LAUSR

Immunology. The complement system is one of the main pillars of innate mmunity and detailed studies over past decades have established n core the basic mechanisms of complement activation and it’s egulation. Subsequent establishment of a significant number of iagnostic assays allowed further definition of the role that comlement plays under normal and disease conditions such as in any immunologically-mediated diseases and infections. In addiion, establishment of experimental animals with specific deletions nd mutations of complement provided further support for the cruial role of complement in homeostasis and disease and the need or attenuation of complement activation processes in vivo so as to everse complement-mediated injury. Thus, complement found its olid place in textbooks and in the minds of researchers and cliniians as the prime protector against invading pathogens but also as ey contributor to the inflammatory diseases when dysregulated – nd was considered in essence explored and understood for many ears. However, recent exciting developments in the field suggest hat this ancient system has much more ‘in store’ than previusly thought: surprisingly, complement activation is not confined o the extracellular space but also occurs within cells where t contributes to the direct regulation of key cellular processes. hus, in this special issue of Molecular Immunology we bring ogether further topical insights that have been achieved recently n a number of basic processes driven by complement activity uch as: impact on cell metabolism and survival, the contribution f complement to self-derived danger sensing within cells such s cholesterol crystals and subsequent cytokine response during