Bcl-3 promotes survival of DCs. (A) WT and Bcl-3−/− BMDCs were stimulated with LPS (100ng/ml) for 24h and analyzed with RT2 profiler apoptosis superarray. Mean of fold-change for n=5 mice/group. (B) WT and Bcl3−/− BMDCs were treated and co-cultured with OT-II as in Figure 1A (standard conditions). Cells were stained for CD11c, Annexin V and 7-AAD and analyzed by flow cytometry after gating on CD11c. Representative FACS plot in top panels and % live and apoptotic BMDCs in bottom panels; mean ±SEM, 4 experiments with n=12 mice/group. (C) WT and Bcl3−/− BMDCs were treated and co-cultured with OT-II (24, 48 or 72h) and BMDCs analyzed as in (B). Mean of % live cells ±SEM, n=3/group (additional experiment yielded similar results). (D) WT and Bcl3−/− BMDCs were treated and co-cultured with OT-II cells as in (B) and CD11c-gated BMDCs assayed for caspase-3 activity. Mean ±SEM, n=3 mice/group (additional experiment yielded similar results). (E) WT and Bcl-3−/− and (F) WT and Bcl-3-Δ-DC mice were injected with LPS (30μg) or PBS i.v., splenocytes isolated 48h later and stained for CD11c and MHC-II. Absolute DC numbers shown as mean ±SEM; n=5-8 mice/group, based on 2 experiments. (G) WT and Bcl-3-Δ-DC mice were treated as in (E,F) and spleen sections stained for TUNEL+ cells. Representative sections shown in left panels and data summarized in right panel; mean of counts/section area ±SEM; n=4 mice/group with blinded analysis of 5 random sections/mouse. *P<0.05, **P<0.01 and ***P<0.0001.