Fig. 4: Spermine-induced metabolic reprogramming and functional dysregulation of CD8⁺ T cells.

a Differential energy metabolism-related metabolites in CD8⁺ T cells treated with spermine (n = 3 biologically independent samples per group). b GSEA plots of mTORC1 and OXPHOS signaling based on RNA-seq of CD8⁺ T cells treated with spermine (n = 3 biologically independent samples per group). c Western blotting of mTOR, p-mTOR, S6K, pS6K, 4EBP1, and p-4EBP1 levels in CD8⁺ T cells treated with spermine (2 μM, 24 h). d Flow cytometric analysis of Ca²⁺ levels in the cytoplasm of CD8⁺ T cells. (n = 3 biologically independent samples). e Flow cytometric analysis of Ca²⁺ levels in the mitochondria of CD8⁺ T cells. (n = 3 biologically independent samples). f Representative images and quantification of mitochondria in CD8⁺ T cells (n = 5 biologically independent samples). Scale bars: 0.5 μm. g Representative images and quantification of MitoSOX in CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). Scale bars: 8 μm. h Representative images and quantification of JC-1 in CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). Scale bars: 8 μm. i Quantification of ATP levels in CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). j OCR data of CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). k ECAR data of CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). l Representative images and quantification of apoptosis in CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). m CFSE images and quantification of CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). n Flow cytometric analysis of Ki67, PD-1, Granzyme B, IFN-γ, TNF-α, and Perforin in CD8⁺ T cells treated with spermine (n = 3 biologically independent samples). For c n = 3 biologically independent samples. For f, data were presented as mean ± S.D., n = 5 biologically independent samples. For d, e, and g–n data were presented as mean ± S.D., n = 3 biologically independent samples. Statistical significance was determined using two-sided unpaired Student’s t-test or one-way ANOVA followed by Tukey’s post hoc test. Source data are provided as a Source Data file.