Figure 5.

(A) Both THP-1 cells and THP-1 derived macrophages expressed PD-1 and CD68. T24 cells expressed PD-L1. (B) A co-IP assay showing the binding between CD68 and PD-1, hinting at the possibility of a CD68 and PD-1 interaction. (C) The binding of CD68 and PD-1 promoted THP-1 derived macrophages to M2 polarization whereas the blockage can reverse the process. (D) Molecular docking showing the interactions of CD68 and PD-1 through possible LAMP-like and IgV domains. SP indicates signal peptide and TM indicates transmembrane domain. (E) The cell viability assays of T24, THP-1 derived macrophages and PBMC co-culture experiments. T24 cell group and THP-1 derived macrophage group were the control groups. ***p < 0.001 (Student’s t-test).