Human Natural Killer-1 carbohydrate epitope (HNK-1)

The Human Natural Killer-1 (HNK-1) carbohydrate epitope is a unique sulfated trisaccharide (HSO3-3GlcAβ1-3Galβ1-4GlcNAc) primarily expressed on various cell adhesion molecules, such as NCAM and L1, and extracellular matrix proteins in the nervous system (Schachner & Martini, 1995). It plays a critical role in mediating cell-cell and cell-matrix interactions, facilitating processes such as neurite outgrowth, synaptic plasticity, and cell migration during development and in the adult brain (Morita et al., 2008). In clinical pathology, HNK-1 is a major target for autoantibodies in IgM paraproteinemic peripheral neuropathies, specifically anti-myelin-associated glycoprotein (MAG) neuropathy, where the antibodies bind to the HNK-1 epitope on MAG and other glycolipids, leading to demyelination (Nobile-Orazio, 2004). Additionally, HNK-1 (also known as CD57) serves as a marker for mature natural killer cells and specific subsets of T-cells, and its expression is altered in various cancers and neurodegenerative conditions like Alzheimer's disease (Nielsen et al., 2013). Therapeutic strategies involving HNK-1 often focus on managing autoimmune responses against it or exploring its potential in promoting neural repair.

Other names

CD57LEU-7L2 epitope3-O-sulfated glucuronyl-lactosamineHNK1

Modulation of cell-cell and cell-matrix interactions; target of autoimmune antibody-mediated demyelination in peripheral nerves.