...). The functions of the complement proteins of innate immunity are governed by the weak interactions between the activated proteins and their regulators. Complement is effective in attacking pathogens, but not the human host, and imbalances in this process can lead to disease conditions. The inherent complexity...

... emerged implicating molecules canonically involved in the immune system and inflammation accompanying neurodegeneration (e.g. classical complement cascade) as important players in the normal elimination of synapses in the developing nervous system. As a result, a question has emerged as to whether...

... on the endothelium, facilitating adhesion and migration of inflammatory cells into the subendothelial space. Another inflammatory process associated with postprandial lipaemia is the activation of the complement system. Its central component C3 has been associated with obesity, coronary sclerosis, the metabolic...

... with disease relevance are candidates for therapeutic intervention, namely caspase-mediated apoptosis, blood coagulation, the matrix metalloproteinase cascade and the complement cascade. Understanding the various steps involved in the functioning of a cascade is key to deciding possible points of intervention...

... through activation of the complement system via MBL-associated serine proteases (MASPs). This can cause the lysis of Gram-negative bacteria and also opsonize a wide spectrum of potential pathogens for phagocytosis. MBL may also influence phagocytosis in the absence of complement activation through...

...J.C. Jensenius; P.H. Jensen; K. McGuire; J.L. Larsen; S. Thiel Mannan-binding lectin (MBL) is a plasma protein involved in the innate immune response. It binds to a number of micro-organisms and promotes killing of these through complement activation either directly or through opsonization...

...-organisms) and mediate effector functions associated with killing/phagocytosis. MBL is the only collectin which activates complement. It resembles in quaternary structure the complement protein C1q, which recognizes targets via charge clusters. Binding of MBL to a surface activates MBL-associated serine...

...M. K. Pangburn; N. Rawal The multisubunit enzymes of the complement system that cleave C5 have many unusual properties, the most striking of which is that they acquire their specificity for C5 following cleavage of another substrate C3. C5 convertases are assemblies of two proteins C4b and C2a...

...E. McGreal; P. Gasque C1q is an essential component of the phylo-genetically ancient innate complement (C) system and is crucial to our natural ability to ward off infection and clear toxic cell debris (e.g. amyloid fibrils, apoptotic cells). Several candidate C1q receptors [C1q receptor...

...A. M. Blom C4b-binding protein (C4BP) is a potent inhibitor of the classical pathway of the complement system. This large plasma glycoprotein consists of seven identical α-chains and a unique β-chain held together by disulphide bridges. Both types of subunits are composed almost exclusively...

...C. L. Harris; D. A. Fraser; B. P. Morgan Complement is a core component of the immune system, which performs vital roles in immune surveillance. However, the active products that enable complement to perform its physiological roles can inappropriately target self tissues and cause pathology...

...A. Herbert; J. O'Leary; M. Krych-Goldberg; J. P. Atkinson; P. N. Barlow Members of the regulator of complement activation (RCA) protein family perform a vital role in health and disease. In this report we describe our efforts to solve the structures of human membrane cofactor protein (CD46...

...G. J. Arlaud; C. Gaboriaud; N. M. Thielens; V. Rossi The classical complement pathway is a major element of innate immunity against infection, and is also involved in immune tolerance, graft rejection and various pathologies. This pathway is triggered by C1, a multimolecular protease formed from...

...-cell pool. In addition, B-cell responses are influenced by signals transduced through a CD19-CD21 cell surface receptor complex, where the binding of complement C3d to CD21 links humoral immune responses with the innate immune system. This review outlines recent biochemical and genetic studies...