title: Cross-reactivity between hepatitis C virus and Influenza A virus determinant-specific cytotoxic T cells.
abstract: The cellular immune response contributes to viral clearance as well as to liver injury in acute and chronic hepatitis C virus (HCV) infection. An immunodominant determinant frequently recognized by liver-infiltrating and circulating CD8(+) T cells of HCV-infected patients is the HCV(NS3-1073) peptide CVNGVCWTV. Using a sensitive in vitro technique with HCV peptides and multiple cytokines, we were able to expand cytotoxic T cells specific for this determinant not only from the blood of 11 of 20 HCV-infected patients (55%) but also from the blood of 9 of 15 HCV-negative blood donors (60%), while a second HCV NS3 determinant was recognized only by HCV-infected patients and not by seronegative controls. The T-cell response of these healthy blood donors was mediated by memory T cells, which cross-reacted with a novel T-cell determinant of the A/PR/8/34 influenza A virus (IV) that is endogenously processed from the neuraminidase (NA) protein. Both the HCV NS3 and the IV NA peptide displayed a high degree of sequence homology, bound to the HLA-A2 molecule with high affinity, and were recognized by cytotoxic T lymphocytes with similar affinity (10(-8) M). Using the HLA-A2-transgenic mouse model, we then demonstrated directly that HCV-specific T cells could be induced in vivo by IV infection. Splenocytes harvested from IV-infected mice at the peak of the primary response (day 7 effector cells) or following complete recovery (day 21 memory cells) recognized the HCV NS3 peptide, lysed peptide-pulsed target cells, and produced gamma interferon. These results exemplify that host responses to an infectious agent are influenced by cross-reactive memory cells induced by past exposure to heterologous viruses, which could have important consequences for vaccine development.
authors.affiliation: Liver Diseases Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20982, USA.
authors.forename: H
authors.initials: H
authors.lastname: Wedemeyer
authors.forename: E
authors.initials: E
authors.lastname: Mizukoshi
authors.forename: A R
authors.initials: AR
authors.lastname: Davis
authors.forename: J R
authors.initials: JR
authors.lastname: Bennink
authors.forename: B
authors.initials: B
authors.lastname: Rehermann
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D015789:HLA-A2 Antigen / Q000235:genetics / Q000276:immunology; D016174:Hepacivirus / Q000276:immunology* / Q000502:physiology; D019698:Hepatitis C, Chronic / Q000276:immunology; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology; D066298:In Vitro Techniques; D009980:Influenza A virus / Q000276:immunology* / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D017361:Viral Nonstructural Proteins / Q000737:chemistry; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D015789:HLA-A2 Antigen; D016056:Immunodominant Epitopes; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases