Figure 2.

Leukocyte and static bead transmigration. Protrusive membranes (Endothelial protrusions, indicated by the arrowheads) arise from the apical endothelial surface and surround a leukocyte (A) or a static bead (B). The protrusions are believed to assist the leukocyte on its way through and limit vascular leakage. The image on the left may represent a transcellular event with the leukocyte on its way through the endothelial cell border, although the openings at the endothelial level may also suggest that this is a paracellular event. Scale bar: 10 μm.