chapter 3 Antigen.ppt

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1、Chapter3Antigen,Ag第三章抗原Thehumanbodyisan"orderlycellssociety",allkindsofcellsintheimmunesurveillanceinanorderlywayunderthedivision.Theimmunecellsisthe"hero"ofmaintainsocialstability.Whentheimmunecellsbyantigenstimulationforeignpathogensandtumorcells,canproducetheimmuneresp

2、onse.Antigenisfuseofimmuneresponse人体是一个有序的“细胞社会”，各种细胞在免疫细胞监视下有条不紊的分裂繁殖。细胞社会一切井然有序。可以说免疫细胞是维护细胞社会稳定的“功臣”。当免疫细胞遇到抗原异物（病原体、肿瘤细胞）刺激时，可发挥免疫应答。抗原是免疫反应的“导火线”1.Conceptionofantigen，Ag概念Anantigenisasubstancethatinducestheformationofimmuneresponse.(bindingTCR/BCR,inducingformationof

3、antibodyoreffectTcell,combiningwithantibodyoreffectTcellarecalledantigen).抗原是指能引起免疫反应的物质。即：能与TCRBCR受体结合，既能刺激机体产生抗体或效应T细胞，并能与相应抗体及效应T细胞结合的物质如细菌、病毒、肿瘤细胞物质→免疫系统↗抗体------免疫原性↘↘效应T〉完全抗原↘特异结合↙-------免疫反应性--半抗原抗原的基本特性AbilityofinducingformationofantibodyoreffectTcelliscalledImmun

4、ogenicity（免疫原性）AbilityofbindingantibodyoreffectTcelliscalledImmunoreactivity（免疫反应性）immunogenicity+Immunoreactivity--CompleteAntigen（完全抗原）forexample,microbialpathogens,tumor2.Thebasiccharacteristicoftheantigen免疫原性免疫反应性Immunoreactivity---IncompleteAntigenorHapten（半抗原）Hapten

5、sarelow-molecular-weightcompoundsthatarenotimmunogenicbutItbecomeimmunogeniciftheyareconjugatedtohigh-molecular-weightcarriers（载体）如青霉素、链霉素.Hapten+carriers---completeantigenHapten-carrierconjug§1Moleculebasisofantigenspecific第一节决定抗原特异性的分子结构基础SpecificityAgepitope特异性---Ag表位A

6、gspecificityisdeterminantedbyAgepitope一.Conceptionofantigenicepitope表位概念AnepitopeorantigenicdeterminantisThespecificChemicalgroupsthataparticularantibodyorBCR/TCRbindsinantigenmolecule.抗原物质中决定抗原特异性的特殊化学集团称为抗原表位/抗原决定簇Everyimmunogenmustcontainoneormoreepitopesthatenableitto

7、serveasanantigenConstitutionofepitope:表位的结构Everyepitopeiscomposedby5～15aminoacidresidues,5-7oligosaccharidesornucleicacidresidues二、classificationofantigenicepitopes表位类型Sequentialepitope---linear线性表位Conformationalepitope---non-linear非线性表位T-epitope:bindbyTCRB-epitope:bindby

8、BCRT表位—CD4TCD8T表位三、epitope-carriereffect半抗原-载体效应haptenepitope---B，carrierepitope---TH四、commonant