Evolution of the lectin-complement pathway and its role in innate immunity.
Discrimination between self and non-self by lectins (carbohydrate-binding proteins) is a strategy of innate immunity that is found in both vertebrates and invertebrates. In vertebrates, immune recognition mediated by ficolins (lectins that consist of a fibrinogen-like and a collagen-like domain), as well as by mannose-binding lectins, triggers the activation of the complement system, which results in the activation of novel serine proteases. The presence of a similar lectin-based complement system in ascidians, our closest invertebrate relatives, indicates that the complement system probably had a pivotal role in innate immunity before the evolution of an adaptive immune system in jawed vertebrates.
Fujita
Teizo
T
Department of Biochemistry, Fukushima Medical University School of Medicine, Japan. tfujita@fmu.ac.jp
D000818:Animals; D005075:Biological Evolution; D003167:Complement Activation; D019143:Evolution, Molecular; D006801:Humans; D037102:Lectins / Q000737:chemistry / Q000502:physiology*; D050606:Mannose-Binding Protein-Associated Serine Proteases; D018448:Models, Immunological; D012697:Serine Endopeptidases / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction; D014561:Urochordata / Q000276:immunology
D037102:Lectins; D050606:Mannose-Binding Protein-Associated Serine Proteases; D012697:Serine Endopeptidases