Epitopes described in "Hepatitis C virus (HCV)-specific immune responses of long-term injection drug users frequently exposed to HCV."

Article Authors:Eishiro Mizukoshi; Christoph Eisenbach; Brian R Edlin; Kimberly P Newton; Sukanya Raghuraman; Christina Weiler-Normann; Leslie H Tobler; Michael P Busch; Mary Carrington; Jane A McKeating; Thomas R O'Brien; Barbara Rehermann
Article Title:Hepatitis C virus (HCV)-specific immune responses of long-term injection drug users frequently exposed to HCV.
Reference Detail
Reference ID:1013647
Abstract:BACKGROUND: Injection drug users (IDUs) who successfully clear hepatitis C virus (HCV) have a reduced risk of developing chronic reinfection, despite their continuing exposure to the virus. To identify immunological correlates for this apparent protection, we studied HCV-specific immune responses in long-term IDUs (duration, >10 years). METHODS: HCV-specific T cell responses were assessed in proliferation, enzyme-linked immunospot (ELISPOT), interferon (IFN)-gamma secretion, and cytotoxicity assays, whereas HCV-specific antibodies were assessed in enzyme immunoassays (EIAs), chemiluminescent assays, and in vitro neutralization assays. RESULTS: HCV-specific T cell proliferation and IFN-gamma production were more common in nonviremic EIA-positive IDUs (16 [94%] of 17 IDUs) than in viremic EIA-positive IDUs (9 [45%] of 20 IDUs) (P= .003). They were also noted in 16 (62%) of 26 nonviremic EIA-negative IDUs. In contrast, 19 (90%) of 21 viremic IDUs displayed neutralizing antibodies (nAbs), compared with 9 (56%) of 16 nonviremic EIA-positive IDUs (P= .04) and 0 of 24 nonviremic EIA-negative IDUs. Nonviremic IDUs with nAbs were older (P= .0115) than those without nAbs, but these groups did not differ in terms of either injection drug use duration or HCV-specific T cell responses. CONCLUSION: The reduced risk of HCV persistence in IDUs previously recovered from HCV infection correlated with T cell responses, and prolonged antigenic stimulation appears to be required to maintain humoral responses.
Affiliations:Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda 20892, USA.
Reference Type:Literature
PubMed ID:18505381
Journal:J Infect Dis
Journal Volume:198
Article Pages:203-12
Journal ISSN:0022-1899
Article Chemical List:Cytokines;Viral Proteins;Interferon-gamma
Article MeSH List:Cross-Sectional Studies; Cytokines(secretion); Genotype; Hepacivirus(genetics; pathogenicity); Hepatitis C(epidemiology; immunology; transmission); Humans; Incidence; Interferon-gamma(blood); Leukocytes, Mononuclear(immunology; virology); Lymphocyte Activation; Reverse Transcriptase Polymerase Chain Reaction; Risk Assessment; Substance Abuse, Intravenous(immunology); T-Lymphocytes(immunology); United States(epidemiology); Viral Proteins(genetics); Viremia(epidemiology)
Curation Last Updated:2015-06-05 01:28:01