Fig. 1. UDCA inhibits tumor progression by modulating Treg cells.

a, b Tumor sizes and mouse survival (a) and flow cytometric (FC) analysis of CD4⁺CD25⁺Foxp3⁺ Treg cells, total CD8⁺ T cells and the corresponding CD4⁺ and CD8⁺ T cell subsets among TILs on day 18 (b) in B16-F10, MC38 (a) and LLC (a, b) tumor-bearing mice that received intraperitoneal (i.p.) injection of 30 mg kg⁻¹ UDCA every 2 days. c–e Tumor sizes and mouse survival (c) and FC analysis of CD8⁺CD45⁺ T cells and Foxp3⁺CD4⁺CD45⁺ T cells among TILs on day 18 (d, e) in LLC tumor-bearing mice treated with UDCA along with 100 μg of anti-CD25 (c, d) or 40 μg of anti-CD8-neutralizing antibodies (anti-CD8) (e) every 3 days. f ELISA of TGF-β1, TGF-β2, and TGF-β3 in serum and tumor tissues of UDCA-treated LLC tumor-bearing mice on day 9. g, h Tumor sizes and mouse survival (g) and FC analysis of CD4⁺CD25⁺Foxp3⁺ Treg cells and CD8⁺CD45⁺ T cells among TILs on day 18 (h) in LLC tumor-bearing Tgfbr2^f/fEr-cre mice treated with UDCA. i FC analysis of the proliferation of CFSE-labeled CD4⁺ or CD8⁺ T cells cocultured with CD4⁺CD25⁺ Treg cells isolated from the spleens of UDCA-treated LLC tumor-bearing mice on day 18. Cells were cultured at a T cell:Treg cell ratio of 4:1 in anti-CD3 and anti-CD28-coated plates for 5 days. Representative results from three independent experiments are shown (n = 5 in (a, c, f, g); n = 3 in (b, d, e, h, i). *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant (unpaired two-tailed Student’s t test except for log-rank test for survival rate analysis; mean and s.d.). See Source Data file for the exact P-values.