Figure 8. Dendritic cell IL-2 regulates Treg suppression of CD4+ proliferation.

A: The Panels show proliferation of anti-CD3 stimulated CFSE-labeled C57BL/6 CD4⁺CD25⁻ Teff cells co-cultured with WT or IL-2^−/− KO (on B6 background) BMDCs, with and without C57BL/6 Treg cells at a Treg:Teff ratio of 2.5∶10. Numbers indicate percentage of Teffs that have divided. B: CD4⁺CD25⁻ Teff cell proliferation was measured by flow cytometry, and the % of Treg suppression of Teff cell proliferation was calculated as in materials and methods. Bars show percent Treg inhibition of proliferation of CD4⁺CD25⁻ Teff cells that were co-cultured with IL-2^−/− KO (gray) or WT (black) B6 BMDCs and Tregs at Treg:Teff ratio of 2.5∶10 (A) or 1∶10 (B–D), and stimulated as specified in columns A–D and materials and methods.