Scheme of the complement system. The complement system, also known as complement cascade, is a part of the humoral, innate immune system and enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and attack the pathogen's cell membrane. [1]

The complement system refers to a series of >20 proteins, circulating in the blood and tissue fluids. Most of the proteins are normally inactive, but in response to the recognition of molecular components of microorganisms they become sequentially activated in an enzyme cascade – the activation of one protein enzymatically cleaves and ...

Feb 14, 2023 · Like the components of the blood clotting system, complement proteins interact with one another in a catalytic cascade known as complement cascade. The complement system is made up of approximately 40 proteins of an enzymatic, receptor, and regulatory nature, which all participate in a very well-functioning immune system.

Sep 5, 2023 · Complement activation proceeds through a finely regulated cascade of proteolytic reactions that initially engages soluble pattern-recognition molecules and leads to the assembly of multiprotein...

Feb 2, 2012 · Complement mediates responses to inflammatory triggers through a co-ordinated sequential enzyme cascade leading to clearance of foreign cells through pathogen recognition, opsonisation and lysis . Complement also possesses anti-inflammatory functions: it binds to immune complexes and apoptotic cells, and assists in their removal from the ...

Acting as a cascade of enzymatic reactions, complement is activated through the classical (CP), the alternative (AP) and the lectin pathway (LP) based on the recognized molecules.

The complement cascade is initiated either via the fluid-phase formation of C3(H2O) (alternative pathway; AP) or through pattern recognition on a surface by either lectins (mannan-binding...

The interactions along the complement cascade can occur synchronously or asynchronously on cell surfaces and even within the cell. The interactive diagram below simplifies the cascade of interactions along three converging linear paths—the classical, lectin, and alternative pathways—for presentation purposes. 1,3,4

The complement cascade is a network of plasma proteins and cell surface receptors that recognize non-self-components and triggers one of the three pathways. An antigen–antibody complex triggers the classical pathway; carbohydrates trigger the lectin pathway; and foreign surfaces trigger the alternative pathway.

Schematic overview of the complement cascade, illustrating the three activation pathways (classical, lectin, and alternative) with the C3 convertase complexes of the classical, lectin, and the...