PMID- 20419832
OWN - NLM
STAT- MEDLINE
DCOM- 20100729
LR  - 20211020
IS  - 2219-2840 (Electronic)
IS  - 1007-9327 (Print)
IS  - 1007-9327 (Linking)
VI  - 16
IP  - 16
DP  - 2010 Apr 28
TI  - Natural epitope variants of the hepatitis C virus impair cytotoxic T lymphocyte 
      activity.
PG  - 1953-69
AB  - 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((R)) T7TOPO((R)) 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 significant 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 and 
      naturally-occurring HCV variants may lead to impaired immune responses and 
      ultimately contribute to viral persistence.
FAU - Wang, Shuping
AU  - Wang S
AD  - Department of Pathology, University of Utah, Salt Lake City, UT 84112, USA.
FAU - Buchli, Rico
AU  - Buchli R
FAU - Schiller, Jennifer
AU  - Schiller J
FAU - Gao, Jianen
AU  - Gao J
FAU - VanGundy, Rodney S
AU  - VanGundy RS
FAU - Hildebrand, William H
AU  - Hildebrand WH
FAU - Eckels, David D
AU  - Eckels DD
LA  - eng
GR  - R01 DK057732/DK/NIDDK NIH HHS/United States
GR  - NIH DK-57732/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PL  - United States
TA  - World J Gastroenterol
JT  - World journal of gastroenterology
JID - 100883448
RN  - 0 (Epitopes)
RN  - 0 (Fluorescent Dyes)
RN  - 0 (Ligands)
RN  - 0 (Peptides)
SB  - IM
MH  - Chromatography, High Pressure Liquid/methods
MH  - Cloning, Molecular
MH  - Epitopes/*chemistry
MH  - Flow Cytometry/methods
MH  - Fluorescent Dyes/chemistry
MH  - Genetic Variation
MH  - Hepacivirus/*chemistry/*immunology
MH  - Humans
MH  - Immune System
MH  - Ligands
MH  - Models, Genetic
MH  - Mutation
MH  - Peptides/chemistry
MH  - Reverse Transcriptase Polymerase Chain Reaction
MH  - T-Lymphocytes, Cytotoxic/immunology/*virology
PMC - PMC2860072
EDAT- 2010/04/27 06:00
MHDA- 2010/07/30 06:00
PMCR- 2010/04/28
CRDT- 2010/04/27 06:00
PHST- 2010/04/27 06:00 [entrez]
PHST- 2010/04/27 06:00 [pubmed]
PHST- 2010/07/30 06:00 [medline]
PHST- 2010/04/28 00:00 [pmc-release]
AID - 10.3748/wjg.v16.i16.1953 [doi]
PST - ppublish
SO  - World J Gastroenterol. 2010 Apr 28;16(16):1953-69. doi: 10.3748/wjg.v16.i16.1953.