Figure 5.

Peptides targeting immune checkpoints. There are three pairs of immune checkpoints in the interaction between APCs and T cells: 1) PD-L1 or PD-L2/PD-1, 2) LAG-3/MHC, and 3) CD28/CTLA-4. Regarding the interaction between T cells and tumor cells, five pairs of immune checkpoints associated with peptides are shown. Among them, 4) VISTA/VSIG-3, 5) TIGIT/CD155, and 6) BTLA/HVEM are new immune checkpoints. In addition, 7) CD47/SIRPα represents a pair of immune checkpoints in the interaction between macrophages and tumor cells. The plus sign (pink) indicates a positive effect on the antitumor response, while the minus sign (gray) indicates an inhibitory effect. The peptides targeting these immune checkpoints are highlighted in yellow.