Activation of the lectin complement pathway by ficolins

Mannose-binding lectin (MBL), a serum lectin specific for mannose or N-acetylglucosamine (GlcNAc), which contains both a collagen-like domain and a carbohydrate-recognition domain (CRD). plays a role in innate immunity by acting as an opsonin and activating complement in association with MEL-associated serine protease (MASP) via the lectin pathway. Another type of GlcNAc-binding lectins termed "ficolins" exist in serum. They are characterized by the presence of both a collagen-like domain and a fibrinogen-like domain. Investigations of two types Of human serum ficolins, ficolin/P35 and Hakata antigen, revealed that they are associated with MASPs and sMAP, a truncated protein of MASP-2, and activate complement. These findings indicate that, like MEL. serum ficolins an collagenous lectins capable of activating the lectin pathway and thus have a role in innate immunity. (C) 2001 Elsevier Science B.V. All rights reserved.