Figure 2.

(a, b) Antibody blockade of PD-1 inhibits splenic T cell apoptosis. Immediately following intramedullary nailing of hip fractures (Fx+Sur) or sham surgery (sham), mice were randomly assigned to receive anti-PD-1 antibody (anti-PD-1), isotype control antibody (Iso), or saline. Splenocytes were harvested 24 h after surgery. Apoptosis was quantified by active caspase 3 or TUNEL assays (n = 8 per group). Results are expressed as the mean ± SD. Analysis was performed using one-way ANOVA with the Tukey post hoc test. ^∗P < 0.001 when compared to the sham group and ^∗∗P < 0.001 when compared to the Fx+Sur+anti-PD-1 group.