Strain specific PD-L1 expression analysis in homozygous B-hPD-L1/hCD27 mice by flow cytometry. Splenocytes were collected from WT and homozygous B-hPD-L1/hCD27 mice stimulated with anti-CD3ε in vivo, and analyzed by flow cytometry with species-specific anti-PD-L1 antibody. Mouse PD-L1 was exclusively detectable in WT mice. Human PD-L1 were exclusively detectable in B-hPD-L1/hCD27 but not WT mice.

Strain specific CD27 expression analysis in homozygous B-hPD-L1/hCD27 mice by flow cytometry. Splenocytes were collected from WT and homozygous B-hPD-L1/hCD27 mice stimulated with anti-CD3ε in vivo, and analyzed by flow cytometry with species-specific anti-CD27 antibody. Mouse CD27 was detectable in WT and B-hPD-L1/hCD27 mice. Human CD27 were exclusively detectable in B-hPD-L1/hCD27 but not WT mice. This might result from the cross-recognition of hCD27 by anti-mCD27 antibodies.