Serum levels of IgG to the peptide of HCV1b core at positions 35–44 correlated with persistent infection, while levels of IgG to the peptide of NS5A at positions 2132–2140 correlated with better prognosis in HCV-infected patients

Takao, Yukari; Yamada, Akira; Yutani, Shigeru; Ono, Takeharu; Nagao, Yumiko; Ando, Eiji; Ide, Tatsuya; Itoh, Kyogo; Sata, Michio

doi:10.1007/s00430-007-0038-1

Cited by 2 publications

(2 citation statements)

References 21 publications

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“…Based on published data about anti-HCV antibodies in serum (Desombere, et al 2007, Takao, et al 2007, Gabrielli, et al 1996, Zhang, et al 1995), we reasoned that the titer and profile of anti-HCV antibodies in ascitic fluid were likely to vary from patient-to-patient. Indirect ELISAs were used to identify ascitic fluid samples with high titers of antibodies against three HCV peptides: Core-2, NS4B, and NS5A.…”

Section: Resultsmentioning

confidence: 99%

Cross-genotypic polyclonal anti-HCV antibodies from human ascitic fluid

Gutiérrez¹,

Klepper²,

Garber³

et al. 2011

Journal of Virological Methods

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Many anti-HCV antibodies are available, but more are needed for research and clinical applications. This study examines whether ascitic fluid from cirrhotic patients could be a source of reagent-grade antibodies. Ascitic fluid from 29 HCV patients was screened by ELISA for anti-HCV antibodies against three viral proteins: core, NS4B, and NS5A. Significant patient-to-patient variability in anti-HCV antibody titers was observed. Total ascitic fluid IgG purified by Protein-A chromatography reacted with HCV proteins in immunoblots, cell extracts, and replicon-expressing cells. Affinity-purification using synthetic peptides as bait allowed the preparation of crossgenotypic antibodies directed against pre-selected regions of HCV core, NS4B, and NS5A proteins. The performance of the polyclonal antibodies was comparable to that of monoclonal antibodies. Anti-NS4B antibody preparations reacted with genotype 1a, 1b, and 2a NS4B proteins in immunoblots and allowed NS4B to be localized in replicon-expressing cells. Summary: Ascitic fluid is an abundant source of human polyclonal cross-genotypic antibodies that can be used as an alternative to blood. This study shows the utility of selectively-purifying human polyclonal antibodies from ascitic fluid. Affinity purification allows antibodies to be selected that are comparable to monoclonal antibodies in their ability to react with targeted regions of viral proteins.

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Section: Resultsmentioning

confidence: 99%

Cross-genotypic polyclonal anti-HCV antibodies from human ascitic fluid

Gutiérrez¹,

Klepper²,

Garber³

et al. 2011

Journal of Virological Methods

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show abstract

“…HCV often causes a prolonged and persistent infection (2) and plays an important role in the pathogenesis of virus-associated hepatocellular carcinoma (HCC) (3)(4)(5). The current hypothesis is that HCV-associated HCC may be resulted from immune-mediated inflammatory damage and cirrhosis.…”

Section: Hepatitis C Virus (Hcv)mentioning

confidence: 99%

Hepatitis C Virus NS5A Protein Down-regulates the Expression of Spindle Gene Aspm through PKR-p38 Signaling Pathway

Chang

et al. 2008

Journal of Biological Chemistry

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Hepatitis C virus often causes persistent infection and hepatocellular carcinoma. Studies have demonstrated the roles of viral nonstructural protein 5A (NS5A) in the induction of chromosome aneuploidy, but the molecular mechanisms are not clear. In this study, hydrodynamics-based in vivo transfection was applied to a mouse system. Mouse hepatocytes that successfully expressed NS5A protein were isolated by laser capture microdissection. Gene expression profiles of the NS5A-expressing hepatocytes were examined by an Affymetrix oligonucleotide microarray system. Aspm (abnormal spindle-like, microcephaly associated), which encodes the mitotic spindle protein ASPM, was identified to be differentially expressed in the absence and the presence of NS5A. The down-regulation of Aspm mRNA and ASPM protein was confirmed by real time polymerase chain reaction and Western blot analysis, respectively, both in mouse model systems and in viral subgenomic replicon and in vitro transfection culturing systems. In addition, cultured cells that constitutively expressed NS5A protein showed G 2 /M cell cycle block and chromosome aneuploidy. Overexpression of ASPM relieved the G 2 /M cell cycle block. Furthermore, NS5A protein repressed the promoter activity of Aspm gene in a dose-dependent manner. The regulatory effect was abolished when amino acid substitutions P2209L, T2214A, and T2217G known to interrupt the NS5A-PKR interaction were introduced into the NS5A protein. This indicates that the down-regulation of Aspm expression is via the PKR-p38 signaling pathway. These results suggest that NS5A protein downregulates the expression of the mitotic spindle protein ASPM and induces aberrant mitotic cell cycle associated with chromosome instability and hepatocellular carcinoma.

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Serum levels of IgG to the peptide of HCV1b core at positions 35–44 correlated with persistent infection, while levels of IgG to the peptide of NS5A at positions 2132–2140 correlated with better prognosis in HCV-infected patients

Cited by 2 publications

References 21 publications

Cross-genotypic polyclonal anti-HCV antibodies from human ascitic fluid

Cross-genotypic polyclonal anti-HCV antibodies from human ascitic fluid

Hepatitis C Virus NS5A Protein Down-regulates the Expression of Spindle Gene Aspm through PKR-p38 Signaling Pathway

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