The L-selectin adhesion system.

L-selectin is a cell surface glycoprotein expressed on most leukocyte subsets that mediates leukocyte interaction with ligands on lymphoid tissue high endothelial venule cells as well as with ligands on activated endothelium at sites of inflammation in nonlymphoid organs. Similar to two other members of the selectin family, L-selectin behaves as a lectin, recognizing carbohydrate ligands in a calcium-dependent fashion. Recent in vivo studies reveal the importance of L-selectin expression in both normal and pathologic conditions.