Figure 5. USP21-ΔTreg cells have compromised expression of Treg signature genes and impaired suppressive activity.

(a) Scatter plot of genes significantly upregulated (yellow), downregulated (blue) or unchanged in USP21-ΔTreg cells. The cutoff value was set at fold change≥2 and P value<2.2e−16. (b) Clustering of differentially expressed genes identified in USP21-ΔTreg cells compared with WT Treg cells. Yellow and purple represent high and low levels of expression of the indicated genes, respectively. The colours indicate the value of log₂ fold change. (c) Percentage of FOXP3-bound genes that changed in expression in USP21-ΔTreg cells, where published FOXP3 ChIP-seq data sets were used as total FOXP3 target gene coverage. (d) CD4⁺CD25⁻YFP⁻ Teff cells were sorted from WT mice and labelled with CellTrace Violet. Labelled responder T cells were then either cultured alone or mixed with varying amounts (as indicated) of CD4⁺CD25^hiYFP⁺ Treg cells sorted from WT or KO mice. Cell mixtures were stimulated with anti-CD3/CD28 beads and the proliferation of the responder cells was measured three days later. (e) Percentage of proliferated responder T cells was assessed as shown in d. (n=3 for each group). All data represent means±s.d. *P≤0.05, **P≤0.01, as determined by Student's t-test. NS, not significant.