title: Recovery of functional cytotoxic T lymphocytes during lamivudine therapy by acquiring multi-specificity.
abstract: To characterize cytotoxic T lymphocytes (CTLs) that appeared in circulation during lamivudine therapy, we analyzed HBV-specific CTLs using HLA-A24 tetramer and HBcAg-specific Th1 cells in patients receiving lamivudine therapy. Six patients (HLA-A24(+)) with chronic hepatitis B, six patients (HLA-A24(-)) with chronic hepatitis B, and six patients (HLA-A24(+)) with chronic hepatitis C were studied. In addition to known CTL epitopes (C117 and P756), three epitopes were confirmed as CTL epitopes (C23, S89, S226) by chromium release assay and by staining intracellular perforin. CTLs specific for P756 were most frequently found at pre-treatment. During lamivudine therapy, increase in the frequencies of HLA-tetramer(+) cells was found for C117, S89, and S226. Recovery of CTLs was observed earlier in patients with HBeAg(-)/anti-HBe(+) compared with those with HBeAg(+)/anti-HBe(-). HBcAg-specific Th1 cells did not increase significantly up to 8 weeks. T cell lines from patients with chronic hepatitis B had a lower level of proliferation (0- to 24.9-fold expansion by in vitro stimulation) and a higher ability to produce interferon-gamma (0-84% except for S89), while perforin-positive cells showed low frequencies (0-50% except for S89). In conclusion, these results suggest that lamivudine therapy induces mainly CTLs that were less frequent before the therapy. Since recovered CTLs maintained the ability to produce interferon-gamma in response to peptides, these CTLs apparently contribute to the efficacy of lamivudine therapy in patients with hepatitis B.
authors.affiliation: Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan.
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Kondo
authors.forename: Shinichi
authors.initials: S
authors.lastname: Asabe
authors.forename: Koju
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Shiina
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Niitsuma
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ueno
authors.forename: Tomoo
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use*; D000939:Epitopes; D005260:Female; D015234:HLA-A Antigens / Q000378:metabolism; D059871:HLA-A24 Antigen; D006512:Hepatitis B Core Antigens / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000276:immunology* / Q000821:virology; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis; D019259:Lamivudine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects* / Q000276:immunology*; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology
chemical_list: D000998:Antiviral Agents; D000939:Epitopes; D015234:HLA-A Antigens; D059871:HLA-A24 Antigen; D006512:Hepatitis B Core Antigens; D019259:Lamivudine; D007371:Interferon-gamma