1. Amino acid residues in the PD-L1 IgV domain involved in PD-1 and/or B7-1 binding.
Amino acid residues in the PD-L1 IgV domain involved in PD-1 and/or B7-1 binding. A, Plasmids expressing a chimeric cell surface protein composed of the PD-L1 IgV domain (unmutated or mutated as indicated) and the TIM-3 mucin, transmembrane, and cytoplasmic domain were transfected into COS cells. After 48 to 60 hours, the cells were harvested and incubated with PD-1-hIg, B7-1-hIg, or human-Ig at 5 μg/mL. Binding of fusion protein was detected with goat anti-human IgG PE. Expression of the PD-L1-TIM-3 chimeric protein was detected with anti–TIM-3 specific for the TIM-3 mucin domain and goat anti-mIgG PE, and used to normalize the fusion protein binding as described in the Materials and Methods section. Data are representative of four independent experiments. Statistical analysis was done using one-way ANOVA and Dunnett test (unmutated vs. mutated; **, P ≤ 0.01; ***, P ≤ 0.001). Error bars, SEM. B, Mutated amino acids and their effect on binding are highlighted on the PD-L1 IgV structure (Lin et al., 2008).
Apoorvi Chaudhri et al. Cancer Immunol Res 2018;6:
©2018 by American Association for Cancer Research