Genetic organization and diversity of the hepatitis C virus.

Choo, Qui‐Lim; Richman, K H; Han, Jang H.; Berger, Kimberly; Lee, C; Dong, Christine; Gallegos, Carmen; Coit, Doris; Medina-Selby, R; Barr, Philip J.

doi:10.1073/pnas.88.6.2451

Cited by 1,557 publications

(1,044 citation statements)

References 25 publications

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“…The coNS3/4A gene had a sequence homology of 79% with the region at nucleotide positions 3417-5475 of the HCV-1 reference strain. 46 A total of 433 nucleotides differed. On an amino-acid level, the homology with the HCV-1 strain was 98% (15 amino acids differed).…”

Section: Synthetic Peptidesmentioning

confidence: 99%

Codon optimization and mRNA amplification effectively enhances the immunogenicity of the hepatitis C virus nonstructural 3/4A gene

et al. 2004

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We have recently shown that the NS3-based genetic immunogens should contain also hepatitis C virus (HCV) nonstructural (NS) 4A to utilize fully the immunogenicity of NS3. The next step was to try to enhance immunogenicity by modifying translation or mRNA synthesis. To enhance translation efficiency, a synthetic NS3/4A-based DNA (coNS3/4A-DNA) vaccine was generated in which the codon usage was optimized (co) for human cells. In a second approach, expression of the wild-type (wt) NS3/4A gene was enhanced by mRNA amplification using the Semliki forest virus (SFV) replicon (wtNS3/4A-SFV). Transient tranfections of human HepG2 cells showed that the coNS3/4A gene gave 11-fold higher levels of NS3 as compared to the wtNS3/4A gene when using the CMV promoter. We have previously shown that the presence of NS4A enhances the expression by SFV. Both codon optimization and mRNA amplification resulted in an improved immunogenicity as evidenced by higher levels of NS3-specific antibodies. This improved immunogenicity also resulted in a more rapid priming of cytotoxic T lymphocytes (CTLs). Since HCV is a noncytolytic virus, the functionality of the primed CTL responses was evaluated by an in vivo challenge with NS3/4A-expressing syngeneic tumor cells. The priming of a tumor protective immunity required an endogenous production of the immunogen and CD8 þ CTLs, but was independent of B and CD4 þ T cells. This model confirmed the more rapid in vivo activation of an NS3/4A-specific tumor-inhibiting immunity by codon optimization and mRNA amplification. Finally, therapeutic vaccination with the coNS3/4A gene using gene gun 6-12 days after injection of tumors significantly reduced the tumor growth in vivo. Codon optimization and mRNA amplification effectively enhances the overall immunogenicity of NS3/4A. Thus, either, or both, of these approaches should be utilized in an NS3/4A-based HCV genetic vaccine.

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Section: Synthetic Peptidesmentioning

confidence: 99%

Codon optimization and mRNA amplification effectively enhances the immunogenicity of the hepatitis C virus nonstructural 3/4A gene

et al. 2004

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“…To study the biosyncontrol. 1,5,6 The coding region encodes structural proteins in thesis of HCV structural proteins and their pathogenic its N-terminal portion that include a nonglycosylated core role, we constructed transgenic mice, expressing type protein (p22), which associates with genomic RNA to form 1b HCV structural proteins (core, E1, and E2) in liver the nucleocapsid. The C-terminal 20 amino acids of the core tissues.…”

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confidence: 99%

“…12 30% to 70% of patients Hepatitis C virus (HCV) contains a single 9.4 kb (/)-with hepatitis B virus (HBV)-negative HCC are seropositive stranded RNA genome, containing a single open reading for HCV, which in the United States may represent as many frame that encodes a polyprotein of 3,011 amino acids. 1,2 The as 40% of all cases of HCC. polyprotein is post-translationally processed to yield several Success in controlling HCV infection with antiviral agents mature structural and nonstructural proteins.…”

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confidence: 99%

Transgenic expression of hepatitis C virus structural proteins in the mouse

et al. 1997

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lies. 3,4 In general, the genome is flanked in its 5 -untranslated Although hepatitis C virus (HCV) is a leading cause region by a highly conserved (ú98%) 341 nucleotide seof morbidity and mortality worldwide, the role of viral quence, which appears to play a key role in translational cytopathic effects remains unclear. To study the biosyncontrol. 1,5,6 The coding region encodes structural proteins in thesis of HCV structural proteins and their pathogenic its N-terminal portion that include a nonglycosylated core role, we constructed transgenic mice, expressing type protein (p22), which associates with genomic RNA to form 1b HCV structural proteins (core, E1, and E2) in liver the nucleocapsid. The C-terminal 20 amino acids of the core tissues. Two liver-specific promoters were used. The protein are highly hydrophobic and may act as a signal semouse major urinary protein (MUP) promoter has been quence for processing of adjacent polypeptides. 7,8 Immedishown to be developmentally regulated with little or no ately downstream from the core are two proteins, designated expression in utero but high-level expression after birth.E1 and E2/NS1, which correspond to the putative envelope The albumin (Alb) promoter provides constitutive, high glycoproteins. These proteins, designated gp33 and gp70 levels of transgenes in liver. Expression of both HCV respectively, are extensively N-glycosylated and appear to transgenes was detected in several lines by Northern function as membrane-associated proteins essential for virion blots, HCV-specific reverse transcriptase-polymerase assembly. The presence of a hypervariable region in the Nchain reactions (RT-PCR), and Western immunoblotting.terminal portion of the E2/NS1 domain to which an active Alb HCV lines showed higher levels of HCV expression humoral response is directed in infected individuals suggests than the MUP HCV lines. Immunohistochemical analysis that this region is subjected to immune selection. 4,9 This rerevealed a predominantly cytoplasmic presence of core gion exhibits significant variation not only among HCV isoprotein with occasional nuclear staining, and both cytolates but also within infected individuals over the course of plasmic and membrane expression of the E2 protein in time. 10 the transgenic livers. In both transgenes, the highest lev-HCV is an important cause of morbidity and mortality els of both antigens were seen in perivenular hepatoworldwide, causing a spectrum of liver disease ranging from cytes, suggesting potential processing specificity in the asymptomatic carrier state to end-stage liver disease. those cells. At six months of age, the livers of allCompared to other hepatotropic viruses, there is a higher transgenic lineages remained histologically normal. We rate of chronicity after HCV infection, with at least 70% of concluded that HCV structural proteins are not directly those infected developing chronic liver disease. 11 In addition cytopathic in this animal model. (HEPATOLOGY 1997;25: to the morbidity and mortality caused by chronic l...

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“…HCV has a positivestranded RNA as its genome. Nucleotide sequence analyses of HCV clones isolated in different places in the world revealed that there are significant sequence diversities (8)(9)(10)(11)(12)(13)(14)(15). The analysis of the region of non-structure 5 (NS5) of the HCV genome found, at least five different HCV genotypes in the world (16).…”

Section: Introductionmentioning

confidence: 99%