Viral epitope-specific T cell responses induced in chronic, hepatitis C virus-infected patients

Background: Approximate 180 million people worldwide are infected with hepatitis C virus (HCV). Historically, vaccination has been the most effective strategy for controlling infections of such major health concern. Therapeutic vaccine strategies for HCV, however, have demonstrated negligible success. Aim: Demonstrate the ability of highly-conserved viral epitopes to overcome the immune dysfunction often associated with chronic HCV infections. Methods: T cells from five chronic, HCV-infected patients were immunophenotyped by flow cytometry. The ex vivo T cell responses to highly-conserved viral epitopes were assessed by ELISpot assay and cytokine bead array analysis. Results: Both HLA-DRB-1-and HLA-A2-restricted viral epitopes induced specific, TH1-type cytokine production by T cells derived from the patients. Induction occurred despite expression of cell-surface inhibitory molecules and the presence of regulatory T cells. Conclusion: These findings support the potential ability of a broad, multi-epitope-based therapeutic vaccine to elicit virus-specific immune responses in chronic hepatitis C virus-infected patients. (C) 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.