Figure 3 from IFNγ Production by Functionally Reprogrammed Tregs Promotes Antitumor Efficacy of OX40/CD137 Bispecific Agonist Therapy

OX40/CD137 dual agonism results in decreased CD25 expression and IL2 responsiveness of Tregs. A, Representative histograms and replicate measurements showing CD25 expression on CD4⁺ Tregs from the spleen (left) and tumor-draining lymph node (right). B, Schema showing setup of ex vivo IL2 assay (left), replicate measurements of Foxp3-GFP expression (center), and Treg count (right) after 4 days in culture with the indicated concentrations of IL2. C, Schema representing treatment schedule of tamoxifen, FS120m, and rIL2/anti-IL2 mAb complex. D, Representative plots (left) and replicate measurements (right) of the percentage of RFP⁺ SP exTregs (GFP⁻) out of total RFP⁺ cells in the tumors and spleens of reporter mice treated according to C. Data were analyzed by unpaired Student t test (A), unpaired Student t test with Bonferroni–Dunn correction for multiple comparisons (B), and one-way ANOVA with Tukey correction for multiple comparisons (D). Bars and error are mean and SEM. *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.0001; ****, P ≤ 0.0001. Ctrl, control; dLN, tumor-draining lymph node.