first time, that triggering virus capsid assembly through biologically relevant changes in Ca 2+ concentration, or pH, is associated with a dramatic increase in the strength of protein molecular attraction as quantified by the second virial coefficient ( B 22 ). B 22 decreases from −2.3 × 10 −4 mol ml g −2 (weak protein–protein attraction) to −2.4 × 10 −3 mol ml g −2 (strong protein attraction) for metastable and Ca 2+ -triggered self-assembling capsomeres, respectively. An assembly-deficient mutant (VP1CΔ63) is conversely characterized by weak protein–protein repulsion independently of chemical change sufficient to cause VP1 assembly. Concomitant switching of both VP1 assembly and thermodynamic attraction was also achieved by in vitro changes in ammonium sulphate concentration, consistent with protein salting-out behaviour. The methods and findings reported here provide new insight into viral assembly, potentially facilitating the development of new antivirals and vaccines, and will open the way to a more fundamental physico-chemical description of complex protein self-assembly systems.

scholarly journals The N-terminal half of the core protein of hepatitis C virus is sufficient for nucleocapsid formation

2004 ◽  
Vol 85 (4) ◽  
pp. 971-981 ◽  
Author(s):  
Nathalie Majeau ◽  
Valérie Gagné ◽  
Annie Boivin ◽  
Marilène Bolduc ◽  
Josée-Anne Majeau ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Host Cells ◽  
Yeast Cells ◽  
Main Function ◽  
C Protein ◽  
Multifunctional Protein ◽  
The Core

The core (C) protein of hepatitis C virus (HCV) appears to be a multifunctional protein that is involved in many viral and cellular processes. Although its effects on host cells have been extensively discussed in the literature, little is known about its main function, the assembly and packaging of the viral genome. We have studied the in vitro assembly of several deleted versions of recombinant HCV C protein expressed in E. coli. We demonstrated that the 75 N-terminal residues of the C protein were sufficient to assemble and generate nucleocapsid-like particles (NLPs) in vitro. However, homogeneous particles of regular size and shape were observed only when NLPs were produced from at least the first 79 N-terminal amino acids of the C protein. This small protein unit fused to the endoplasmic reticulum-anchoring domain also generated NLPs in yeast cells. These data suggest that the N-terminal half of the C protein is important for formation of NLPs. Similarities between the HCV C protein and C proteins of other members of the Flaviviridae are discussed.

scholarly journals Repression of Interferon Regulatory Factor 1 by Hepatitis C Virus Core Protein Results in Inhibition of Antiviral and Immunomodulatory Genes

2006 ◽  
Vol 81 (1) ◽  
pp. 202-214 ◽  
Author(s):  
Anna R. Ciccaglione ◽  
Emilia Stellacci ◽  
Cinzia Marcantonio ◽  
Valentina Muto ◽  
Michele Equestre ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Interferon Regulatory Factor ◽  
Structural Proteins ◽  
Transcriptional Level ◽  
Structural Protein ◽  
Regulatory Factor ◽  
The Core ◽  
Interferon Regulatory Factor 1

ABSTRACT Hepatitis C virus (HCV) proteins are known to interfere at several levels with both innate and adaptive responses of the host. A key target in these effects is the interferon (IFN) signaling pathway. While the effects of nonstructural proteins are well established, the role of structural proteins remains controversial. We investigated the effect of HCV structural proteins on the expression of interferon regulatory factor 1 (IRF-1), a secondary transcription factor of the IFN system responsible for inducing several key antiviral and immunomodulatory genes. We found substantial inhibition of IRF-1 expression in cells expressing the entire HCV replicon. Suppression of IRF-1 synthesis was mainly mediated by the core structural protein and occurred at the transcriptional level. The core protein in turn exerted a transcriptional repression of several interferon-stimulated genes, targets of IRF-1, including interleukin-15 (IL-15), IL-12, and low-molecular-mass polypeptide 2. These data recapitulate in a unifying mechanism, i.e., repression of IRF-1 expression, many previously described pathogenetic effects of HCV core protein and suggest that HCV core-induced IRF-1 repression may play a pivotal role in establishing persistent infection by dampening an effective immune response.

