Figure 4.

Capacity of β₂-integrin-deficient Tregs to suppress CD4⁺effector cell proliferation. In vitro suppression assays were performed as described previously [49] using wild-type CD4⁺CD25⁻ responder cells and wild-type CD4⁺CD25⁺ or β₂-integrin-deficient CD4⁺CD25⁺ Tregs. Cultures were stimulated with soluble anti-CD3 and anti-CD28 antibodies for 72 h and were pulsed with ³H-thymidine for the last 18 h. The results are shown as fold-increase over baseline controls for wild-type CD4⁺CD25⁻ cells alone (n=6), control CD4⁺CD25⁻ cells with wild-type CD4⁺CD25⁺ cells (n=17), and wild-type CD4⁺CD25⁻ cells with CD11a^−/− (n=6), CD11b^−/− (n=3), or CD11c^−/− (n=3) CD4⁺CD25⁺ cells.