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Complement — tapping into new sites and effector systems

Abstract

Complement is traditionally known to be a system of serum proteins that provide protection against pathogens through direct cell lysis and the mobilization of innate and adaptive immunity. However, recent work indicates that the complement system has additional physiological roles beyond those in host defence. In this Opinion article, we describe the new modes and locations of complement activation that enable it to interact with other cell effector systems, such as growth factor receptors, inflammasomes and metabolic pathways. We propose that the location of complement activation dictates its function.

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Figure 1: Distinct location-directed functions of complement activation.
Figure 2: Functional crosstalk between complement and other cell effector systems.
Figure 3: Complement at the nexus of the extensive crosstalk between cell effector systems.

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Acknowledgements

The authors acknowledge their funding sources: the Medical Research Council, The European Union and The Wellcome Trust. Their research was also funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London, UK. The views expressed are those of the authors and not necessarily those of the National Health Service, the NIHR or the Department of Health. The authors also acknowledge and thank P. Garred (University of Copenhagen, Denmark). The authors apologize to the groups whose work they were unable to cite owing to space constraints.

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Correspondence to Claudia Kemper.

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Kolev, M., Friec, G. & Kemper, C. Complement — tapping into new sites and effector systems. Nat Rev Immunol 14, 811–820 (2014). https://doi.org/10.1038/nri3761

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