Identification of hepatitis C virus-specific cytotoxicity T lymphocyte epitopes / 中华微生物学和免疫学杂志

ABSTRACT

Objective To identify hepatitis C virus(HCV)-specific cytotoxicity T lymphocytes (CTL)epitopes by the combination of T epitopes prediction software and in vitro assays.Methods HCVspecific CTL epitopes were predicted by T epitope prediction software Rankpep and then candidate HCV-specific CTL epitopes were selected.Candidate HCV-specific CTL epitopes were used to stimulate PBMC of HCV-infected patients and healthy volunteers.and then enzyme-linked immunospot(ELISPOT)and intracellular cytokine staining(ICS)were used to measure the frequencies of IFN-γ-producing cells in total PBMC and the percentages of IFN-γ+CD8+T cells in total CD8+T cells,respectively.Results Five candidate CTL epitopes[NS3 450(TVPQDAVSR),NS3 594(GPTLLYRL),Ns4b 78(sMMAFSAAL),NS5a 416(SEENVSVVF)and NS5a 367(TVSSALAEL)]were used to stimulate PBMC of ten HCV-infected patients and two healthy volunteers.PBMC of seven HCV-infected patients secreted IFN-γ while PBMC of healthy volunteers did not produce IFN-γ.The frequencies of peptide-specific IFN-γ-producing cells ranged from 5 to 36 SFC/105 PBMC and the percentages of peptide-specific IFN-γ+CD8+T cells ranged from 0.02%-0.25%.Conclusion Resuhs of ELISPOT assay and ICS assay confirm that these five peptides NS3 450,NS3 594,NS4b 78,NS5a 416 and NS5a 367 are identified as Hovel HCV-specific CTL epitopes.