Extended Data Fig. 7. Importance of PD-1/PD-L1 blockade at the target site in reducing viral load during chronic LCMV infection.

a, Experimental design. Mice chronically infected with LCMV were divided into two groups; one group was treated with IL-2 only for 13 days (IL-2 group), and the second group was given IL-2 for 10 days followed by 2 doses of anti-PD-L1 antibody on days 10 and 12 (IL-2 + late anti-PD-L1 group). Mice were then analyzed at day 14 for LCMV-specific CD8⁺ T-cell responses, viral titre, and liver immunopathlogy. b, Numbers of LCMV-specific (D^bGP33⁺ and D^bGP276⁺) CD8⁺ T cells. c, Viral titre in the indicated tissues. d-f, Immunopathological assessment. Serum levels of alanine aminotransferase (ALT) (d), liver pathology score (e), and number of TUNEL⁺ sinusoidal cells and hepatocytes (f). Results were pooled from 2–4 experiments with n = 2–5 per group in each experiment (b–f). For serum ALT levels, serum samples were pooled from 2–3 mice. TUNEL staining was done on one of the representative experiments with n = 4 per group. Data are presented as geometric mean and 95% CI (b) or mean and SD (c-f) with p values. Statistical comparisons were performed using two-tailed unpaired Mann-Whitney test (b), or two-tailed unpaired t-test (c–f). ALT, alanine aminotransferase. TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling.