MDM2 inhibition promotes cytotoxicity and longevity of donor T cells. (A-H) Scatterplots and representative histograms show expression of (A-B) perforin, (C-D) CD107a, (E-F) IFN-γ, and (G-H) TNF of CD8⁺ T cells isolated from the spleen on day 12 following allo-HCT of WEHI-3B leukemia-bearing BALB/c mice transplanted with C57BL/6 BM plus allogeneic C57BL/6 T cells and treated with either vehicle or MDM2 inhibitor RG-7112. Mean value ± standard error of the mean (SEM) from n = 14 to 19 biologically independent animals per group from 2 experiments are shown, and P values were calculated using the 2-sided Mann-Whitney U test. (I) UMAP showing the FlowSOM-guided manual metaclustering of splenic live CD45⁺ cells from leukemia-bearing BALB/c mice after allo-HCT. (J) UMAP showing the FlowSOM-guided manual metaclustering (top) and heatmap showing median marker expression (bottom) of donor-derived (H-2kb⁺) TCRβ⁺ CD8⁺ T cells from leukemia-bearing BALB/c mice after allo-HCT treated with RG-7112 or vehicle, as indicated. (K) Quantification of donor-derived (H-2kb⁺) TCRβ⁺ CD8⁺ CD27⁺ TIM3⁺ T cells from leukemia-bearing BALB/c mice after allo-HCT treated with RG-7112 or vehicle, as indicated. (L-O) Scatterplots and representative histograms show expression of (L-M) CD127 and (N-O) Bcl-2 of CD8⁺ T cells isolated from spleen on day 12 following allo-HCT of WEHI-3B leukemia-bearing BALB/c mice transplanted with C57BL/6 BM plus allogeneic C57BL/6 T cells and treated with either vehicle or MDM2 inhibitor RG-7112. Mean value ± SEM from n = 14 to 19 biologically independent animals per group from 2 experiments are shown. P value was calculated using the 2-sided Mann-Whitney U test.