Figure 3.

Mechanism of anti-programmed death 1 (PD-1) receptor and anti-programmed death ligand 1 (PD-L1)/L2 inhibitors mediated cancer immunotherapy. Antigen-presenting cells (APCs) bind to antigen (Ag) that released from tumor cells and T cells to activate T-cell receptor (TCR) and MHC binding. PD-L1 of tumor stroma interacts with PD-1 of T cells to suppress the T-cell mediated tumor cytotoxicity. Tumor associated macrophage (TAM), myeloid derived suppressor cells (MDSC) has crucial role in PD-1/PD-L1 mediated tumor immunosuppression (Ohaegbulam et al., 2015).