Effect of TB antigen and MEK inhibition on FoxP3 expression in resting and activated Tregs in TB patient samples.

(a) Gating strategy for resting (CD4⁺CD45RA⁺FoxP3⁺) and activated (CD4⁺CD45RA⁻FoxP3⁺⁺) Tregs. (b) PBMCs were stimulated with ESAT-6/Ag85 for 36 h in presence or absence of 100 nM MEK inhibitor GSK1120212 or left untreated. Effect of GSK1120212 (100 nM and 10 μM) on FoxP3 expression levels (MFI) (c, e) and number of FoxP3⁺ cells (%) (d, f) in resting (c, d) and activated (e, f) CD4⁺Tregs stimulated with ESAT-6/Ag85. (g) Ratio of aTreg over rTreg (%) in samples stimulated with ESAT-6/Ag85 alone and at two different MEKI concentrations as in d and e. (Boxes: median ± 25^th to 75^th percentile; whiskers: min to max, n = 12, * p< 0.05, ** p<0.01, *** p< 0.001).