Natural epitope variants of the hepatitis C virus impair cytotoxic T lymphocyte activity  

作　　者：Shuping Wang Rico Buchli Jennifer Schiller Jianen Gao Rodney S VanGundy William H Hildebrand David D Eckels 

机构地区：[1]Department of Pathology,University of Utah [2]Pure Protein L.L.C.,Oklahoma City,OK 73104,United States Jennifer Schiller,Jianen Gao,Department of Pediatrics,Medical College of Wisconsin [3]Department of Pediatrics,Medical College of Wisconsin [4]Pure Protein L.L.C. [5]Department of Microbiology and Immunology,Health Sciences Center,University of Oklahoma

出　　处：《World Journal of Gastroenterology》2010年第16期1953-1969,共17页世界胃肠病学杂志（英文版）

基　　金：Supported by The National Institutes of Health, No. NIH-DK-57732

摘　　要：AIM:To understand how interactions between hepatitis C virus(HCV) and the host's immune system might lead to viral persistence or effective elimination of HCV.METHODS:Nucleotides 3519-3935 of the non-structural 3(NS3) region were amplified by using reverse transcription polymerase chain reaction(PCR).PCR products of the HCV NS3 regions were integrated into a PCR T7TOPO TA vector and then sequenced in both directions using an automated DNA sequencer.Relative major histocompatibility complex binding levels of wild-type and variant peptides were performed by fluorescence polarization-based peptide competition assays.Peptides with wild type and variant sequences of NS3 were synthesized locally using F-moc chemistry and purified by high-performance liquid chromatography.Specific cytotoxic T lymphocytes(CTLs) clones toward HCV NS3 wild-type peptides were generated through limiting dilution cloning.The CTL clones specifically recognizing HCV NS3 wild-type peptides were tested by tetramer staining and flow cytometry.Cytolytic activity of CTL clones was measured using target cells labeled with the fluorescence enhancing ligand,DELFIA EuTDA.RESULTS:The pattern of natural variants within three human leukocyte antigen(HLA)-A2-restricted NS3 epitopes has been examined in one patient with chronic HCV infection at 12,28 and 63 mo post-infection.Results obtained may provide convincing evidence of immune selection pressure for all epitopes investigated.Statistical analysis of the extensive sequence variation found within these NS3 epitopes favors a Darwinian selection model of variant viruses.Mutations within the epitopes coincided with the decline of CTL responses,and peptide-binding studies suggested a signif icant impact of the mutation on T cell recognition rather than peptide presentation by HLA molecules.While most variants were either not recognized or elicited low responses,such could antagonize CTL responses to target cells pulsed with wild-type peptides.CONCLUSION:Cross-recognition of CTL epitopes from wild-type aAIM:To understand how interactions between hepatitis C virus(HCV) and the host s immune system might lead to viral persistence or effective elimination of HCV.METHODS:Nucleotides 3519-3935 of the non-structural 3(NS3) region were amplified by using reverse transcription polymerase chain reaction(PCR).PCR products of the HCV NS3 regions were integrated into a PCR T7TOPO TA vector and then sequenced in both directions using an automated DNA sequencer.Relative major histocompatibility complex binding levels ...

关 键 词：EPITOPES Human T Cells CYTOTOXIC ANERGY VIRAL 

分 类 号：R392[医药卫生—免疫学]