scholarly journals Hepatitis C Virus Core Protein Binds to the Cytoplasmic Domain of Tumor Necrosis Factor (TNF) Receptor 1 and Enhances TNF-Induced Apoptosis

1998 ◽  
Vol 72 (5) ◽  
pp. 3691-3697 ◽  
Author(s):  
Nongliao Zhu ◽  
Ali Khoshnan ◽  
Robert Schneider ◽  
Masayuki Matsumoto ◽  
Gunther Dennert ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Tumor Necrosis ◽  
Core Protein ◽  
Cytoplasmic Domain ◽  
The Core ◽  
Induced Apoptosis ◽  
Necrosis Factor

ABSTRACT The hepatitis C virus (HCV) core protein is known to be a multifunctional protein, besides being a component of viral nucleocapsids. Previously, we have shown that the core protein binds to the cytoplasmic domain of lymphotoxin β receptor, which is a member of tumor necrosis factor receptor (TNFR) family. In this study, we demonstrated that the core protein also binds to the cytoplasmic domain of TNFR 1. The interaction was demonstrated both by glutathioneS-transferase fusion protein pull-down assay in vitro and membrane flotation method in vivo. Both the in vivo and in vitro binding required amino acid residues 345 to 407 of TNFR 1, which corresponds to the “death domain” of this receptor. We have further shown that stable expression of the core protein in a mouse cell line (BC10ME) or human cell lines (HepG2 and HeLa cells) sensitized them to TNF-induced apoptosis, as determined by the TNF cytotoxicity or annexin V apoptosis assay. The presence of the core protein did not alter the level of TNFR 1 mRNA in the cells or expression of TNFR 1 on the cell surface, suggesting that the sensitization of cells to TNF by the viral core protein was not due to up-regulation of TNFR 1. Furthermore, we observed that the core protein blocked the TNF-induced activation of RelA/NF-κB in murine BC10ME cells, thus at least partially accounting for the increased sensitivity of BC10ME cells to TNF. However, NF-κB activation was not blocked in core protein-expressing HeLa or HepG2 cells, implying another mechanism of TNF sensitization by core protein. These results together suggest that the core protein can promote cell death during HCV infection via TNF signaling pathways possibly as a result of its interaction with the cytoplasmic tail of TNFR 1. Therefore, TNF may play a role in HCV pathogenesis.

scholarly journals Rab18 is required for viral assembly of hepatitis C virus through trafficking of the core protein to lipid droplets

Virology ◽  
2014 ◽  
Vol 462-463 ◽  
pp. 166-174 ◽  
Author(s):  
Hiromichi Dansako ◽  
Hiroki Hiramoto ◽  
Masanori Ikeda ◽  
Takaji Wakita ◽  
Nobuyuki Kato
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Lipid Droplets ◽  
Core Protein ◽  
Viral Assembly ◽  
The Core

scholarly journals The genotype 3-specific hepatitis C virus core protein residue phenylalanine 164 increases steatosis in an in vitro cellular model

Gut ◽  
2007 ◽  
Vol 56 (9) ◽  
pp. 1302-1308 ◽  
Author(s):  
C Hourioux ◽  
R Patient ◽  
A Morin ◽  
E Blanchard ◽  
A Moreau ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Cellular Model ◽  
Genotype 3 ◽  
Virus Core

scholarly journals Cytokine-Modulated Natural Killer Cells Differentially Regulate the Activity of the Hepatitis C Virus

2018 ◽  
Vol 19 (9) ◽  
pp. 2771 ◽  
Author(s):  
Yoo Cho ◽  
Hwan Lee ◽  
Hyojeung Kang ◽  
Hyosun Cho
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nk Cells ◽  
Natural Killer ◽  
Core Protein ◽  
Lymphoid Cells ◽  
Hcv Rna ◽  
Cell Infection ◽  
Hcv Core Protein

