Diversity of immune checkpoints in cancer immunotherapy

Abstract

Finding effective treatments for cancer remains a challenge. Recent studies have found that the mechanisms of tumor evasion are becoming increasingly diverse, including abnormal expression of immune checkpoint molecules on different immune cells, in particular T cells, natural killer cells, macrophages and others. In this review, we discuss the checkpoint molecules with enhanced expression on these lymphocytes and their consequences on immune effector functions. Dissecting the diverse roles of immune checkpoints in different immune cells is crucial for a full understanding of immunotherapy using checkpoint inhibitors.

Keywords: NK cell; T cell; immune checkpoint; immunotherapy; macrophage.

Figure 1

Different immune checkpoint molecules expressed on different immune cells. (A) Different immune checkpoint molecules expressed on T cell and the corresponding ligand molecules expressed on tumor cells. (B) Different immune checkpoint molecules expressed on NK cell and the corresponding ligand molecules expressed on tumor cells. (C) Different immune checkpoint molecules expressed on Macrophage and the corresponding ligand molecules expressed on tumor cells. (D) Different immune checkpoint molecules expressed on dendritic cell and the corresponding ligand molecules expressed on tumor cells.

Figure 2

Different ICs expressing on different lymphocytes and and the targeted blocking antibody.