Skip to main content
. 2021 Jul 21;12:4445. doi: 10.1038/s41467-021-24767-5

Fig. 6. Colocalization of CD137 and PD-L1 mediates CD137 clustering.

Fig. 6

Fold induction of CD3-stimulated Jurkat NFκB-luc-CD137 reporter activity after 24 hours of co-incubation with either a CHO-PD-L1 cells or b human tumor cells endogenously expressing PD-L1 at increasing concentrations of MCLA-145; numbers in brackets indicate PD-L1 binding sites per cell as determined by QIFIKIT analysis; c Schematic illustrating the VeraTag assay to measure CD137 clustering; d CD137-expressing activated Jurkat T cells and PD-L1-expressing CHO cells cocultured with 10 µg/mL test antibody, fixed and measured for CD137 proximity using two different CD137 detection antibodies; e Schematic illustrating the VeraTag assay to measure CD137 and PD-L1 proximity; f Cells cultured and prepared as in (d) to measure PD-L1 and CD137 in proximity, RPA relative peak area; confocal images of CD137 receptor internalization in cocultures of activated CD8+ T cells and CHO-PD-L1+ incubated with (g) MCLA-145, (h) urelumab* or (i) negative control antibody for 15 min, nuclear (DAPI) staining (blue), CD8 (green), CD137 (magenta). Single plane view, magnification ×20 (insets ×63). Data are representative of two repeat experiments for Fig. 6g–i.