title: The "ins and outs" of complement-driven immune responses.
abstract: The complement system represents an evolutionary old and critical component of innate immunity where it forms the first line of defense against invading pathogens. Originally described as a heat-labile fraction of the serum responsible for the opsonization and subsequent lytic killing of bacteria, work over the last century firmly established complement as a key mediator of the general inflammatory response but also as an acknowledged vital bridge between innate and adaptive immunity. However, recent studies particularly spanning the last decade have provided new insights into the novel modes and locations of complement activation and highlighted unexpected additional biological functions for this ancient system, for example, in regulating basic processes of the cell. In this review, we will cover the current knowledge about complement's established and novel roles in innate and adaptive immunity with a focus on the functional differences between serum circulating and intracellularly active complement and will describe and discuss the newly discovered cross-talks of complement with other cell effector systems particularly during T-cell induction and contraction.
authors: Division of Transplant Immunology and Mucosal Biology, MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK.
authors: Simon
authors: S
authors: Freeley
authors: Division of Transplant Immunology and Mucosal Biology, MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK. claudia.kemper@kcl.ac.uk.|Laboratory of Molecular Immunology and the Immunology Center, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Bethesda, MD, USA. claudia.kemper@kcl.ac.uk.
authors: Claudia
authors: C
authors: Kemper
authors: Division of Transplant Immunology and Mucosal Biology, MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK.
authors: Gaëlle
authors: G
authors: Le Friec
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D005075:Biological Evolution; D001798:Blood Proteins / Q000276:immunology*; D003167:Complement Activation; D003165:Complement System Proteins / Q000276:immunology*; D006706:Homeostasis; D006801:Humans; D007113:Immunity, Innate; D007249:Inflammation / Q000276:immunology*; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D001798:Blood Proteins; D003165:Complement System Proteins
keywords: T cells; adaptive immunity; cell metabolism; complement; complosome; inflammasomes