Fig. 2

SMC18 binds SIRPα and PD-L1 to block CD47/SIRPα and PD-1/PD-L1 interaction. A, B The affinity of SMC18 with SIRPα and PDL1 proteins was assessed using MST. Dose curves were generated and presented. C, D Flow cytometry was employed to evaluate the ability of the SMC18 small molecule to block CD47/SIRPα and PD-1/PD-L1 interactions. The fluorescence intensity of CD47/PD-L1-Fc protein binding to cells with stable expression of SIRPα/PD-1 was measured at different concentrations of the small molecule, and concentration curves were constructed. E, F Interactions between SMC18 (orange-red) and amino acids derived from human SIRPα E and PD-L1 F were displayed. The specific amino acid residues involved in the CD47/SIRPα (blue-gray) and PD-1/PD-L1 (cyan-blue) interactions were indicated