免疫细胞和免疫应答

ImmunocytesInstituteofImmunologyMedicalSchoolofZhejiangUniversityJianzhongChen(陈建忠office)chenjianzhong@1.Cellsofimmunesystem2.Tlymphocytes3.ⅠDevelopmentofTcells4.StagesofTcellmaturation5.PositiveandnegativeselectionPositiveselection〔阳性选择〕DPcellsthatbind,withmoderateaffinity,toMHC-Agonthymicstromacellssurvive----MHCrestriction〔MHC限制性〕MHCI----CD8+TcellsMHCII----CD4+TcellsNegativeselection〔阴性选择〕CellsthatbindtoMHC-Agonthymicstromacells(orauto-reactiveTcells,ART)willundergoapoptosisFormationofcentralimmunetolerance〔免疫耐受〕6.7.Tcellsurfacemarkers

8.TCR-CD3complexTCRAheterodimercomprisinganandachainoraandachainjoinedbyadisulfidebond.Function:specificrecognitionofpeptide-MHCcomplex.9.TCR-CD3complex10.Consistsof5proteinsthataredesignatedas

,

,

,and

.Threedimers:

,

,

()ThecytoplasmicdomaincontainsITAM(immunoreceptortyrosine-basedactivationmotif)YXXL/VFunction:transductionofsignalsthatleadtoTcellactivation.CD311.

Mainco-stimulatorymoleculesmediatinginteractionsbetweenTcellsandAPCs12.Receptorsofmitogens(丝裂原受体)PHA-RConA-RPWM-RCytokinereceptor(细胞因子受体)Virusreceptor(病毒受体)13.Leukocytedifferentiationantigen(LDA，白细胞分化抗原):Thecellsurfacemarkerswhichexpressordisappearonthedifferentleukocytesinthedifferentstageofdifferentiationandactivation.14.TCellSurfaceMoleculesCD(clusterofdifferentiation，分化群):Cellsurfacemoleculesofleucocytesthataredistinguishablewithmonoclonalantibodiesasanimmunologicmarker.CD1-35015.CD4andCD8(coreceptor)Function:1)HelptheinteractionbetweenTcellandAPCandenhancetherecognitionofantigenbyTCR;2)helptheTCR-CD3signalstransductionCD4:MHCIIAgbinding,ReceptorofHIVgp120CD8:MHCIAgbinding16.Co-stimulatorymoleculesCD28:itsligandsareB7familymolecules,includingB7-1/2(CD80/CD86)

Function:costimulation,activationofTcellsCTLA-4(CD152):homodimer,homologoustoCD28.

Function:inhibitsTcellcostimulation(thecytoplasmicdomaincontainsITIM)

17.©2005Elsevier18.Celladhesionmolecules

(细胞粘附分子)CAM:Agroupofproteinsinvolvedinadhesionofcelltocellorcelltoextra-cellularmatrix(ECM),suchasICAM-1,ICAM-2,ICAM-3,VCAM-1andPECAMetc.19.CategoriesofCAM1.Integrinfamily〔整合素家族〕2.Selectinfamily〔选择素家族〕3.Cadherin〔钙粘素家族〕4.IGSF(Igsuperfamily)〔免疫球蛋白超家族〕5.Mucin-likefamily〔黏蛋白样家族〕6.Others:PNAd,CD44,CD36

20.III.Tcellsubsets1．TCRTcellsandTCRTcells2．CD4+TandCD8+Tcells3．Th,TcandTreg4.NaiveTcells〔初始型〕,effectorTcells〔效应性〕andmemoryTcells〔记忆性〕21.22.IV.FunctionsofTcells1.CD4+helperTcells(Th)Th0:Thcellsthatsecretebroadspectrumofcytokinesatlowlevel.Th1:produceIL-2andIFN-

,butnotIL-4.Theyarechieflyresponsibleforcell-mediatedimmuneresponses,butcanalsohelpBcellstoproduceIgG2a,butnotmuchIgG1orIgE;Th2:secreteIL-4,5,10,13,butnotIL-2andIFN-

,areveryefficienthelpercellsforproductionofantibody,especiallyofIgG1andIgE;23.24.25.IV.FunctionsofTcells1.CD4+helperTcells(Th)Th3:produceTGF-β.inhibitTh1mediatedimmunityandinflamation

inhibitfunctionofB,Tc,NKTh17:secreteIL-17.innateimmunityandinflammation26.2.

