Elicited but not resident peritoneal macrophages from Daf^−/− mice are more potent T-cell stimulators than similarly harvested WT mouse macrophages. (A) FACS analysis showing that resident peritoneal macrophages from WT but not Daf^−/− mice expressed DAF (left panel). No difference was observed between resident peritoneal macrophages of WT and Daf^−/− mice in their ability to stimulate OT-II CD4⁺ or OT-I CD8⁺ T cells as measured by IFN-γ production. NS indicates not significant. P > .05. (B) Thioglycollate-elicited peritoneal macrophages from Daf^−/− mice were more potent than similarly harvested WT macrophages in stimulating OT-II CD4⁺ or OT-I CD8⁺ T cells as measured by IFN-γ production. *P < .05. (C) FACS (left panel) and Western blot (right panel) analysis showing that DAF was completely down-regulated on thioglycollate-elicited WT mouse peritoneal macrophages. Lane designation in right panel: Lanes 1 and 6, WT splenocytes; lane 2, WT resident peritoneal macrophages; lane 3, Daf^−/− resident peritoneal macrophages; lane 4, WT thioglycollate-elicited peritoneal macrophages; lane 5, Daf^−/− thioglycollate-elicited peritoneal macrophages. Except Western blot data, all results are representatives of 5 independent experiments.