Leukocyte trans-endothelial migration: JAMs add new pieces to the puzzle.

The molecular details of leukocyte transmigration through the endothelial barrier (also called diapedesis), which is the final step of leukocyte extravasation from the circulation to a given site of inflammation, are by far not well understood. The present review will focus on the different mechanisms potentially involved in leukocyte trans-endothelial migration. Both homophilic and heterophilic interactions between leukocyte and endothelial cell receptors will be covered, with a particular focus on the growing gene family of junctional adhesion molecules (JAM). Deciphering their mechanisms of interaction will also allow to unravel novel strategies for therapeutic intervention in inflammatory or atherothrombotic diseases.