Fig. 2

PD-1/PD-L1 interface and binding mechanism of PD-1 inhibiting monoclonal antibodies (mAbs). A Illustration of the PD-1/PD-L1 interaction interface. B Superimposition of PD-1 binding mAbs on a single PD-1 molecule, with corresponding PDB IDs listed in Table 1. C Alignment of the complementarity-determining regions (CDRs) from the mAbs presented in panel B. D Superimposition of PD-1 binding mAbs on a single PD-1 molecule, constructed using AlphaFold 3. E Alignment of the CDRs from the mAbs depicted in panel D. F Identification of two non-overlapping epitopes for retifanlimab, one of which overlaps with nivolumab (panel B), along with new glycosylation sites at N74 and N116