Effect of proteasome inhibitors on NF-κB activation induced by β2 integrin triggering.
(A) Nonadherent monocytes (10-15 × 106 cells) were not preincubated (lanes 1, 2, 4, 6, 8, 9) or were preincubated with 100 μM PSI for 1 hour (lanes 3, 5, 7, and 10) and then stimulated with medium alone (lanes 1 and 8), anti-CD11b mAb (10 μg/mL; lanes 2 and 3), anti-CD11c mAb (10 μg/mL; lanes 4 and 5), ZZ-CD23 (5 μg/mL; lanes 6 and 7), or MBP-CD23 (2 μg/mL; lanes 9 and 10) for 30 minutes. (B) Nonadherent monocytes were pretreated with increasing amounts of ALLN (2, 20, and 100 μM) for 1 hour (lanes 3-5 and 8-10) and then stimulated with mAbs to CD11b (10 μg/mL) or CD11c (10 μg/mL) for 30 minutes. (C) Nonadherent monocytes were incubated for 1 hour without ALLN (lanes 1, 2, 4, and 5) or with 100 μM ALLN (lanes 3 and 6) before stimulation for 30 minutes with ZZ-CD23 (5 μg/mL; lanes 2 and 3), MBP-CD23 (2 μg/mL; lanes 5 and 6), or medium alone (lanes 1 and 4). Nuclear extracts were prepared and analyzed for NF-κB DNA-binding activity in bandshift experiments. Results are representative of 3 similar experiments.
