FIG. 2.

Temporal relationship between CD4⁺ CD25⁺ frequency and HBV-specific CD8⁺-T-cell response. Direct ex vivo frequencies of circulating CD4⁺ CD25⁺ cells were calculated at the indicated time points in the two HLA-A2⁺ patients indicated. In parallel, HBV-specific CD8⁺-T-cell responses were calculated by stimulating PBMC with 10 HBV peptides representing known HLA-A2-restricted epitopes. The frequency of HBV-specific CD8⁺ cells was calculated with ICS after 8 days of in vitro stimulation. Frequencies of IFN-γ-producing CD8⁺ cells are indicated only for responding peptides. Patients were on lamivudine therapy; HBV DNA level was <10⁵ copies/ml at all time points.