Hepatocellular carcinoma immune microenvironment and check point inhibitors-current status

Figure 1 Immune activation in the tumor microenvironment. Interaction between tumor cells and the immune system is demonstrated in this figure. Antigen presentation by dendritic cells (antigen presenting cells) leads to activation of cytotoxic T lymphocytes which eventually leads to death of tumor cells by the release of granzymes and perforins. Activation of cytotoxic T cells require additional co-stimulatory signals during the interaction between dendritic cells and cytotoxic CD8⁺ T lymphocytes. PD-1: Programmed death receptor-1; PD-L1: Programmed death receptor ligand-1; ICI: Immune checkpoint inhibitor; TCR: T-cell receptor; MHC-1: Major histocompatibility complex I.