C-Reactive Protein (CRP)

C-reactive protein (CRP) is an acute-phase protein derived from the liver, whose level rises in response to inflammation. It belongs to the pentraxin family of proteins and this gene encodes a polypeptide with 224 amino acids. CRP is elevated following macrophages and T cells secrete interleukin-6. CRP binds to lysophosphatidylcholine, which is expressed on the surface of dead or dying cells (and some types of bacteria), activating the complement system through C1q to exert its physiological functions. For example, when it binds to phosphorylcholine expressed on the surface of bacterial cells such as pneumococci, the complement system was activated and the phagocytosis of macrophages is promoted resulting in clearing necrotic and apoptotic cells and bacteria. By binding to ischemic or hypoxic cells take advantage of this mechanism, CRP also promotes cell regeneration over a longer period of time. But they are eliminated prematurely due to the binding of CRP.