MECA-79/Peripheral Node Addressin [MECA-79]

MECA-79 recognizes a carbohydrate epitope that is found on a family of sialomucins known as peripheral node addressins or PNAds that serve as ligands for CD62L. This set antigens has been referred to as peripheral node addressin (PNAd) with the molecular mass 50-250 kD. It has been identified that GlcNAc-6-SO4 sulfation contributes to MECA-79 binding and the core 1 beta1,3-N-acetylglucosaminyltransferase is required for the generation of the MECA-79 epitope. MECA-79 is expressed on high endothelial venules (HEV) of lymphoid tissues, chronic inflamed tissues and rheumatoid synovia. The interaction of PNAd with CD62L receptor is involved in tethering and rolling of lymphocytes along HEV in lymphoid tissues. The initiation of homing and rolling is critical for the localization of lymphocytes to peripheral lymph nodes, an event that is necessary for the cellular response to inflammation.