• Cytokines secreted by phagocytes in response to infection include:
– IL-1
• activates vascular endothelium and lymphocytes • Increases adhesiveness of leukocytes
INNATE IMMUNITY
ADAPTIVE IMMUNITY
INNATE IMMUNE SYSTEM 固有免疫系统
INNATE IMMUNE SYSTEM
• Anatomic Factors • Mechanical Factors • Biochemical Factors
组织屏障及其作用
5 Mast cells
Capable of phagocytosis Process and present antigen using MHC class I or II receptors LPS can directly induce release of mast cell mediators Complement (C3a and C5a) induce mast cells to release
3.分泌
酶
溶菌酶 酸性水解酶 赖氨酸酶 酯酶 阳离子蛋白 弹性纤维蛋白酶
4.杀伤 肿瘤细胞
其它因子 前列腺素 白三烯 补体成分 血小板活化因子 结合蛋白 凝血因子
Immune Cells and Innate Immunity (cont’d)
3 g/d T cells
– Two types of T cell receptors • One composed of and chains (basic T cell antigen receptor) • One composed of g and d chains (minor population of T cells)
mediatorsChemotaxis, complement activation, inflammation
TNF-a secreted by mast cells results in neutrophil influx into
infected site
mIgM
CD5+
细菌表面共有的TI-2型多糖抗原，如肺炎球菌荚膜多糖
carbohydrates)
• Host cells have complement regulatory proteins on their surface that protect them from spontaneous activation of C3 molecules
（二）Cytokines in Innate Immunity
抗感染免疫课件
细胞因子
补体 免疫球蛋白
粒细胞
B细胞
单核细胞
浆细胞 T细胞
巨噬细胞
１９８０年，世界卫生组织宣布天花彻底消灭
免疫系统解剖
免疫系统的两道防线
• 固有免疫（Innate Immunity） 机体天然存在直接抵抗外来侵袭的免疫 系统
• 获得性免疫（Adaptive Immunity） 机体特异性识别和排除抗原的免疫系统， 具有记忆性的特点
（一）皮肤粘膜及其附属成分的屏障作用 1 物理屏障 2 化学屏障 分泌液中的各种杀菌物质 3 微生物屏障 正常菌群
（二）血脑屏障 （三）血胎屏障 （四）血睾屏障
（一）Complement System
• Three pathways now known
– Classical – Alternative – Lectin or MBL pathway (binding to mannose-containing
TCRγδ
heat-shock protein （ HSP ）
脂类抗原
Target cell
病毒蛋白 分枝杆菌非肽分子
Immune Cells and Innate Immunity (cont’d)
4 B-1 cells (minor fraction of B cells, do not require T-cell help) CD5+mIgM+Bcells, produce IgM antibody
– IL-12
• Activates NK cells and induces Th1-cell differentiation
– IL-18 – IFN , – TNF-
• Activates vascular endothelium and increases vascular permeability, leading to accumulation of Ig and complement in infected tissues
– Have two major functions • Lysis of target cells • Production of cytokines (IFN-g and TNF-)
吞噬细胞的功能
1 抗原 呈递作用
2 吞噬并杀伤 病原微生物
细胞因子
IL-1 IL-6 IL-12 TNF- IL-8 GM-CSF MCP1
免疫细胞及其作用
• 1 Phagocytes
– Neutrophils – Moncyte/macrophaห้องสมุดไป่ตู้e
– Eosinophils (to a lesser extent) • 2 NK cells (large granular lymphocytes)
– Antibody-dependent cell-mediated cytotoxicity (ADCC)
– IL-6
• Induces B-cell terminal maturation into Ig-producing plasma cells
– IL-8
• Induces expression of 2 integrin adhesion molecules on neutrophils, leading to neutrophil migration to infection site