Complement (music)

Phenotype

Neuroscience

Biology

Gene

Complement system

Function (biology)

Classical complement pathway

Complement receptor

Complementation

Immunology

Immunity

Computational biology

Cell biology

Genetics

Homeostasis

Immune system

Nature Immunology

Nearly a century after the significance of the human complement system was recognized, we have come to realize that its functions extend far beyond the elimination of microbes. Complement acts as a rapid and efficient immune surveillance system that has distinct effects on healthy and altered host cells and foreign intruders. By eliminating cellular debris and infectious microbes, orchestrating immune responses and sending 'danger' signals, complement contributes substantially to homeostasis, but it can also take action against healthy cells if not properly controlled. This review describes our updated view of the function, structure and dynamics of the complement network, highlights its interconnection with immunity at large and with other endogenous pathways, and illustrates its multiple roles in homeostasis and disease.

Complement: a key system for immune surveillance and homeostasis