[生物学]浙江大学医学免疫学经典课件04-Antibody.ppt

* * * * * * * * 每个结构域由110个AA 酸构成， 几股肽链折叠而成的两个反向平行的B 片层折叠。两个B 片层之间由一个链内二流键垂直连接。 形成三明治的结构 * * 每个结构域由110个AA 酸构成， 几股肽链折叠而成的两个反向平行的B 片层折叠。两个B 片层之间由一个链内二流键垂直连接。 形成三明治的结构 * * CDR (complementarity-determining region) Because these sequences form a surface that is complementary to the three-dimensional structure of the bound antigen, the HVR also called CDR * * * * * * * 每个结构域由110个AA 酸构成， 几股肽链折叠而成的两个反向平行的B 片层折叠。两个B 片层之间由一个链内二流键垂直连接。 形成三明治的结构 * * * * * 比如白喉抗毒素， 破伤风抗毒素 胃蛋白酶消化后提纯，去掉FC 段而降低发生超敏反应 * * * * * * * * * * * * * Allotype immunoglobulin This refers to genetic variation between individuals within a species. CH和CL上的一个或数个氨基酸残基的差异--- 遗传标志 Gm1-30 Idiotype (Id) immunoglobulin Variation in the V domain ,particularly in CDR, produces idiotype. Functions of V regions Recognition and binding to antigen - HVR (CDR) - neutralization of toxins (e.g. diphtheria, tetanus); - immobilization of microorganisms; - neutralization of viral activity Antibody: monomer(IgG,IgE)---2价 dimer(sIgA) --- 4价 Petamer(IgM) --- 5价 immunoglobulin Neutralization Bacterial toxins Host cell Toxin receptors Neutralization by antibody Phagocytosis of antibody-antigen complex by macrophage Fc receptor Forming phagosome neutralization of viral activity Function of C regions (Fc portion) 1. Activation of complement: IgM, IgG Ab( IgM、IgG )+Ag--- C1q----补体经典途径 IgG4、IgA和IgE的凝聚物----补体旁路途径 2. Binding to Fc receptor of cells Opsonization: enhancement of Ag uptake by macrophages (M?) Antibody-dependent cell-mediated cytotoxicity (ADCC): NK cells. Participation in type I hypersensitivity: IgE 3. Passage through the placenta (IgG, CH2) and mucosa (sIgA) immunoglobulin immunoglobulin Opsonization of antibody immunoglobulin Antibody-dependent cell-mediated cytotoxicity (ADCC) passage through the placenta(IgG) and mucosal(SIgA) Passage through mucosal(SIgA) Function of immunoglobulins immunoglobulin C