Fig. 3.

Influence of IL-2 family cytokines on Treg viability. Purified, naïve Tregs (2×10⁴) were cultured with plate-bound anti-CD3 antibody and the indicated cytokines. After 72 h, the number of total live cells (A) and the viability of the cultures, as determined by Trypan blue staining (B), were enumerated. White bars, Freshly isolated Tregs; shaded bars, freshly isolated Tregs with immobilized anti-CD3 antibody; black bars, 3-day-preactivated Tregs. Significance was tested using a Student’s t-test by comparing the cytokine-treated culture with the same population of untreated cells [without cytokine (w/o)]: ***, P < 0.001; **, P < 0.01; *, P < 0.05. The mean ± sd of triplicates of one of two similar experiments is shown. ns, Not significant.