Figure 7

In SLE patients, the regulatory activity exerted by CD4⁺CD25^low/-GITR⁺cells is higher than CD4⁺CD25^highGITR^-cells . CFSE-labeled effector T cells from SLE (A) or HC (B) patients, activated with cross-linked anti-CD3 Ab, were co-cultured with heterologous unlabeled effector (CD4⁺CD25^-GITR^-) (left, A and B), heterologous unlabeled CD25-depleted (including CD4⁺CD25^-GITR^- and CD4⁺CD25^low/-GITR⁺) (middle, A and B) or heterologous unlabeled GITR-depleted (including CD4⁺CD25^-GITR^- and CD4⁺CD25^highGITR^-) cells (right, A and B) at a 1:3 cell ratio from HC (A) or SLE patients (B). Proliferation was evaluated after 4 days with flow cytometry. Experiments with cells from two representative SLE patients co-cultured with cells from two representative HCs are shown. Graphs show inhibition of proliferation by CD4⁺CD25^low/-GITR⁺ and CD4⁺CD25^highGITR^- (histograms) and the differences between the inhibition (plots) in each subject (A, B). (C) CFSE-labeled effector T cells from HC, activated with cross-linked anti-CD3 Ab, were co-cultured with HC (left) or SLE (middle right) unlabeled effector (CD4⁺CD25^-GITR^-) or HC (middle left) or SLE (right) unlabeled CD25-depleted (including CD4⁺CD25^-GITR^- and CD4⁺CD25^low/-GITR⁺) cells at a 1:3 cell ratio. Histogram show inhibition of proliferation of labeled HC effector by HC and SLE CD4⁺CD25^low/-GITR⁺ cells. (D) Correlation between levels of CD4⁺CD25^low/-GITR⁺ in CD4⁺ cells purified from HC and SLE patients and inhibition of proliferation by CD4⁺CD25^low/-GITR⁺ cells from the same subjects (CD4⁺CD25^low/-GITR⁺ cells from SLE patients; Spearman ρ =0.77, P =0.10; CD4⁺CD25^low/-GITR⁺ cells from HC, Spearman ρ = -0.71, P =0.13).