HCV genotype 2a strain JFH-1 replicates and produces viral particles efficiently in human hepatocellular carcinoma (huh) 7.5 cells, which provide a stable in vitro cell infection system for the hepatitis C virus (HCVcc system). Natural killer (NK) cells are large lymphoid cells that recognize and kill virus-infected cells. In this study, we investigated the interaction between NK cells and the HCVcc system. IL-10 is a typical immune regulatory cytokine that is produced mostly by NK cells and macrophages. IL-21 is one of the main cytokines that stimulate the activation of NK cells. First, we used anti-IL-10 to neutralize IL-10 in a coculture of NK cells and HCVcc. Anti-IL-10 treatment increased the maturation of NK cells by enhancing the frequency of the CD56+dim population in NK-92 cells. However, with anti-IL-10 treatment of NK cells in coculture with J6/JFH-1-huh 7.5 cells, there was a significant decrease in the expression of STAT1 and STAT5 proteins in NK-92 cells and an increase in the HCV Core and NS3 proteins. In addition, rIL-21 treatment increased the frequency of the CD56+dim population in NK-92 cells, Also, there was a dramatic increase in the expression of STAT1 and STAT5 proteins in rIL-21 pre-stimulated NK cells and a decrease in the expression of HCV Core protein in coculture with J6/JFH-1-huh 7.5 cells. In summary, we found that the functional activation of NK cells can be modulated by anti-IL-10 or rIL-21, which controls the expression of HCV proteins as well as HCV RNA replication.

scholarly journals Efficient Virus Assembly, but Not Infectivity, Determines the Magnitude of Hepatitis C Virus-Induced Interferon Alpha Responses of Plasmacytoid Dendritic Cells

2014 ◽  
Vol 89 (6) ◽  
pp. 3200-3208 ◽  
Author(s):  
Elena Grabski ◽  
Ilka Wappler ◽  
Stephanie Pfaender ◽  
Eike Steinmann ◽  
Sibylle Haid ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Virus Assembly ◽  
Plasmacytoid Dendritic Cells ◽  
Type I ◽  
Hepatitis C Virus Infection ◽  
Infected Cells ◽  
Interferon Responses

ABSTRACTWorldwide, approximately 160 million people are chronically infected with hepatitis C virus (HCV), seven distinct genotypes of which are discriminated. The hallmarks of HCV are its genetic variability and the divergent courses of hepatitis C progression in patients. We assessed whether intragenotypic HCV variations would differentially trigger host innate immunity. To this end, we stimulated human primary plasmacytoid dendritic cells (pDC) with crude preparations of different cell culture-derived genotype 2a HCV variants. Parental Japanese fulminant hepatitis C virus (JFH1) did not induce interferon alpha (IFN-α), whereas the intragenotypic chimera Jc1 triggered massive IFN-α responses. Purified Jc1 retained full infectivity but no longer induced IFN-α. Coculture of pDC with HCV-infected hepatoma cells retrieved the capacity to induce IFN-α, whereas Jc1-infected cells triggered stronger responses than JFH1-infected cells. Since the infectivity of virus particles did not seem to affect pDC activation, we next tested Jc1 mutants that were arrested at different stages of particle assembly. These experiments revealed that efficient assembly and core protein envelopment were critically needed to trigger IFN-α. Of note, sequences within domain 2 of the core that vitally affect virus assembly also crucially influenced the IFN-α responses of pDC. These data showed that viral determinants shaped host innate IFN-α responses to HCV.IMPORTANCEAlthough pegylated IFN-α plus ribavirin currently is the standard of care for the treatment of chronic hepatitis C virus infection, not much is known about the relevance of early interferon responses in the pathogenesis of hepatitis C virus infection. Here, we addressed whether intragenotypic variations of hepatitis C virus would account for differential induction of type I interferon responses mounted by primary blood-derived plasmacytoid dendritic cells. Surprisingly, a chimeric genotype 2a virus carrying the nonstructural genes of Japanese fulminant hepatitis C virus (JFH1) induced massive type I interferon responses, whereas the original genotype 2a JFH1 strain did not. Our detailed analyses revealed that, not the virus infectivity, but rather, the efficiency of virus assembly and core protein envelopment critically determined the magnitude of interferon responses. To our knowledge, this is the first example of hepatitis C virus-associated genetic variations that determine the magnitude of innate host responses.

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