Background: The cellular immune response is important in chronic hepatitis C (CHC). To better understand its mechanism, we examined dendritic cells (DCs) and hepatitis C virus (HCV)-specific cytotoxic T cells (CTLs), which are thought to contribute to liver injury and viral clearance.
Methods: CHC patients received 24 weeks of interferon-alpha-based antiviral therapy. We analyzed time-sequential frequencies of peripheral DCs, classified as myeloid DCs (mDCs) or plasmacytoid DCs (pDCs), together with peptide major histocompatibility class I tetramers, epitope specific for HCV core 129-137 (t*24/c129) or HCV NS3 1296-1304 (t*24/ns1294), directly ex vivo.
Results: The mDC and pDC populations changed in parallel (P < 0.05), showing a significant transient decrease at weeks 12 and 16 during the therapy, and then recovering. However, neither of the tetramer results showed a direct correlation with the kinetics of peripheral DCs.
Conclusions: There is an apparent effect of antiviral therapy or a subsequent reduction of HCV on host immunity, but the effect may not include the induction of CTLs in CHC.