Magnitude of EBV-specific CD8+ T cell responses in HD and MS patients.

The frequencies of CD8+ T cells specific for EBV latent and lytic antigens were assessed in HD (n = 17) and total untreated MS patients (n = 26) (A), as well as in untreated active MS (a-MS, n = 13) and inactive MS (i-MS, n = 13) patients, IFN-β-treated active MS patients (a-MS IFN-β, n = 4) and natalizumab (NTZ)-treated inactive MS patients (i-MS NTZ, n = 14) (B, C). The percentages of antigen-specific CD8+ T cells within the CD3+ CD8+ T cell population were analyzed by staining with the corresponding HLA-A*0201 and HLA-B*0801 pentamers. Symbols in B and C refer to individual responses to peptide epitopes from the indicated EBV latent and lytic proteins from each donor. The frequencies were calculated after gating on total, live CD3+ CD8+ T cells. Data are shown in logarithmic scale. In A the bars represent the median ± the minimum and maximum value while in B and C the bars represent mean values ± SD; p values are calculated with unpaired t-test with 95% confidence intervals. (D) Representative flow cytometric expression profiles for pentamer+ CD8+ T cells specific for the indicated EBV latent and lytic antigens in HD, untreated inactive MS and active MS patients are shown in D. Numbers represent percentages of pentamer+ cells within the CD3+ CD8+ T-cell population.