Primary T-cell response in HP mice. (A) Splenocytes were harvested, and CD8 or CD4 numbers (means ± SD) were counted from HP or WT naive mice. (B) Splenocytes were harvested, and CD8 or CD4 numbers were counted from LCMV-infected HP (n = 7) or WT naive mice (n = 5) at day 8. (C) Splenocytes were harvested and stimulated with LCMV-specific peptides for 5 hours. Dot plots show CD44⁺IFNγ⁺LCMV-specific CD8 T cells from a representative uninfected HP mouse, infected HP mouse, or infected WT mouse. Numbers refer to percentage of cells in designated quadrants. (D) Splenocytes from LCMV-infected mice were harvested and stimulated with LCMV-specific peptides for 5 hours. After stimulation the numbers of CD8⁺CD44⁺IFNγ⁺ (left; means ± SD) or CD4⁺CD44⁺IFNγ⁺ (right; means ± SD) cells recognizing each peptide were counted. This is a representative result from 3 repeated experiments with 2 to 7 mice per group. P value was analyzed by t test.