Fig. 5: Spermine regulates the immunosuppressive function of TAMs through the TGF-β signaling pathway.

a Flow cytometric analysis of CD86, CD206, PD-L1, and RELMa in BMDMs and Raw cells treated with spermine (n = 3 biologically independent samples). b Flow cytometric analysis of Ca²⁺ levels in the mitochondria of BMDMs (n = 3 biologically independent samples). c GSEA plot of ETC and OXPHOS based on proteomic sequencing of BMDMs treated with spermine. d GSEA plot of purine metabolism based on proteomic sequencing of BMDMs treated with spermine. e Western blotting of ADA, GUK1, XDH, and IMPDH levels in BMDMs treated with spermine (10 μM, 24 h). f KEGG enrichment analysis of differentially expressed proteins in BMDMs treated with spermine, highlighting the top ten pathways (n = 3 biologically independent samples per group). g Western blotting of Smad2, p-Samd2, Smad3, and p-Smad3 levels in BMDMs treated with spermine (10 μM, 24 h). h Extracellular TGF-β levels in BMDMs treated with spermine (n = 3 biologically independent samples). i Schematic diagram illustrating the interaction between BMDMs and CD8 + T cells under the influence of spermine. j Flow cytometric analysis of CD206, PD-L1, and RELMa in BMDMs (n = 3 biologically independent samples). k OCR data of CD8⁺ T cells (n = 3 biologically independent samples). l CFSE images and quantification of CD8⁺ T cells (n = 3 biologically independent samples). m Flow cytometric analysis of Ki67, PD-1, GZMB, IFN-γ, TNF-α, and Perforin in CD8⁺ T cells (n = 3 biologically independent samples). For a, b, h, j–m data were presented as mean ± S.D., n = 3 biologically independent samples. For e and g, 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. Panel i was created in part with BioRender. Hanshen, Y. (https://BioRender.com/rbvmrne). Source data are provided as a Source Data file.