CD8+cytotoxicTcells(CTL,Tc)Function:directlykilltargetcells(cytotoxicity)Mechanisms:

27.3.

CD4+CD25+regulatoryTcells(Tr)Foxp3positive

Function:

Down-regulationofimmuneresponsebyinhibitingtheactivationandproliferationofCD4+orCD8+Tcells.

Mechanisms:Directinhibitionbycontactingtargetcells.Inhibitorycytokines:IL-10,TGF-,etal.

28.©2005Elsevier29.Bcell

30.I.DevelopmentofBcellBlymphocytesrefertoBonemarrow-derivedlymphocytesorBursa-derivedlymphocytesAbout20％ofthecirculatinglymphoidpoolareBcells.31.DevelopmentofBcellinBM32.Ⅱ.B-cellsurfacemarkers33.1.BCRcomplexBCR(mIg)：VH,VL----Ag

matureBcells:mIgMandmIgD.

Function:specificallyrecognizesantigen.

Ig/Ig(CD79a/CD79b):heterodimercytoplasmicdomainscontainITAM.

Function:1.transfersthesignalsthatleadtoBcellactivation.

2.

transportstheIg34.2.Co-receptors:CD19/CD21/CD81complex35.3.Co-stimulatorymolecules(1)CD40(2)CD80/CD86(3)ICAM-1,LFA-136.4.OtherreceptorsCD20:BcellmarkerCD22:inhibitoryreceptorCD32:FcRⅡ37.38.

B-cellsubsetsB1cells(CD5+):ManyofthefirstBcellsthatappearduringontogenyexpressCD5,amarkeroriginallyfoundonTcells.(expressmIgM,nomIgD).TheyrespondwelltoTI-AgandmayalsobeinvolvedintheAgprocessingandpresentationtoTcells.

Functions

1.produceanti-bacterialIgMthefirstlineofdefenceagainstmicroorganisms;2.producepolyreactiveAbclearanceofdenaturedselfcomponents;3.produceauto-Ab,therebyparticipatinginthepathogenesisofsomeautoimmunediseases.

39.B2cell:CD5-Bcells.mIg:IgM,IgDafterantigenicstimulation,inthepresenceofTh,theyproducemoreIgGthanIgM40.B1andB2cellB1B2CD5+-renewingSelfrenewingDerivedfromBMSpontaneouslyIgproductionHighLowAntigenCarbohydrateProteinClassofIgIgM>IgGIgG>IgMSpecificityMulti-specificityMono-specificitySomaticHypermutationLow/noHighmemory-+41.NKCells

42.NKcellsweredefinedinitiallybytheirabilitytolysecertaintumorcelllinesandvirallyinfectedcellswithoutpriorimmunization,andsomediateaformofinnate(ornatural)immunitythatistermed“naturalkilling〞.43.I.OntogenyanddistributionofNKcellDerivefromabonemarrowprecursorlargegranularlymphocytesdistribution:peripheralblood,spleenNKcellsarerareinlymphnodeanddonotcirculatethroughthelymph.

44.II.Surfacemarkers1.CD562.CD16(Fc

RIII):ADCC3.CD24.CD11a/CD18(LFA-1)TheyneverthelessservetoidentifyNKcells,whicharegenerallyCD16+,CD56+,CD3-,whereasTcellsareCD16-,CD56-,CD3+.45.5.NKcellsreceptorsKAR(killercellactivationreceptor，杀伤细胞活化受体):CD94/NKG2CITAM(immnoreceptortyrosine-basedactivationmotif,-YxxL/Vx(7-11)YxxL/V-)ligand:saccharideKIR(killercellinhibitoryreceptor，杀伤细胞抑制受体):CD94/NKG2AITIM(immnoreceptortyrosine-basedinhibitorymotif,I/VxYxxL)ligand:classIMHCmoleculesIntracellularsignalingpathwayscoordinateinhibitoryandactivatingsignals46.Downloadedfrom:StudentConsult(on1June200601:58PM)©2005Elsevier47.III.FunctionsofNKcells1.Anti-infection

provideanearlyinnatebarriertoinfectionbyeliminatinginfectedhostcell2.Anti-tumor

killtumorcellsdirectly:perforin,granularenzyme

ADCC3.Immunoregulation

producecytokinessuchasIFN-

,TNF-

,G-CSF48.Antigen-presentingcells抗原提呈细胞49.ProfessionalAPCs:Dendriticcells;Monocytes/macrophagesandBcellsClassificationofAPCs50.

