L-Selectin

L-selectin (CD62L) is a type I transmembrane cell adhesion molecule expressed on most circulating leukocytes, including neutrophils. L-selectin recognizes sialylated carbohydrate groups containing a Sialyl LewisX (sLeX) determinant predominantly N-linked to L-selectin. L-selectin on human neutrophils is itself decorated with sLeX, it can act as a ligand for E-selectin. L-selectin engaged with endothelial-derived ligands initiates neutrophil tethering and rolling behavior along luminal walls of post-capillary venules, constituting the first step of the multi-step adhesion cascade. Blocking the shedding of L-selectin can profoundly alter cell polarity in monocytes entering the subendothelial space^[1].