Figure 7.

Lack of PD-1 signaling results in impaired viral control. WT or PD-L1^−/− mice were re-infected i.c. with MuPyV or mock inoculated at 35 dpi, then euthanized 5 days later. Total CD8 T cells and D^bLT359⁺ CD8 T cells from brains were analyzed by flow cytometry. (A) Number of total CD8 and D^bLT359⁺ CD8 T cells per brain, (B) Brain viral DNA genome copies by qPCR at 5 days after re-infection. (C) Number of IFN-γ⁺ (left panel) and IFN-γ⁺ CD107a/b⁺ (right panel) CD8 T cells upon in vitro stimulation with LT359 peptide. (D) Frequency of Ki67⁺ LT359⁺ CD103^+/− CD8 T cells upon reinfection. Data from two independent experiments with 3–5 mice per group. Two-way ANOVA with Tukey multiple comparison test was performed. Values represent mean ± SD; *p ≤ 0.05, **p ≤ 0.01. (D) Frequency of Ki67⁺ LT359⁺ CD103^+/− CD8 T cells upon reinfection.