Sialyl-Lewis X antigen (sLeX)

Sialyl-Lewis X antigen (sLeX) is a tetrasaccharide carbohydrate structure (Neu5Acα2-3Galβ1-4[Fucα1-3]GlcNAcβ) found primarily attached to cell surface glycoproteins and glycolipids. It serves as a crucial recognition molecule for selectins, enabling physiological processes such as leukocyte adhesion and rolling during inflammation and immune surveillance. sLeX is also involved in pathological states including cancer metastasis, where increased expression on tumor cells facilitates their interaction with endothelial selectins, aiding in dissemination. sLeX functions as a blood group antigen, is known under several other names (CD15s, SSEA-1), and is prominent in immune cell trafficking and fertilization. While not a protein, enzyme, or receptor, sLeX is a key glycan epitope of great biological and clinical significance[1][3][4][5][6].

Other names

Sialyl-Lewis XsLeXCD15sstage-specific embryonic antigen 1 (SSEA-1)Sialyl Lewis X antigensialyl-LeXsialyl-Lewis X determinant

Therapeutics interact either by inhibiting sLeX-mediated adhesion to selectins (selectin antagonists) or by blocking sLeX directly with antibodies; the intent is to prevent cell adhesion, rolling, or metastasis