Figure 3.

Enhancement of cell therapy by PD-1 blockade was independent of transferred T cell Pdcd1 expression and was dependent on endogenous T cells. (A) Tumor curves showing treatment of C57BL/6J mice bearing established B16-K-OVA tumors with adoptive transfer of Pdcd1-KO OT-I T cells, with or without PD-1 blockade. Mice received host conditioning followed by the therapy indicated in the symbol legend. ‘OT-I.PD1KO’ indicates administration of Pdcd1-KO OT-I T cells. ‘Anti-PD-1’ indicates administration of anti-PD-1 antibody. Statistical significance was determined with a mixed model two-way analysis of variance with repeated measures. * represents p<0.05, *** represents p<0.001. Two independent experiments shown. (B) Tumor curves showing treatment of host mice with absent or restricted endogenous T-cell repertoires with wild-type OT-I T cells, with or without PD-1 blockade. The knockout gene or transgene for the host mice in each experiment is indicated above each tumor graph. The symbol legend shows the treatment that was given. ‘OT-I’ indicates OT-I T cell administration. ‘Anti-PD-1’ indicates anti-PD-1 antibody administration. The data shown have five mice per group and are representative of two independent experiments. Data are represented as mean±SEM. PD-1, programmed cell death protein-1.