Fig. 2: PD-1 represses mTOR and HIF1α in premalignant cells.
a, Whole-body standardized uptake value (SUV) maps from [18F]FDG PET measurements of C57BL/6 mice, ITK-SYKCD4-CreERT2 and ITK-SYKCD4-CreERT2;Pdcd1−/− mice together with anatomical MRI acquisition. The [18F]FDG PET measurements were conducted on day 5 after tamoxifen application. Magnified [18F]FDG PET signals from lymph nodes are shown (insets). White arrows indicate spleens. Color intensity represents the calculated uptake of [18F]FDG in units of MBq ml−1. b, SUVmax for the indicated genotypes (n = 3 for C57BL/6, n = 9 for Pdcd1+/+ and n = 6 for Pdcd1−/− mice) from the experiment shown in a. SUVmax denotes the maximum signal found in a single voxel across the entire tumor lesion. P, one-way ANOVA and two-sided Student’s t-test. Shown are the mean ± s.e.m. and individual data points. c, Exemplary 7-T MRI chemical shift imaging (CSI)-derived 13C magnetic resonance spectra showing [1-13C]pyruvate and [1-13C]lactate amplitudes in the splenic region of interest of ITK-SYKCD4-CreERT2 and ITK-SYKCD4-CreERT2;Pdcd1−/− mice following injection of hyperpolarized [1-13C]pyruvate on day 5 after tamoxifen injection. AU, arbitrary units. d, Ratio of [1-13C]pyruvate and [1-13C]lactate amplitudes in spleens measured by 7-T MRI in ITK-SYKCD4-CreERT2 and ITK-SYKCD4-CreERT2;Pdcd1−/− mice on day 5 after tamoxifen injection (n = 3 mice per genotype). P, two-sided Student’s t-test. Shown are the mean ± s.d. and individual data points. e, Flow cytometry for p-AKTS473, p-mTORS2448, HIF1α, GLUT1 and hexokinase 2 in ITK–SYK-expressing T cells. Spleen-derived single-cell suspensions were generated from ITK-SYKCD4-CreERT2 mice on day 5 after tamoxifen injection. Before fixation, anti-PD-L1 or control antibodies were added for 4 h in vitro. f, Survival of ITK–SYK+PD-1− lymphoma-bearing NSG mice treated with torin-1 or vehicle. On day 0, NSG mice received 1,000 ITK–SYK-expressing eGFP+ cells from an ITK-SYKCD4-CreERT2;Pdcd1−/− mouse, sorted by flow cytometry on day 5 after tamoxifen injection. Mice received 6 mg per kg torin-1 or vehicle daily via intraperitoneal injection (n = 6 mice per group) from day 3 post tamoxifen on. P, two-sided log-rank test. a, Representative mice from two independent experiments. b, Pooled data from two independent experiments. c, Representative amplitudes from one experiment. d, Pooled data from two independent experiments. e, Representative data from two independent experiments with two biological replicates per group. f, Pooled data from two independent experiments.
