Sialyl-Lewis X

Sialyl lewis x

Sialyl-Lewis X

Sialyl-Lewis X is a type of sialylated oligosaccharide that plays a crucial role in cell adhesion processes, particularly in the context of inflammation and immune responses. It is a carbohydrate structure that is commonly found on the surface of certain cells, where it acts as a ligand for selectins, a group of cell adhesion molecules involved in the recruitment of leukocytes to sites of inflammation.

Structure

Sialyl-Lewis X is composed of a core structure of fucose linked to N-acetylglucosamine and sialic acid. The presence of sialic acid and fucose residues confers specific binding properties to the molecule, allowing it to interact with selectins on the surface of endothelial cells and leukocytes.

Function

The interaction between Sialyl-Lewis X and selectins is a key step in the process of leukocyte recruitment to sites of inflammation. Selectins expressed on the surface of endothelial cells bind to Sialyl-Lewis X on the surface of circulating leukocytes, leading to the tethering and rolling of these cells along the endothelium. This initial interaction is essential for the subsequent firm adhesion and transmigration of leukocytes into the inflamed tissue.

Clinical Significance

Aberrant expression of Sialyl-Lewis X has been implicated in various pathological conditions, including inflammatory diseases and cancer metastasis. Targeting the interaction between Sialyl-Lewis X and selectins has emerged as a potential therapeutic strategy for modulating immune responses and inhibiting the spread of cancer cells.

See Also

• Selectin
• Oligosaccharide
• Inflammation