FIGURE 4.

αPD-1 rescues the reduced Ca²⁺ influx induced by PDL-1-Fc in HDs. (A) Representative traces of intracellular Ca²⁺ response in activated CD8⁺ PBTs of HDs. Cells were loaded with Fura-2 and Ca²⁺ fluxes were elicited by TG/0 mM Ca²⁺ followed by 0.5 mM Ca²⁺ (See Material and Methods). Cells were incubated with plate bound PD-L1 (PD-L1-Fc, 10 μg/ml for 72 h) followed by treatment with αPD-1 (10 μg/ml for 6 h). (B) Summary of ∆Ca²⁺ values of activated CD8⁺ PBTs of HDs (n = 160–255 cells from nine HDs, 20–50 cells were recorded from a single HD, see Methods). The values in panel B are represented as box and whisker plots. The lower and upper bound of the box represent 25^th and 75^th percentiles respectively. Median values are shown as horizontal line. The lower and upper error bars represents 10^th and 90^th percentile respectively. Data were analyzed using ANOVA (p < 0.001) on ranks followed by Dunn’s post hoc analysis.