L-selectin
Encyclopedia
L-selectin, also known as CD62L, is a cell adhesion molecule
found on leukocytes. It belongs to the selectin
family of proteins, which recognize sialylated carbohydrate groups. It is cleaved by ADAM17
.
s present on endothelial cells will bind to leukocyte expressing L-selectin, slowing leukocyte trafficking through the blood, and facilitating entry into a secondary lymphoid organ at that point. The receptor is commonly found on the cell surfaces of T cells. Naive T-lymphocytes, which have not yet encountered their specific antigen, need to enter secondary lymph nodes to encounter their antigen. Central memory T-lymphocytes, which have encountered antigen, express L-selectin to localize in secondary lymphoid organs. Here they reside ready to proliferate upon re-encountering antigen. Effector/memory T-lymphocytes do not express L-selectin, as they circulate in the periphery and have immediate effector functions upon encountering antigen.
Cell adhesion molecule
Cell Adhesion Molecules are proteins located on the cell surface involved with the binding with other cells or with the extracellular matrix in the process called cell adhesion....
found on leukocytes. It belongs to the selectin
Selectin
Selectins are a family of cell adhesion molecules . All selectins are single-chain transmembrane glycoproteins that share similar properties to C-type lectins due to a related amino terminus and calcium-dependent binding...
family of proteins, which recognize sialylated carbohydrate groups. It is cleaved by ADAM17
ADAM17
ADAM metallopeptidase domain 17 , also called TACE , is a 70-kDa enzyme that belongs to the ADAM protein family of disintegrins and metalloproteases.- Chemical characteristics :...
.
Ligands
- GlyCAM-1, found in the high endothelial venules of the lymph nodeLymph nodeA lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
s. - CD34CD34CD34 molecule is a cluster of differentiation molecule present on certain cells within the human body. It is a cell surface glycoprotein and functions as a cell-cell adhesion factor. It may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells...
, found on endothelial cells. - MadCAM-1, found on endothelial cells of gut-associated lymphoid tissueGut-associated lymphoid tissueThe digestive tract's immune system is often referred to as gut-associated lymphoid tissue and works to protect the body from invasion. GALT is an example of mucosa-associated lymphoid tissue.-Function:...
. - PSGL-1, binds with low affinity.
Function
L-selectin acts as a "homing receptor" for leukocytes to enter secondary lymphoid tissues via high endothelial venules. LigandLigand
In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex. The bonding between metal and ligand generally involves formal donation of one or more of the ligand's electron pairs. The nature of metal-ligand bonding can range from...
s present on endothelial cells will bind to leukocyte expressing L-selectin, slowing leukocyte trafficking through the blood, and facilitating entry into a secondary lymphoid organ at that point. The receptor is commonly found on the cell surfaces of T cells. Naive T-lymphocytes, which have not yet encountered their specific antigen, need to enter secondary lymph nodes to encounter their antigen. Central memory T-lymphocytes, which have encountered antigen, express L-selectin to localize in secondary lymphoid organs. Here they reside ready to proliferate upon re-encountering antigen. Effector/memory T-lymphocytes do not express L-selectin, as they circulate in the periphery and have immediate effector functions upon encountering antigen.