Fig. 2

Lactate inhibition impairs the suppressive activity of murine MSCs on proinflammatory Th1 and Th17 cells. A Colorimetric measure of L-Lactate produced by control MSCs (gray bar), MSC_GF (orange bar), and MSC_siLDHA (yellow bar) after 24 h of treatment. B–I Naive CD4⁺ T cells from C57/BL6 mice were marked with CTV and stimulated to differentiate into Th1 (B–E) or Th17 (F–I) cells and cultured alone (light and dark red, respectively) or with control MSCs (gray bar) or pretreated with galloflavin (orange bar) or LDHA-siRNA (yellow bar) to inhibit lactate production. After 3 days of co-culture, proliferation of Th1 (B, C) and Th17 (F, G) cells, and IFNγ (D, E) or IL-17A (H, I) production were evaluated by FACS. Results represent the mean ± SD of three independent experiments lactate measurement and three independent experiments with at least six different biological samples for CD4⁺ T cells; *p < 0.05, **p < 0.01, ***p < 0.001 (unpaired Kruskal–Wallis test). Unless otherwise indicated, comparisons were with MSC in basal or control conditions, or with Th1 or Th17 cells