Fig. 8. Uptake of anti-ICAM-1 immunobeads requires actin regulatory proteins. TNF- activated HUVEC were treated for 30 minutes with vehicle alone (A), 10 µM latrunculin A, 20 µM nocodazole, 10 µM radicicol (B), 10 µM Y-27632 (C) or 0.5 µM wortmannin (D), then incubated with anti-ICAM-1 immunobeads for 1 hour at 37°C, then fixed and immunostained to double-label surface-bound material (yellow, arrowheads). Arrows denote internalized immunobeads. Uptake of anti-ICAM-1 immunobeads was quantified as mean±s.d. by fluorescence microscopy for these treatments, expressed as a percentage of immunobead uptake. Uptake required both Src kinase activity and ROCK activity, since it was inhibited by radicicol and Y27632, but did not appear to require PI-3 kinase activity, as wortmannin had no measurable effect on uptake. *P<0.05.