上海交通大学精品课程《医学免疫学》课件PPT补体系统.ppt

第四讲 补 体 系 统 （complement system) Components of the Classical Pathway Classical Pathway Generation of C3-convertase Classical Pathway Generation of C3-convertase Classical Pathway Generation of C5-convertase Components of mannose-binding lectin pathway Mannose-binding lectin pathway Components of thealternative pathway Spontaneous C3 activation C3-activationthe amplification loop C3-activationthe amplification loop C3-activationthe amplification loop C3-activationthe amplification loop C3-activationthe amplification loop C3-activationthe amplification loop C3b stabilization andC5 activation 替代途径激活特点 体内C3自发水解成C3b，使替代途径处于准激活状态 替代途径能识别自己与非己 替代途径是补体系统重要放大机制 C5- convertase of the three pathways Components of the Terminal sequence Terminal sequence C5-activation Terminal sequence assembly of the lytic complex Terminal sequence :insertion of lytic complex into cell membrane Pathways of complement activation 三条激活途径的主要不同点 补体激活过程中的调控蛋白 C1qrs breakdown C1-inhibitor deficiency:angioedema C3b regulation on self and activator surfaces Control of spontaneousC3 activation via DAF 超急排斥（HAR, hyper acute rejection） 移植受者 (人) 血流中的异种反应天然抗体 (XNA) 识别供者 (猪) 器官血管内皮细胞膜上以半乳糖苷为抗原表位的糖蛋白，激活补体级联反应，引起内皮细胞裂解和激活，导致凝血和血管阻塞，移植物坏死。 排斥时间：40～120分钟。 现有的主要对策 1、去除或抑制人体内的异种反应天然抗体XNA； 2、应用转基因技术，抑制补体活性。如获 得带有人衰变加速因子(DAF) 基因的转 基因猪。 3、敲除猪的半乳糖基转移酶基因。 Biological effects of C5a C3b Bb C3b C5-convertase of the Alternative Pathway C4b C2b C3b C5-convertase of the Classical and lectin Pathways Generation of C5 convertase leads to the formation of the membrane attack complex Terminal sequence C6 C 9 C8 C7 C5 C3b C2 b C4b C5 b C5a C5 b C6 C7 C5 b C6 C7 C8 C 9 C 9 C 9 C 9 C 9 C 9 C 9 C 9 C 9 complement Kill the Parasite MACs effect CLASSICAL PATHWAY ALTERNATINE PATHWAY antibody dependent Mannose binding lectin dependent Activation of C3 and generation of C5 conv