ClassificationofAPCs

Non-professionalAPCEndothelialcell(EC)FibroblasticcellActivatedTcellInducibleexpressionofMHCclassIImoleculesTargetcells

ExpressionofMHCclassImolecules51.BonemarrowBloodTissueHSCMyeloidprogenitorPre-monocyteMonocyteMonocyteMacrophageIIMonocytesandmacrophages

1.Differentiationanddistribution52.

MHC-IandIImolecules;CAM:LFA-1,ICAM-1,B7,CD40;CKR:M-CSFR;FcR;CR:CR1,CR3,CR4;Pattern-recognitionreceptor(PRR):mannosereceptor,scavengerreceptor,Toll-likereceptor

2.

Surfacemarkers53.3.BiologicalfunctionsofM

(1)Phagocytosisandcytotoxicactivity:

chemotaxis:blood----tissueopsonization:Ig,C3b,C4banumberofantimicrobialandcytotoxicsubstancesproducedbyactivatedMcandestroyphagocytosedmicroorganisms.

Reactiveoxygenintermediates,NO,proteinases.54.phagocytosis55.(2)Antigenprocessingandpresentation:phagocytosispinocytosisreceptor-mediatedendocytosis56.(3)Secretionofsolublefactorstoregulateimmuneresponse

enzymes:lysozyme,myeloperoxidase,etc.cytokines:IL-1,IL-6,TNF,IL-12,IL-18,etc.complement:C1~C9,Bfcoagulationfactor,PG,LTs,ACTH,etc.57.Dendriticcells

(DCs，树突状细胞)58.1.Surfacemarkers(1)MHCclassIImolecule(2)Specificmarks:CD1a,CD11c,CD83(human);33D1,NLDC145(mouse)(3)Co-stimulatorymolecules:CD80,CD86,CD40,CD44,CD54,integrinβ1,β2(4)Receptor:FcR,TLR,59.GM-CSFTNF-aIL-42.ClassificationofDC:originofDCHSCMyeloidprogenitorLymphoidprogenitorMyeloidDCMomacrophageMyeloid

DC

PMNLymphoid

DC60.2.ClassificationofDC:61.DendriticCellMaturation62.MigratingDC63.2.ClassificationofDC:distributionLymphoidtissueDC

follicularDC(FDC),interdigitatingDC(IDC),thymicDCNon-lymphoidtissueDCLangerhanscell,interstitialDCCirculatingDCperipheralbloodDC,veiledcell64.4.FunctionofDCAntigenpresentingandactivationofadaptiveTcellsImmunoregulationMaintainanceandinductionofimmunetolerance65.Bcells66.67.ImmuneResponse免疫应答68.ImmuneResponse〔免疫应答〕innateimmuneresponse(固有免疫应答)naturalimmuneresponsenon-specificimmuneresponseadaptiveimmuneresponse〔适应性免疫应答〕acquiredimmuneresponsespecificimmuneresponse69.Innateandadaptiveimmunity70.innateimmuneresponse

Physiologicalbarriersskinmucousmembranes

Phagocytosispolymorphonuclearleukocytes(PMN)macrophagesToll-likereceptor4/LPS

Naturalkiller(NK)cell

Complement,Acutephaseproteins

71.innateimmuneresponse72.innateimmuneresponse(Lung)MacrophageAttackingE.coli

73.Adaptiveimmuneresponse74.ImmuneResponse75.FeaturesofInnateandAdaptiveImmunity76.Tcell-mediatedimmuneresponse

77.TypesofintracellularmicrobescombatedbyTcell-mediatedimmunity78.PhasesofTcellresponsesThreephasesAntigenrecognitionphaseActivation,proliferationanddifferentiationphaseEffectorphase79.80.81.Ⅰ.Antigenrecognition

