title: Modulation of the peripheral T-Cell response by CD4 mutants of hepatitis C virus: transition from a Th1 to a Th2 response.
abstract: A disturbing feature of hepatitis C virus (HCV) is its long-term persistence in roughly 85% of those infected. Escape mutants may play a major role in HCV persistence. Our previous studies have identified a human leukocyte antigen DRB1*15 (HLA-DRB1*15) restricted Th1 epitope in the HCV NS3 protein, NS3(358-375), and escape variants of this epitope that may emerge under immune selection. Such variants attenuate or fail to stimulate T-cell proliferation. Here we provide data from peripheral blood mononuclear cells derived from four HLA-DRB1*15 patients chronically infected with HCV, and report that naturally occurring single amino acid substitutions in the Th1 epitope NS3(358-375) fail to stimulate proliferation, which is accompanied by a shift in cytokine secretion patterns from one characteristic of a Th1 antiviral responses to a Th2 form. Further, in one patient, we demonstrate that HCV variant peptides can effectively inhibit host polyclonal peripheral T-cell proliferation. We speculate that this phenomenon may be a factor in chronic HCV infection.
authors.affiliation: Section of Liver Diseases, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Jane H
authors.initials: JH
authors.lastname: Wang
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Layden
authors.forename: David D
authors.initials: DD
authors.lastname: Eckels
mesh_terms: D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D059811:HLA-DRB1 Chains; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D018936:Hepatitis C Antigens / Q000235:genetics / Q000276:immunology*; D019698:Hepatitis C, Chronic / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D009154:Mutation; D016133:Polymerase Chain Reaction; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology*; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D016207:Cytokines; D018984:Epitopes, T-Lymphocyte; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D018936:Hepatitis C Antigens; D000949:Histocompatibility Antigens Class II; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases