In vitro inhibition of naive alloresponses by the addition of IL-10/TGF-β –tolerized cells. The addition of tolerized cells down-regulates a naive alloresponse in vitro. MLR culture consisted of 105 naive B6 CD4+ T-cell responders per well and 105 bm12 splenic stimulators per well plated with no, 104,3 × 104,or105 B6 CD4+ T cells that had been previously tolerized to bm12 alloantigen by an 8-day culture with IL-10 and TGF-β. Tolerized cells were washed free of cytokines prior to plating in regulatory cultures. To verify secondary hyporesponsiveness of tolerized cells, 105 tolerized cells were plated with 105 bm12 splenic stimulators per well. The y-axis presents the mean cpm ± 1 SE. On the x-axis are days in primary culture. Shown is 1 of 10 representative experiments.
