Figure 8. CTLA‐4 Ig (Abatacept) modulates anti‐PD‐L1 antibody binding but fails to confer PD‐1 Ig detection.

• A
  Concatenated flow cytometry plots for Abatacept‐APC binding to DG‐75 cells expressing CD80 or PD‐L1/CD80.
• B
  Titration of Abatacept staining (left hand panel) and EC50 values of Abatacept (right hand panel) for CD80 only or PD‐L1/CD80 co‐expressing DG‐75.
• C
  Concatenated plot of a one in five serial dilution of Abatacept (starting at 10 μg/ml) followed by PD‐L1 detection using antibody (MIH3 or 29E.2A3 clone) or using PD‐1 Ig, all at 1 μg/ml. DG‐75 with no ligand or PD‐L1 alone (far right) are shown as staining controls in the presence of 10 μg/ml of abatacept.
• D
  Comparison of PD‐L1 detection using PD‐1‐Ig or anti‐PD‐L1 antibodies (MIH3 or 29E.2A3 clone) with and without prior incubation with 10 μg/ml of abatacept, based on data from (C).
• E
  Graphs showing PD‐L1 detection under conditions used in (C) following different Abatacept incubation periods (30 min, 3 h or 6 h).

Data information: Data are representative of three independent experiments showing mean ± SEM. *P ≤ 0.05, **P ≤ 0.01, ns, not significant: paired t‐test (B) or RM one‐way ANOVA (D).