执业兽医资格考试免疫学主要组织相容性复合体精要.pptVIP

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * MHC对免疫应答的遗传调控 Example: If MHC X was the only type of MHC molecule Population threatened with extinction Survival of individual threatened Pathogen that evades MHC X MHC XX Example: If each individual could make two MHC molecules, MHC X and Y Impact on the individual depends upon genotype Pathogen that evades MHC X MHC XX MHC XY Population survives MHC YY but has sequences that bind to MHC Y Example: If each individual could make two MHC molecules, MHC X and Y……and the pathogen mutates Population threatened with extinction Survival of individual threatened Pathogen that evades MHC X but has sequences that bind to MHC Y MHC XX MHC XY MHC YY The number of types of MHC molecule can not be increased ad infinitum ….until it mutates to evade MHC Y YRYR XY XX XXR XYR YXR YYR YY XRXR XRYR From 2 MHC types and 2 variants……. 10 different genotypes Variants of each type of MHC molecule increase the resistance of the population from rapidly mutating or newly encountered pathogens without increasing the number of types of MHC molecule Variant MHC molecules protect the population Pathogen that evades MHC X and Y MHC XY MHC XX MHC YY MHC XXR MHC YYR …but binds to the variant MHC XR and MHC YR 第六节 HLA与医学 HLA在医学上的意义 HLA与器官移植 HLA与疾病的关联 HLA与法医学 一、HLA与器官移植 人体移植排斥反应中的主要靶抗原 MHC多态性导致供受者HLA型别的差异 移植前HLA配型 二、HLA与疾病的关联 关联 指某些特定HLA型别的个体易患某些疾病(正相关）或对某些疾病有较强的抵抗力（负相关） 关联程度 相对危险性（RR，relative risk） 三、HLA与法医学 个体识别 ？？？ 亲子鉴定 ？？？ 祝 大家考试顺利！ * * * * * * * * * * * * * * * * * * ?2 ?1 ?-chain of 29-32kDa ?-chain of 32-34kDa ?2 ?1 Overall structure of MHC class II molecules a and b chains anchored to the cell membrane ?2 ?2 domains have structural amino acid sequence homology with Ig C domains Ig GENE SUPERFAMILY Peptide antigen in a groove 肽结合区 免疫球蛋白样区 胞质区 跨膜区 MHC class II molecule structure Cleft is made of both a and b chains 肽结合区 α1、β1组成, 抗原肽结合槽 ?螺旋和β片层组成的槽状结构 两端开放,容纳10-30aa的抗原肽 多态性区 条状3D构象 球状3D构象 MHC class I M