Tissue-specific regulation of inflammation

Proteins of the complement system are important effectors and modulators of inflammation. The complement cascade is triggered by microbes, tissue debris, and specific antibodies. Serum complement proteins are derived primarily from liver, but extrahepatic complement synthesis is important in homeostasis and in local host defenses. Tissue-specific regulation of expression of complement genes is governed by mechanisms similar to those that regulate other “acute phase reactants.” That is, tissue injury or infection elicit changes in expression of these acute phase proteins, which, although variable in kinetics, magnitude, and direction, are a consequence of an elaborate system of cell-to-cell communication. This communication is mediated via a complex network of cytokines, including the interferons, interleukins, several growth factors, and sex hormones. The cell biological and molecular biological details of these mechanisms are now under active investigation. An understanding in molecular terms of the bala...