PLoS ONE (Jan 2010)

Characterization of the specific CD4+ T cell response against the F protein during chronic hepatitis C virus infection.

  • De-Yong Gao,
  • Gen-Di Jin,
  • Bi-Lian Yao,
  • Dong-Hua Zhang,
  • Lei-Lei Gu,
  • Zhi-Meng Lu,
  • Qiming Gong,
  • Yu-Chun Lone,
  • Qiang Deng,
  • Xin-Xin Zhang

DOI
https://doi.org/10.1371/journal.pone.0014237
Journal volume & issue
Vol. 5, no. 12
p. e14237

Abstract

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BACKGROUND: The hepatitis C virus (HCV) Alternate Reading Frame Protein (ARFP or F protein) presents a double-frame shift product of the HCV core gene. We and others have previously reported that the specific antibodies against the F protein could be raised in the sera of HCV chronically infected patients. However, the specific CD4(+) T cell responses against the F protein during HCV infection and the pathological implications remained unclear. In the current study, we screened the MHC class II-presenting epitopes of the F protein through HLA-transgenic mouse models and eventually validated the specific CD4(+) T cell responses in HCV chronically infected patients. METHODOLOGY: DNA vaccination in HLA-DR1 and-DP4 transgenic mouse models, proliferation assay to test the F protein specific T cell response, genotyping of Chronic HCV patients and testing the F-peptide stimulated T cell response in the peripheral blood mononuclear cell (PBMC) by in vitro expansion and interferon (IFN)- γ intracellular staining. PRINCIPAL FINDINGS: At least three peptides within HCV F protein were identified as HLA-DR or HLA-DP4 presenting epitopes by the proliferation assays in mouse models. Further study with human PBMCs evidenced the specific CD4(+) T cell responses against HCV F protein as well in patients chronically infected with HCV. CONCLUSION: The current study provided the evidence for the first time that HCV F protein could elicit specific CD4(+) T cell response, which may provide an insight into the immunopathogenesis during HCV chronic infection.