Figure 5. Inhibiting De Novo DNA Methylation Synergizes with PD-L1 Blockade.

(A) Experimental setup of anti-PD-L1 treatment in chronically infected WT and Dnmt3a cKO mice.

(B) Representative FACS analysis and summary graphs of gp33-, gp276-, and np396-specific CD8 T cell frequencies in the spleens of treated and untreated chronically infected WT and cKO mice; WT mock-treated = gray bars, WT anti–PD-L1–treated = red bars, cKO mock-treated = black bars, and cKO PD-1 blockade–treated = green bars.

(C) Representative FACS analysis showing the frequencies of gp33-specific CD8 T cells in the lungs and (D) liver of chronically infected WT and cKO mice after mock or PD-1 blockade treatment.

(E) Longitudinal analysis of the gp33-specific TCR repertoire Simpson’s diversity index among WT and cKO CD8 T cells isolated from the peripheral blood before and after PD-1 blockade treatment.

(F) Representative intracellular FACS analysis of IFNγ and IL-2 expression from gp33-stimulated CD44^hi CD8 T cell splenocytes of mock or PD-1 blockade-treated chronically infected WT and cKO mice. Summary graphs of fold change in quantity of total IFNγ-expressing or IFNγ and IL-2 co-expressing CD8 T cells from spleens of mock or PD-1 blockade–treated chronically infected WT and cKO mice.

(G) Longitudinal measurement of viral titers in the serum and summary graphs of the viral titers in the spleen or liver of chronically infected WT and cKO mice after mock or PD-1 blockade treatment.

Fold change was calculated relative to mock-treated WT mice. N= 3–5 mice per group of two independent experiments. Error bars indicate SEM.