Fig. 4.

Effector differentiation of CD8⁺ T cells induces IL-2–dependent Treg expansion. (A) CD45.1⁺ OT-I or CD45.1⁺ gBT-I T cells were transferred to nTx or sham-Tx 11c.OVA mice treated with anti-CD25 or isotype control mAb. At the indicated time points, spleens were collected and the number of CD4⁺CD25⁺FoxP3⁺ Treg determined by FACS counting assay. (B) CD45.1⁺ OT-I or CD45.1⁺ gBT-I T cells were transferred to nTx 11c.OVA mice treated with anti–IL-2 (JES6.1 plus S4B6) or PBS, as indicated. Three days after transfer, spleens were collected and the number of CD4⁺CD25⁺FoxP3⁺ Treg determined by flow cytometry. Data are (A) mean ± SD (n = 4–7 per group) or (B) individual values pooled from two to three experiments.