Strain-dependent viral dynamics and virus-cell interactions in a novel in vitro system supporting the life cycle of blood-borne hepatitis C virus #

Aly, Hussein Hassan; Qi, Yue; Atsuzawa, Kimie; Usuda, Nobuteru; Takada, Yasutsugu; Mizokami, Masashi; Shimotohno, Kunitada; Hijikata, Makoto

doi:10.1002/hep.23034

Cited by 17 publications

(21 citation statements)

References 30 publications

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“…Several reports have shown that disulfide bonds in the capsid proteins of some viruses are involved in virus particle assembly and stabilization of the viral capsid structure (4,21,27,28,57); these viruses are characterized by icosahedral nucleocapsids. Because, like these viruses, the HCV virion is spherical (2,20), it has been suggested that HCV may contain a nucleocapsid with a similar structure (20). We found the dbc-complex, which is most likely to be the dbd-core in JFH1 E2FL virus-like particles ( Fig.…”

Section: Discussionmentioning

confidence: 72%

A Disulfide-Bonded Dimer of the Core Protein of Hepatitis C Virus Is Important for Virus-Like Particle Production

Kushima

Wakita

Hijikata

2010

J Virol

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Hepatitis C virus (HCV) core protein forms the nucleocapsid of the HCV particle. Although many functions of core protein have been reported, how the HCV particle is assembled is not well understood. Here we show that the nucleocapsid-like particle of HCV is composed of a disulfide-bonded core protein complex (dbccomplex). We also found that the disulfide-bonded dimer of the core protein (dbd-core) is formed at the endoplasmic reticulum (ER), where the core protein is initially produced and processed. Mutational analysis revealed that the cysteine residue at amino acid position 128 (Cys128) of the core protein, a highly conserved residue among almost all reported isolates, is responsible for dbd-core formation and virus-like particle production but has no effect on the replication of the HCV RNA genome or the several known functions of the core protein, including RNA binding ability and localization to the lipid droplet. The Cys128 mutant core protein showed a dominant negative effect in terms of HCV-like particle production. These results suggest that this disulfide bond is critical for the HCV virion. We also obtained the results that the dbc-complex in the nucleocapsid-like structure was sensitive to proteinase K but not trypsin digestion, suggesting that the capsid is built up of a tightly packed structure of the core protein, with its amino (N)-terminal arginine-rich region being concealed inside.

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Section: Discussionmentioning

confidence: 72%

A Disulfide-Bonded Dimer of the Core Protein of Hepatitis C Virus Is Important for Virus-Like Particle Production

Kushima

Wakita

Hijikata

2010

J Virol

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“…Immortalized human primary hepatocyte HuS-E/2 cells were as described previously (17). Other cells and plasmids used in this experiment are summarized in SI Materials and Methods.…”

Section: Methodsmentioning

confidence: 99%

MicroRNA-33 encoded by an intron of sterol regulatory element-binding protein 2 ( Srebp2 ) regulates HDL in vivo

