Sialyl Lewis A (sLeA) (sLeA)

Sialyl Lewis A (sLeA), also known as CA19-9, is a tetrasaccharide carbohydrate antigen that serves as a primary ligand for E-selectin, a cell adhesion molecule found on vascular endothelial cells (nih.gov). It is synthesized through the sequential action of sialyltransferases and fucosyltransferases on lactosamine precursors (frontiersin.org). In oncology, sLeA is a well-characterized tumor-associated carbohydrate antigen (TACA) overexpressed in pancreatic, colorectal, and gastric cancers, where it facilitates metastasis by enabling tumor cells to adhere to the endothelium (researchgate.net). In the context of adoptive cell therapy, sLeA and its sialylated precursors on the surface of therapeutic immune cells (such as T cells, Tregs, and MSCs) are targets for glycoengineering to improve homing and tissue infiltration (oup.com). By enzymatically enforcing the expression of sLeA or its isomer sLeX, therapeutic cells can more effectively tether and roll on the endothelium of target tissues, such as the bone marrow or inflamed brain regions, thereby enhancing therapeutic efficacy (nih.gov). The target also encompasses related glycan precursors, such as sialylated type 1 and type 2 lactosamines, which are the essential substrates for the final fucosylation step in the biosynthesis of functional selectin ligands (frontiersin.org).

Other names

CA19-9Carbohydrate antigen 19-9Sialylated Lewis ASialyl-Le(a)Sialylated type 1 lactosamine (precursor)Sialylated type 2 lactosamine (precursor)Selectin ligand

Enhancement of cell homing via E-selectin binding, Antibody-dependent cellular cytotoxicity (ADCC), Complement-dependent cytotoxicity (CDC), Inhibition of tumor cell adhesion and metastasis.