L-Selectin ELISA

L-selectin (Leukocyte-Endothelial Cell Adhesion Molecule-1) belongs to the selectin family of adhesion molecules. Together with ELAM-1 (E-selectin) and GMP-140 (P-selectin) L-selectin mediates the initial interactions of leukocytes with endothelial cells. Selectins guide non-activated polymorphonuclear cells to the areas of inflammation in creating first, loose contacts with the endothelial layer. L-selectin in this aspect mediates rolling of PMN's on endothelial cells. The potential binding partners of L-selectin carry a negative charge, probably a sialic acid and/or sulphate, and may contain mannose and fucose. In addition, L-selectin may also interact with ELAM-1 which is expressed on cytokine-activated endothelial cells. L-selectin is constitutively expressed on most leukocytes (PMN's, monocytes, lymphocyte subsets) in a seemingly functional form. It is required for the binding of lymphocytes to the high endothelial venules of peripheral lymph nodes (and therefore serves as a lymphocyte recirculating receptor) and for the invasion of neutrophils into sites of inflammation. When neutrophils are activated, L-selectin is shed by proteolytic cleveage near the transmembrane span. Lymphocytes and monocytes can also shed L-selectin upon activation although the kinetics are significantly lower. A broad range of activating agents including C5a, fMLP, TNF, GM-CSF, IL-8 are effective in inducing this response. The shed form of L-selectin (sL-selectin) is functionally active and at high concentrations can inhibit leukocyte attachment to endothelium. The main source for sL-selectin in serum seems to be tissue localized leukocytes. Determination of soluble/circulating L-selectin could provide more detailed insights into the pathological modifications during various diseases (allergy, deep venous thrombosis, HIV, insulin-dependent diabetes mellitus, Kawasaki Syndrome, malignant B-cell populations, neonatal bacterial infection, sepsis, surgery). Synonyms: Leukocyte-Endothelial Cell Adhesion Molecule-1, CD62L, LECAM-1, MEL-14 antigen, LAM-1, LEU-8 antigen, TQ1 antigen