Figure 4

CD4⁺CD25^low/-GITR⁺cells from HC and SLE patients express comparable levels of Treg markers . Treg-marker mRNA expression (fold increase expressed in a base 2 logarithmic scale) in CD4⁺CD25^low/-GITR⁺ and CD4⁺CD25^highGITR^- T cells from HC and SLE patients over the respective effector CD4⁺CD25^-GITR^- cell population arbitrarily set equal to 1 (A, B, left C, D). The levels of mRNA expression of genes in effectors from HC and SLE patients were similar. Bars indicate mean ± SEM. *P <0.05; **P <0.01' and ***P <0.001, according to Mann-Whitney U test comparing expression in Treg cell population (CD4⁺CD25^low/-GITR⁺ and CD4⁺CD25^highGITR^-) with the respective CD4⁺CD25^-GITR^- cell population. ^#P <0.05; ^##P <0.01; and ^###P <0.001, according to Mann-Whitney U test comparing expression in HC and SLE. (A, B, middle and right) Expression of FoxP3 (A) and CTLA-4 (B) in the indicated subpopulations was evaluated with flow cytometry. For CTLA-4 evaluation, cells were treated with 4 hours PMA plus ionomycin and monensin. Solid histogram represents isotype control. Results obtained with T cells from a representative SLE patient are shown. (A, B right) MFI ratios (MFI of Ab-stained cells/MFI of isotype-stained cells) are mean ± SEM (bars) of three SLE patients. *P >0.05, according to Mann-Whitney U test comparing expression in CD4⁺CD25^low/-GITR⁺ cell population with that in CD4⁺CD25^highGITR^- cell population. (E-G) Expression of CD45RO, CD45RA, and CD127 in the indicated subpopulations was evaluated with flow cytometry. Percentages of positive cells are mean ± SEM (bars) of three SLE patients. *P <0.05, according to Mann-Whitney U test comparing expression in Treg cell population (CD4⁺CD25^low/-GITR⁺ and CD4⁺CD25^highGITR^-) with that of CD4⁺CD25^-GITR^- cell population.