Molecular Regulation of Complement Gene Expression
The complement system consists of a group of more than 20 proteins that initiate and amplify antimicrobial host defense mechanisms mediated by the inflammatory response. The early acting proteins of the complement cascade and several proteins that function in control of complement activation are synthesized in hepatocytes and in extrahepatic tissues in mononuclear phagocytes. Differential regulation of complement production at hepatic and extrahepatic sites permits independent control of the size of the complement reservoir in plasma and the local concentration of these proteins at local tissue sites of inflammation. The effect of this selective control is illustrated in recent studies of endotoxin, interleukin-l, tumor necrosis factor and IFN-gamma modulation of complement gene expression. The mechanisms involved in cytokine regulation of these genes are relevant to the molecular iinnunobiology of specific immune responses, as well as to the regulation of inflammation. Many of these studies are reviewed in the references.
- Ramadori JG, Sipe JD, Colten HR. Expression and regulation of the murine serum amyloid A (SAA) gene in extrahepatic sites. J Iir¢nunol 1985; 135: 3645–3647.Google Scholar
- Ramadori G, Sipe JD, Dinarello CA, Mizel SB, Colten HR. Pretranslational modulation of acute phase hepatic protein synthesis by murine recombinant interleukin 1 (IL-1) and purified human IL-1. J Exp Ned 1985; 162: 930–942.Google Scholar