Fig. 5. Bead phagocytosis induces NFB activation. (A) NFB (green) nuclear translocation was visualized by immunofluorescence 1 or 2 hours after the addition of anti-5 mAb-coated beads (red autofluorescence). Arrows mark cells positive for NFB translocation and with beads inside. Bar, 50 µm. (B) Activated NFB was detected by EMSA of nuclear extracts prepared from RSF incubated for 2 hours without beads (lane 5) or beads with anti-5 mAb-(lane 6) or beads coated with INV497 (lane 7). Lane 1, no extract; lane 2, HeLa extract; lane 3, HeLa extract plus 1.75 pmol of unlabelled specific probe; lane 4, HeLa extract plus 1.75 pmol nonspecific competitor.