Figure 6. ADI-PEG 20 blocks anti-CD3/CD28 induced upregulation of PD-1, CTLA-4 and PD-L1 on T cells.

PBMCs were stimulated with anti-CD3/CD28 Dynabeads in the presence or absence of ADI-PEG 20 or mutant ADI-PEG 20. Percentages of PD-1+ (A–B), CTLA-4+ (C–D) and PD-L1+ (E–F) cells in CD4+ T cells (A, C, E) and CD8+ T cells (B, D, F) were determined by flow cytometry at 24 h, 48 h & 72 h.