Suppressive capacity of CD4⁺CD25⁺ T cells is reduced at day 42, but is recovered by day 55. (A) Suppressive capacity of CD4⁺CD25⁺ T cells. On days 42 and 55 after the first injection of PG/DDA spleens were harvested. CD4⁺CD25⁺ and CD4⁺CD25⁻ T cells were FACS sorted, and the suppressive capacity of CD4⁺CD25⁺ cells on the proliferation of CD4⁺CD25⁻ T effector cells was tested in the presence of APCs and anti-CD3. Shown is percentage suppression of 3 mice per group (+ SEM). (B) Anergy of CD4⁺CD25⁺ T cells. Sorted CD4⁺CD25⁺ T cells were stimulated with 1 μg/mL soluble anti-CD3 for 96 hours and proliferation was measured by ³H incorporation. Three mice per group were used. Shown are stimulation indexes (SIs) of stimulation by anti-CD3 divided by culture in medium (+ SEM).