LPS-activated DCs also improve PD-1 therapy.

(A) Experimental outline for evaluating whether LPS-activated DCs can improve the efficacy of PD-L1 blockade therapy. Mice chronically infected with LCMV Cl-13 received a PD-L1 blockade regimen combined with specific transfer of LPS-activated DCs. (B) Summary of virus-specific CD8 T cells in spleen. (C) Summary of viral control in spleen. (D) Experimental outline for evaluating the role of TLR4 signaling in potentiating the efficacy of PD-L1 blockade therapy after LPS treatment. Mice chronically infected with LCMV Cl-13 received PD-L1 blockade with LPS-activated DCs that lacked TLR4 (Tlr4-/-). (E) Summary of virus-specific CD8 T cells in spleen. (F) Summary of viral control in spleen. For spleen plaque assays, the limit of detection is indicated by a dashed line. Data are from one representative experiment. Experiments were performed 2 times with similar results, n = 4–6 mice per experiment; data from one experiment are shown. ns, not significant. Indicated p-values were calculated using Mann-Whitney tests. Error bars represent SEM.