Antibodies, Monoclonal ; chemistry ; metabolism ; therapeutic use ; B7-H1 Antigen ; chemistry ; metabolism ; Humans ; Kinetics ; Models, Molecular ; Protein Binding

Antibody-based PD-1/PD-L1 blockade therapies have taken center stage in immunotherapies for cancer, with multiple clinical successes. PD-1 signaling plays pivotal roles in tumor-driven T-cell dysfunction. In contrast to prior approaches to generate or boost tumor-specific T-cell responses, antibody-based PD-1/PD-L1 blockade targets tumor-induced T-cell defects and restores pre-existing T-cell function to modulate antitumor immunity. In this review, the fundamental knowledge on the expression regulations and inhibitory functions of PD-1 and the present understanding of antibody-based PD-1/PD-L1 blockade therapies are briefly summarized. We then focus on the recent breakthrough work concerning the structural basis of the PD-1/PD-Ls interaction and how therapeutic antibodies, pembrolizumab targeting PD-1 and avelumab targeting PD-L1, compete with the binding of PD-1/PD-L1 to interrupt the PD-1/PD-L1 interaction. We believe that this structural information will benefit the design and improvement of therapeutic antibodies targeting PD-1 signaling.
Antibodies, Monoclonal ; immunology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; immunology ; therapeutic use ; B7-H1 Antigen ; antagonists & inhibitors ; immunology ; Humans ; Neoplasms ; drug therapy ; immunology ; pathology ; Programmed Cell Death 1 Receptor ; antagonists & inhibitors ; immunology ; Signal Transduction ; drug effects ; immunology ; T-Lymphocytes ; immunology