《抗原呈递细胞》PPT课件.ppt

Chapter7APC Antigenpresentingcell APC DefinitionAPCisacellthatdisplayspeptidefragmentofproteinantigens inassociationwithMHCmolecules onitssurfaceandactivatesantigen specificTcells Inadditiontodisplayingpeptide MHCcomplexes APCsmustalsoexpresscostimulatorymoleculestoactivateTlymphocytesoptimally Tcellsdonotrecognisenativeantigens Y Y Y Y Y Y 活化增殖 产生抗体 无增殖无CK产生 BCR交联 AntigensmustbeprocessedinordertoberecognisedbyTcells Tcellresponse 无应答 无应答 无应答 无应答 抗原加工 递呈 第一节抗原提呈细胞的种类ProfessionalsAPC DendriticcellsMacrophagesBcells Non professionalAPC 在某些活性分子刺激下能被诱导表达MHC II类分子并能处理和提呈抗原的细胞 包括 内皮细胞 纤维母细胞 上皮及间皮细胞 嗜酸性粒细胞等 抗原提呈能力弱 广义APC 指能加工处理抗原并以抗原肽 MHC分子复合物的形式提呈抗原信息的所有细胞 Classificationanddistribution DCinlymphoidtissue InterdugutatingDC 分布于淋巴组织胸腺依赖区和次级淋巴组织FolliculusDC 分布于外周淋巴器官淋巴滤泡生发中心边缘区DC DCinnonlymphoidtissueInterstitialDC 分布于实质器官间质毛细血管附近郎格汉斯细胞 位于表皮和胃肠上皮部位 DCinbodyfluid输入淋巴液中的DC及外周血中的DC DendriticcellOrigin distributionandmigration 2 SurfacemoleculesImmatureDCaredifferentfrommatureDCinphenotype DCcharacteristics MorphologyExpressinghighlevelofMHCIImoleculeandotherco stimulatingmolecules ExtravasatetootherlymphoorganInitiateactivationofna veTcell DCsurfacemarkers 髓系DC 以CD11 CD11 CD13 CD 为标志人淋巴样DC CD11c CD123 BDCA2 CD45RA CD4 人DC主要特征性表面标志 CD1 CD11 CD83小鼠DC特异性标志 D1 NLDC145 FunctionsofDC1 InterfaceofinnateandadaptiveimmunityImmatureDC UnspecificantigenuptakePhagocytosisonthebasisofrecognitionMacropinocytosisMatureDC Antigenprocessingandpresentation 2 Involvedinimmunetoleranceandimmunememory 3 Cytokinesecretion Monocytes 组成 骨髓内的前单核细胞外周血中的单核细胞组织内的巨噬细胞功能 吞噬杀伤病原微生物抗原提呈调节免疫应答参与炎症 组织修复及组织再生 Bcell 抗原提呈 通过BCR特异性识别 结合并内化抗原 在低浓度可溶性抗原的提呈中起重要作用参与体液免疫应答 第二节抗原的处理与提呈 Antigenprocessingandpresenting DegradationofantigensbyoneoftwopathwaysyieldingantigenicpeptidesthataredisplayedboundtoMHCmoleculesonthesurfaceofantigen presentingcells Differentantigen processingandpresentationpathwaysEndogenousantigens thosegeneratedwithinthecell areprocessedinthecytosolicpathwayandpresentedonthemembranewithclassIMHCmolecules exogenousantigens thosetakenupbyendocytosis areprocessedintheendocyticpathwayandpresentedonthemembranewithclassIIMHCmolecules ThecytosolicpathwayPeptidesforpresentationaregeneratedbyproteasecomplexescalledproteasomesinthecytosolTAP transporterassociatedwithantigenprocessing mediatestranportationofpeptidesgeneratedinthecytosolintotheRERPeptidesassemblewithclassIMHCwithinRERClassImoleculesloadedwithpeptideexitfromtheRER andproceedtothecellsurfaceviatheGolgicomplex 内源性抗原加工 处理及提呈 TheendocyticpathwayPeptidesaregeneratedfrominternalizedmoleculesinendocyticvesiclesInRER classIIMHCmoleculesareassembledwiththeinvariantchain Li whichguidesthetransportationofclassIIMHCmoleculestoendocyticvesiclesPeptidesassemblewithclassIIMHCmoleculesbydisplacinglichainOnceapeptidehasbound thepeptide classIIcomplexistransportedtotheplasmamembrane 外源性抗原加工 处理及提呈 Cross presentationofexogenousantigensIncertaincases APCsmaypresentexogenousantigentocytotoxicTcellsinthecontextofclassIMHCmolecules PresentationofnonpeptideantigensThenonpreteinantigensarepresentedbymembersofthe