sLeXsLeA

sLeXsLeA is a term used in glycoscience to describe a glycan motif that combines the sialyl Lewis X (sLe^x) and sialyl Lewis A (sLe^a) epitopes on one or adjacent glycans of a glycoprotein or glycolipid. The concept is used to refer to glycoconjugates that display both Lewis antigen types, which may occur naturally in cells or be created in glycoengineering experiments.

sLe^x and sLe^a are small, sialylated, fucosylated carbohydrates that function as ligands for selectins, a family of adhesion receptors. sLe^x is typically recognized by E- and P-selectin and is associated with leukocyte trafficking and inflammation; sLe^a is best known as a tumor-associated antigen and a marker for pancreatic cancer (CA19-9). The sLeXsLeA motif, therefore, could represent a glycan context in which both selectin-binding epitopes are present on a single molecule, potentially altering adhesion properties compared with either epitope alone.

Detection and research approaches for sLeXsLeA rely on established glycan analysis methods. Monoclonal antibodies such as CSLEX-1 (primarily recognizing sLe^x) and HECA-452 (broadly reactive to sLe^x/sLe^a) are used in histology and flow assays, while mass spectrometry, high-performance liquid chromatography, and glycan arrays enable structural confirmation and quantification.

In research and clinical contexts, sLe^a's status as CA19-9 and sLe^x's role in metastasis make dual expression a topic of interest for understanding adhesion biology and developing diagnostic or therapeutic tools.