CD4⁺CD25⁺ cells are not required for the induction of tolerance to alloantigen via 8-day MLR culture with IL-10 and TGF-β (A) Primary MLR consisted of 0.5 × 10⁶/mL B6 CD4⁺CD25^– T-cell responders (≥ 99.6% pure) and 0.5 × 10⁶/mL bm12 splenic stimulators cultured for 8 days with IL-10 and TGF-β. Control MLR was not treated with cytokines. (B) To measure tolerance induction of CD4⁺CD25^– cells by IL-10/TGF-β, the CD4⁺ T cells were recovered after an 8-day primary MLR culture period, washed, and restimulated with fresh bm12 splenic stimulators. Shown is 1 of 4 representative experiments with similar results.