Suppression of naive alloresponses by IL-10/TGF-β–treated cells is not dependent on IL-10 and TGF-β MLR culture consisted of 10⁵ naive B6 CD4⁺ T-cell responders per well and 10⁵ bm12 splenic stimulators per well plated with and without B6 CD4⁺ T cells (2.5 × 10⁴ per well) that had been previously tolerized to bm12 alloantigen by an 8-day culture with IL-10 and TGF-β. Cultures were treated or not with IL-10, IL-10 receptor, and TGF-β neutralizing monoclonal antibodies (mAb). Shown is 1 of 5 representative experiments with similar results.