FIG 7.

Pure recombinant M2 protein recapitulates IF activities on B7–CTLA4/CD28/PD-L1 interactions. The effect of the purified M2 protein on CD28-CD80 (A), CD28-CD86 (B), PD-L1–CD80 (C), CTLA4-CD80 (D), and CTLA4-CD86 (E) interactions was compared to those of ipilimumab (Yervoy), recombinant hCTLA4-Fc, anti-hCD80 monoclonal antibody (MAb B7-1), and anti-hCD86 monoclonal antibody (MAb B7-2) as well as with the supernatant collected from CEF cells infected with TK⁻ RR⁻ Copenhagen vaccinia virus (VV-DD) in the case of the CTLA4-CD80 interaction. Binding of His-tagged B7-Fc proteins to immobilized CTLA4-Fc, CD28-Fc, or PD-L1–Fc was monitored using an HRP-conjugated anti-His antibody. Each represented value is the mean (± standard deviation) of three measurements.