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Fig. 5. Localization of `activated'
vß3 in
resorbing OC. Primary human OCs were plated onto bone slices in the presence
of 10% FBS and stained by double immunofluorescence with the
anti-ß3 mAb AP5, which recognizes only the `activated'
integrin conformation, followed by cyanine-3-conjugated rabbit anti-mouse IgG
(A,C,E) and by fluorescein-tagged phalloidin (B,D,F). Microscopic images show
the three different axial sections indicated in
Fig. 3A: at the level of the
sealing zone (SZ), the `activated' ß3 (A) only partially
colocalizes with the actin ring (B) and displays a discrete pattern. In the
ruffled border area (RB) the `activated' ß3 (C) is very
abundant with a punctuate distribution similar to that of the actin
microfilaments of D. In the optical yz-plane, note the presence of the actin
in the sealing zone SZ (F) as a line at the edge of the cell that only
partially colocalizes with the integrin detected by AP5 (E). By contrast, the
`activated' receptor and the actin are both present in the ruffled border area
RB. Bar, 5 µm.