Afshar-Kharghan Vahid
J Clin Invest. 2017 Mar 1;127(3):780-789. doi: 10.1172/JCI90962.
In addition to being a component of innate immunity and an ancient defense mechanism against invading pathogens, complement activation also participates in the adaptive immune response, inflammation, hemostasis, embryogenesis, and organ repair and development. Activation of the complement system via classical, lectin, or alternative pathways generates anaphylatoxins (C3a and C5a) and membrane attack complex (C5b-9) and opsonizes targeted cells. Complement activation end products and their receptors mediate cell-cell interactions that regulate several biological functions in the extravascular tissue. Signaling of anaphylatoxin receptors or assembly of membrane attack complex promotes cell dedifferentiation, proliferation, and migration in addition to reducing apoptosis. As a result, complement activation in the tumor microenvironment enhances tumor growth and increases metastasis. In this Review, I discuss immune and nonimmune functions of complement proteins and the tumor-promoting effect of complement activation.
补体激活除了作为固有免疫的一个组成部分以及对抗入侵病原体的一种古老防御机制外，还参与适应性免疫反应、炎症、止血、胚胎发生以及器官修复与发育。通过经典途径、凝集素途径或替代途径激活补体系统会产生过敏毒素（C3a和C5a）和膜攻击复合物（C5b-9），并调理靶细胞。补体激活终产物及其受体介导细胞间相互作用，从而调节血管外组织中的多种生物学功能。过敏毒素受体的信号传导或膜攻击复合物的组装除了减少细胞凋亡外，还促进细胞去分化、增殖和迁移。因此，肿瘤微环境中的补体激活会促进肿瘤生长并增加转移。在本综述中，我将讨论补体蛋白的免疫和非免疫功能以及补体激活的促肿瘤作用。
