Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
3358361 | Inmunología | 2007 | 12 Pages |
Abstract
Ficolins are oligomeric defence proteins assembled from collagen-like stalks and fibrinogen-like domains that are able to sense danger signals such as pathogen- or apoptotic cell-associated molecular patterns. In humans, L- and H-ficolins have been characterized in serum whereas M-ficolin is secreted by monocytic cells. Like mannan-binding lectin (MBL), they are able to associate with MBL-associated serine proteases and to trigger activation of the lectin pathway of complement, a major effector system of humoral innate immunity. They can also act as opsonins to enhance clearance of their targets by phagocytosis. Recent structural studies have shown that L-ficolin is a versatile recognition protein able to bind acetylated molecules and neutral carbohydrates through different binding sites, whereas H-ficolin has a single binding site with a more restricted specificity for neutral carbohydrates. Phylogenetic studies reveal that ficolins have been conserved through evolution, supporting the hypothesis that the primitive complement system was a lectin-based opsonic system, and emphasizing the essential role of carbohydrate recognition proteins in innate immunity.
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Immunology
Authors
N.M. Thielens, C. Gaboriaud, G.J. Arlaud,