CD96: immunoregulation and its role and prospect in immunotherapy of primary hepatocellular carcinoma.

Abstract

Recently, immune checkpoint inhibitors have been widely used in the treatment of advanced liver cancer. Immune checkpoints are a type of molecules that play an important role in the self-regulation of the immune system. In tumor immunity, their activation by immune checkpoints leads to the inhibition of effector lymphocyte activation or the mediation of cytotoxic T cell dysfunction, resulting in immune escape. These immune checkpoints include programmed death receptor 1 (PD-1) and its ligand PD-L1, as well as cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and others. Immune checkpoint inhibitors block the interaction between immune checkpoint receptors and ligands, thereby relieving the immune suppression caused by immune checkpoints, and reactivating immune cells to exert antitumor effects. With the continuous progress of immunotherapy research, drugs targeting PDL-1, PD-1, and CTLA-4 have played an important role in clinical treatment. However, some patients still cannot benefit from immunotherapy; therefore, multitarget immunotherapy is an important way to improve the response rate of immunotherapy. CD96 is one of the members of the immunoglobulin superfamily receptors, which mainly functions by regulating natural killer cells and CD8+ T cells, and is expected to become a new generation of immune checkpoints. This article reviews the molecular structure of CD96, its role in tumor immunity, and its application in hepatocellular carcinoma, hoping to provide reference for related research.