Fig 2.

Epitope-specific CD8⁺ T cell responses in mice infected with WT and variant viruses. (A) On the indicated days postinfection, SJL mice (3 mice per group) infected with WT or variant viruses were sacrificed, and isolated CNS-infiltrating MNCs were stimulated with PBS or VP3_159-166, VP3_173-181, or VP1_11-20 peptide for 6 h. The proportion of CNS CD8⁺ T cells was analyzed using flow cytometry after staining with H-2K^s–VP3_159-166 and H-2K^s–VP3_173-181 tetramers. (B) The proportion of epitope-specific tetramer-positive CD8⁺ T cells (top) and the number of epitope-specific tetramer-positive CD8⁺ T cells in the CNS (bottom) are shown. *, P < 0.05; **, P < 0.01. (C) The percentage of IFN-γ-producing CD8⁺ T cells of the total CD8⁺ T cells is shown in the upper right quadrant of each plot. Cells were stained for both CD8 and intracellular IFN-γ for flow cytometric analysis. A representative fluorescence-activated cell sorter analysis plot of three independent experiments is shown. (D) The proportion (top) and number (bottom) of epitope-specific IFN-γ-producing CD8⁺ T cells in the CNS of SJL mice during viral infection are shown. The values given are the means of the percentages or numbers of IFN-γ-producing CD8⁺ T cells from four independent experiments (mean ± SD).