Fujita Teizo
Department of Biochemistry, Fukushima Medical University School of Medicine, Japan.
Nat Rev Immunol. 2002 May;2(5):346-53. doi: 10.1038/nri800.
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.
凝集素（碳水化合物结合蛋白）对自身与非自身的区分是一种先天免疫策略，在脊椎动物和无脊椎动物中均有发现。在脊椎动物中，由纤维胶凝蛋白（由纤维蛋白原样和胶原原样结构域组成的凝集素）以及甘露糖结合凝集素介导的免疫识别会触发补体系统的激活，进而导致新型丝氨酸蛋白酶的激活。在与我们亲缘关系最近的无脊椎动物海鞘中存在类似的基于凝集素的补体系统，这表明补体系统可能在有颌脊椎动物适应性免疫系统进化之前的先天免疫中起关键作用。
