Fig. 4

Occurrence of CD127^lowPD-1^high T cells in an ex vivo model of T-cell receptor activation of purified T cells from healthy volunteers (n = 9). Purified T cells were activated with anti-CD3/28 antibody-coated beads (αCD3/28, 1:1 bead-to-cell ratio) or anti-CD3 antibody-coated beads (αCD3, 1:1 bead-to-cell ratio) or not stimulated (NS) during 5 days. The percentage of CD127^lowPD-1^high (a) as well as the percentage of HLA-DR (b) positive cells were measured by flow cytometry among CD4⁺ (left panel) and CD8⁺ (right panel) T cells. Data are presented as Tukey boxplots. Mann–Whitney paired tests were used to compare values between non-stimulated and activated conditions, *P <0.05, **P <0.01, ***P <0.001