Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
Leukocyte transendothelial migration during homing and inflammation requires drastic cell morphological changes, involving cytoskeletal-directed clustering of adhesion receptors in specialized protrusive membrane structures in leukocytes and endothelial cells. Extravasation is an active process not only for leukocytes but also for endothelial cells, which promote the rapid and efficient entry of leukocytes to the target tissues, without disturbing the integrity of the endothelial barrier. Herein, we have revised the specialized protrusive structures (microvilli, endothelial docking structures, leukocyte lamellipodia and uropod) involved in the different stages of leukocyte extravasation. The adhesion receptor redistribution, cytoskeletal remodelling and intracellular signaling events that participate in this phenomenon are also discussed.