Current status and perspectives of immune-based therapies for hepatocellular carcinoma

Figure 1 Immune-based therapies for hepatocellular carcinoma. Tumor-specific T cells can be stimulated by several ways including adoptive cell therapy, tumor vaccines, cytokines or by inhibiting immune suppressive mechanisms (immune checkpoint inhibitors, depletion of Tregs or MDSCs). These tumor-specific T cells are able to kill the tumor cells in an antigen-specific way. Conventional therapies (RFA, TACE, PEI, microwave ablation, TARE) can destroy tumor cells, which result in the release of tumor antigens and danger-associated molecular patterns that can activate DCs resulting in the activation of tumor-specific T cells. RFA: Radiofrequency ablation; PEI: Percutaneous ethanol injection; TACE: Transarterial chemoembolization; TARE: Transarterial radioembolization; DAMPs: Danger-associated molecular patterns; PAMPs: Pathogen-associated molecular patterns; DC: Dendritic cell; NK: Natural killer; LAK: Lymphokine-activated killer; NKT cell: Natural killer T cell; CIK: Cytokine-induced killer; CAR: Chimeric antigen receptor; CTL: Cytotoxic T lymphocyte; Treg: Regulatory T cell; MDSC: Myeloid derived suppressor cells; CTLA-4: Cytotoxic T lymphocyte antigen 4; PD-1: Programmed-death 1.