Figure 6.

Impaired suppressive function of regulatory T cells (Tregs) from kidney transplant patients. (A) Histograms show cells proliferation of carboxy fluorescein succinimidyl ester (CFSE)-labeled CD3⁺ T cells in the absence (responder T cells alone) or presence of Tregs (CD4⁺CD25^veryhi gated) from kidney transplant patients (BLT and CsA) or healthy subjects (control), numbers indicate the percentage of dividing cells. One representative experiment is presented. (B) CD4⁺CD25^hi T cells (Treg) isolated from BLT- (black bars, n = 9) or CsA- (gray bars, n = 4) treated patients showed impaired suppression of both autologous responder CD4⁺ and CD8⁺ T cell (Tresp) proliferation at all evaluated Tregs:Tresp ratios, compared to controls (white bars, n = 8). There were no significant differences between Tregs from BLT- and CsA-treated patients. Suppression was calculated as relative inhibition using the following formula: [(Tresp proliferation without Tregs − Tresp proliferation with Tregs)/Tresp proliferation without Tregs] × 100. Statistical analysis was performed using non-parametric Mann–Whitney test, two tailed. BLT, belatacept; CsA, Cyclosporine A.