Sunyer J O, Boshra H, Li J
Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 413 Rosenthal, 3800 Spruce St., Philadelphia, PA 19104, USA.
Vet Immunol Immunopathol. 2005 Oct 18;108(1-2):77-89. doi: 10.1016/j.vetimm.2005.07.009.
Anaphylatoxins are small molecules ( approximately 9 kDa) that are generated as a result of the activation of the complement system. These molecules play an important role in inflammation, and they are responsible for the activation of various innate and adaptive immune processes. The study of these important inflammatory molecules has been restricted to mammalian species so far. Recent studies have shown that teleost fish, unlike any other known animal species, contain multiple forms of the C3a anaphylatoxin, all of which are functionally active and play a prominent role in inducing superoxide production in fish leukocytes. The C5a anaphylatoxin has also been characterized in these animals, and like in mammals, it plays an important role in leukocyte chemotaxis and in triggering the respiratory burst of leukocytes. Interestingly, it has been shown that rainbow trout anaphylatoxins play an unexpected role in enhancing phagocytosis of particles. C5a and C3a receptors have recently been cloned and characterized in rainbow trout, suggesting that the duplication of these receptors from a common ancestor occurred before the emergence of teleosts. The studies derived from these molecules in teleost fish indicate that the basic structure and function of anaphylatoxins and their receptors, have been conserved for more than 300 million years.
过敏毒素是小分子（约9 kDa），是补体系统激活的产物。这些分子在炎症中起重要作用，负责激活各种先天和适应性免疫过程。迄今为止，对这些重要炎症分子的研究仅限于哺乳动物物种。最近的研究表明，硬骨鱼与其他任何已知动物物种不同，含有多种形式的C3a过敏毒素，所有这些毒素都具有功能活性，并且在诱导鱼类白细胞产生超氧化物方面发挥着重要作用。C5a过敏毒素在这些动物中也有特征描述，并且与在哺乳动物中一样，它在白细胞趋化性以及触发白细胞呼吸爆发中起重要作用。有趣的是，已经表明虹鳟鱼过敏毒素在增强颗粒吞噬作用方面发挥了意想不到的作用。C5a和C3a受体最近已在虹鳟鱼中克隆和表征，这表明这些受体从共同祖先的复制发生在硬骨鱼出现之前。来自硬骨鱼中这些分子的研究表明，过敏毒素及其受体的基本结构和功能已经保守了超过3亿年。
