Extended Data Fig. 1. KineTACs target cell surface protein PD-L1 for degradation.
a, Representative western blot showing PD-L1 levels after 24 hr treatment of MDA-MB-231 cells with 100 nM of atezolizumab control, CXCL12 isotype, or CXCL12-Atz. b, Representative western blot showing PD-L1 levels after 24 hr treatment of MDA-MB-231 cells with 100 nM CXCL12-Atz or 100 nM CXCL12 isotype + 100 nM atezolizumab Fab. c, Flow cytometry showing degradation of surface PD-L1 on MDA-MB-231 cells after 24 hr treatment with 100 nM CXCL12-Atz, but not after addition of controls. d, Levels of cell surface and whole cell PD-L1 after 24 hr treatment of MDA-MB-231 cells with 100 nM CXCL12-Atz or atezolizumab Fab shows marginal differences between cell surface and whole cell PD-L1 levels. e, Representative western blot showing PD-L1 levels after 24 hr treatment of MDA-MB-231 cells with high concentrations (50–500 nM) of CXCL12-Atz shows that no ‘hook effect’ is observed in this concentration range. Data are representative of at least three independent biological replicates. Densitometry was used to calculate protein levels and normalized to PBS control.