Figure 3.

Mouse PD-L1 interacts with the human PD-1

(A) The superposition of ¹H-¹⁵N HMQC spectra of the hPD-1 (blue) and its complex with PD-L1 (red) of either the mouse (mPD-L1, left panel) or human (hPD-L1, right panel) origin. In both 2D spectra, PD-1/PD-L1 complex formation is evidenced by the broadening of resonance signals caused by increased transverse relaxation.

(B) The interaction of hPD-1 with either mPD-L1 (left) or hPD-L1 (right) was tested with MicroScale Thermophoresis (MST) binding assay. The resulting K_D value for hPD-1/hPD-L1 was 11.9 ± 2.8 μM, and 3.2 ± 0.2 μM for hPD-1/mPD-L1. All MST measurements were performed in two independent dilution series. Errors for measurement points are reported as standard deviations.