Tumor-infiltrating T-Lymphocyte immunity-related immune tolerance and anti–programmed cell death protein 1/ligand of programmed cell death protein 1 therapy for advanced hepatocellular carcinoma

Abstract

Abstract Systemic therapy has become the standard treatment for patients with advanced hepatocellular carcinoma (HCC) whose treatment options are limited. However, the long-term patient response to drugs and the survival outcomes remain a concern. With increasing exploration of the HCC microenvironment, particularly in terms of T lymphocyte immunity, a new era of immunomolecular targeted therapy, based on molecular signaling, has arrived for advanced HCC. In the study of immune tolerance of the intrinsic HCC microenvironment, we found that multiple immunosuppressive mechanisms and immune checkpoint inhibitors, such as anti–programmed cell death protein 1/ligand of programmed cell death protein 1 therapy, have improved clinical outcomes in some patients with advanced HCC. Furthermore, various combination therapies have been investigated, and HCC types have been categorized into different types based on anti–programmed cell death protein 1 (PD-1)/ligand of programmed cell death protein 1 (PD-L1) treatment. In this paper, we first discuss the tumor-infiltrating T lymphocyte immunity and immune tolerance of HCC. We then clarify the basic mechanism of anti–PD-1/PD-L1 therapy and discuss the types of HCC based on anti–PD-1/PD-L1 therapy. Thereafter, we explain the relevant studies and mechanisms of combination therapy of anti–PD-1/PD-L1 with antiangiogenesis drugs or multikinase kinase inhibitors, anti–T lymphocyte–related signaling pathways in HCC, and other anti-CD8+ T cell immune checkpoints. In this way, this review offers a deeper understanding of anti–PD-1/PD-L1 immunotherapy for advanced HCC, in order to provide better individualized treatments for patients with advanced HCC.