Crossing the Vascular Wall: Common and Unique Mechanisms Exploited by Different Leukocyte Subsets during Extravasation

Figure 1

General scheme of the leukocyte extravasation cascade. The different steps of leukocyte interactions with endothelial cells during adhesion and transmigration are depicted. The known adhesion receptor interactions are listed for each step with the leukocyte receptor being named first. Unknown ligands are represented by question marks. During rolling, secondary rolling of leukocytes on already adherent leukocytes can occur that involve interactions of leukocyte L-selectin with leukocyte PSGL1 (not depicted). All receptors are connected to the actin cytoskeleton via actin-binding proteins to facilitate the extensive actin remodeling required for the morphological changes and movement of both cell types involved (not depicted). For details, see text.