Figure 1.
Structural basis of PD-1/PD-L1 checkpoint blockade by antibodies and small molecules. (A) Structure of the PD-1 and PD-L1 complex (modified from PDB ID 3BIK). (B) Overall structure of the hPD-L1 and avelumab-Fab complex, the hPD-L1 and atezolizumab-Fab complex, the hPD-L1 and durvalumab-Fab complex, the hPD-L1 and BMS-936559-Fab complex, and the hPD-L1 and KN035 nanobody complex (magenta ribbon model) (modified from PDB IDs 5GRJ, 5X8L, 5X8M, 5GG7, and 5JDS, respectively). The heavy chain (VH) and the light chain (VL) of the antibody-Fab fragments are represented by red and yellow ribbon models, respectively. (C) Overall structure of the hPD-1 and nivolumab-Fab complex and the hPD-1 and pembrolizumab-Fab complex (modified from PDB IDs 5GGR and 5GGS, respectively). (D) Crystal structure of BMS-202 (non-peptide small molecule inhibitor, blue stick model) on the surface of hPD-L1 (light yellow ribbon structure) (modified from PDB ID 5J89). (E) Structure of macrocyclic peptide inhibitor “22” in complex with hPD-L1 (light yellow ribbon model = hPD-L1; blue ball and stick model = peptide) (modified from PDB ID 5O45).