Horie

Ono²,

Horiguchi³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

357

328

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Sterol regulatory element-binding protein 2 (SREBP-2) transcription factor has been identified as a key protein in cholesterol metabolism through the transactivation of the LDL receptor and cholesterol biosynthesis genes. Here, we generated mice lacking microRNA (miR)-33, encoded by an intron of the Srebp2, and showed that miR-33 repressed the expression of ATP-binding cassette transporter A1 (ABCA1) protein, a key regulator of HDL synthesis by mediating cholesterol efflux from cells to apolipoprotein A (apoA)-I. In fact, peritoneal macrophages derived from miR-33-deficient mice showed a marked increase in ABCA1 levels and higher apoA-I-dependent cholesterol efflux than those from WT mice. ABCA1 protein levels in liver were also higher in miR-33-deficient mice than in WT mice. Moreover, miR-33-deficient mice had significantly higher serum HDL cholesterol levels than WT mice. These data establish a critical role for miR-33 in the regulation of ABCA1 expression and HDL biogenesis in vivo.A TP-binding cassette transporter A1 (ABCA1), a 254-kDa cytoplasmic membrane protein, is a pivotal regulator of lipid efflux from cells to apolipoproteins (1). ABCA1 mediates the ratecontrolling step in HDL particle formation and plays an important role in reverse cholesterol transfer (2, 3). Mutations in the ABCA1 gene cause Tangier disease, which is characterized by the near absence of plasma HDL cholesterol associated with storage of cholesterol esters in reticuloendothelial tissues (4-7). Abca1 mRNA and protein are very unstable, with a half life of 1-2 h in murine macrophages (8), which indicates that new transcription and translation are major factors in ensuring constant and inducible ABCA1 expression.Sterol regulatory element-binding proteins (SREBPs), including SREBP-1a, -1c, and -2, modulate the transcription of a number of genes involved in the synthesis and receptor-mediated uptake of cholesterol and fatty acids (9-11). In sterol-depleted cells, SREBPs are cleaved by proteases in the Golgi, releasing the N-termini, which translocate into the nucleus and bind to SREs in the enhancers of multiple genes encoding enzymes and proteins involved in cholesterol biosynthesis and lipid uptake (11-13). Results to date support the notion that SREBP-1 primarily activates the fatty acid triglyceride and phospholipid pathways, whereas SREBP-2 is the prominent isoform for cholesterol synthesis and uptake (9,10,12).MicroRNAs (miRs) are small, non-protein-coding RNAs that base pair with specific mRNAs and inhibit translation or promote mRNA degradation. Recent reports have indicated that miR-33 controls cholesterol homeostasis based on knockdown experiments using antisense technology (14-16). Antisense inhibition of miRNA function has been an important tool for elucidating miRNA biology. However, to determine the potential developmental function of specific miRNAs and to perform longer-term studies, it is necessary to generate mice lacking each miRNA. We generated miR-33-deficient mice, which were born at the expected Mendelian ratio, a...

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“…Early evidence of productive HCV infection in culture came from the use of a human hepatocellular carcinoma–derived line (FLC4) cultured in 3D radial-flow bioreactors (108). More recently, Aly and coworkers demonstrated that HCV replication was increased in immortalized primary hepatocytes cultured in a 3D thermoreversible gelatin polymer (TGP) system (109) and that viral particle production was achieved upon challenge with HCV gt1b and gt2a (110) when these cells were cultured in a 3D hollow fiber system (111). Like the TGP system, the hollow fiber reactor is smaller scale than the radial-flow bioreactor, allowing easy access to both medium and cells for virological assessment.…”

Section: Hepatotropic Virus Infection In Models With Emergent Propertiesmentioning

confidence: 99%

New Methods in Tissue Engineering: Improved Models for Viral Infection

et al. 2014

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New insights in the study of virus and host biology in the context of viral infection are made possible by the development of model systems that faithfully recapitulate the in vivo viral life cycle. Standard tissue culture models lack critical emergent properties driven by cellular organization and in vivo–like function, whereas animal models suffer from limited susceptibility to relevant human viruses and make it difficult to perform detailed molecular manipulation and analysis. Tissue engineering techniques may enable virologists to create infection models that combine the facile manipulation and readouts of tissue culture with the virus-relevant complexity of animal models. Here, we review the state of the art in tissue engineering and describe how tissue engineering techniques may alleviate some common shortcomings of existing models of viral infection, with a particular emphasis on hepatotropic viruses. We then discuss possible future applications of tissue engineering to virology, including current challenges and potential solutions.

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Strain-dependent viral dynamics and virus-cell interactions in a novel in vitro system supporting the life cycle of blood-borne hepatitis C virus #

Cited by 17 publications

References 30 publications

A Disulfide-Bonded Dimer of the Core Protein of Hepatitis C Virus Is Important for Virus-Like Particle Production

A Disulfide-Bonded Dimer of the Core Protein of Hepatitis C Virus Is Important for Virus-Like Particle Production

MicroRNA-33 encoded by an intron of sterol regulatory element-binding protein 2 ( Srebp2 ) regulates HDL in vivo

New Methods in Tissue Engineering: Improved Models for Viral Infection

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