1AgpresentationbyAPC82.Antigenprocessingandpresentation83.I.Uptakeofantigens84.YThesiteofpathogenreplicationormechanismofantigenuptakedeterminestheantigenprocessingpathwayusedYCytosoliccompartmentEndogenousprocessing(Viralantigens)VesicularCompartmentContiguouswithextracellularfluidExogenousprocessing(Streptococcal,Mycobacterialantigens)DistinctmechanismsofantigengenerationareusedtoraiseTcellssuitedtotheeliminationofendogenousorexogenouspathogensINTRACELLULARREPLICATIONEXTRACELLULARORENDOSOMALREPLICATION85.86.1.ThepathwayofMHCI-associatedendogenousAgpresentationendogenousantigen(suchasvirusAg,tumorAg)

antigenpeptide〔8-13aa〕

Peptide/MHC-ImoleculecomplextosurfaceofAPCsubmittoCD8+TtransportedtoendoplasmicreticulumbyTAPdegradedbyproteasome(LMP)incytoplasm87.DegradationintheproteasomeThecomponentsoftheproteasomeincludeMECL-1,LMP2,LMP7.ThesecomponentsareinducedbyIFN-

andreplaceconstitutivecomponentstoconferproteolyticproperties.LMP2&7encodedintheMHCProteasomecleavesproteinsafterhydrophobicandbasicaminoacidsandreleasespeptidesintothecytoplasmCytoplasmiccellularproteins,includingnon-selfproteinsaredegradedcontinuouslybyamulticatalyticproteaseof28subunits88.Proteasome,theCytosolicMeatGrinderThatChopsUpProteins89.ENDOPLASMICRETICULUMCYTOSOLPeptideantigensproducedinthecytoplasmarephysicallyseparatedfromnewlyformedMHCclassINewlysynthesisedMHCclassImoleculesPeptidesneedaccesstotheERinordertobeloadedontoMHCclassImoleculesLMPTAP90.ERmembraneLumenofERCytosolTransporter-associatedwithantigenprocessing(TAP1&2)Transporterhaspreferencefor>8aminoacidpeptideswithhydrophobicCtermini.TAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideERmembraneLumenofERCytosolTAP-1TAP-2PeptideATP-bindingcassette(ABC)domainHydrophobictransmembranedomainPeptideantigensfromproteasome91.EndoplasmicreticulumCalnexinbindstonascentclassI

chainuntil

2-MbindsTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2PeptideTAP-1TAP-2Peptide

2-MbindsandstabilisesfloppyMHCTapasin,calreticulin,TAP1&2formacomplexwiththefloppyMHCCytoplasmicpeptidesareloadedontotheMHCmoleculeandthestructurebecomescompactMaturationandloadingofMHCclassI92.93.2.ThepathwayofMHCII-associatedexogenousAgpresentationExogenousantigennewlysynthesisedMHCclassIImolecule

(intheendoplasmicreticulum)endosomeIibindsinthegrooveofMHCclassIImolecule

lysosomeproteaseMIICphagolysosomeli(CLIP)proteaseDMDegradeinto1318aapeptide+releasingtheCLIPandallowingotherpeptidetobind

Agpeptide/MHCclassIImoleculecomplextransporttothesurfaceofAPC,recognizedbyCD4+TPhagocytosis,pinocytosis,FcR-phagocytosis94.YYPinocytosisPhagocytosisMembraneIgreceptormediateduptakeYUptakeofexogenousantigensComplementreceptormediatedphagocytosisYFcreceptormediatedphagocytosisopsonization95.Proteasesproduce~24aminoacidlongpeptidesfromantigensEndosomesExogenouspathwayIncreaseinacidityCellsurfaceTolysosomesUptakeProteinantigensInendosomeCathepsinB,DandLproteasesareactivatedbythedecreaseinpH96.PathwayforPeptide+MHC-IIFormation,fromEndocytosisProteinsintoVesiclestoFormationofPeptidesonMHC-II97.Needtopreventnewlysynthesised,unfoldedselfproteinsfrombindingtoimmatureMHCInvariantchainstabilisesMHCclassIIbynon-covalentlybindingtotheimmatureMHCclassIImoleculeandforminganonomericcomplexIntheendoplasmicreticulumMHCclassIImaturationandinvariantchain98.involveintheassemblingandfoldingofMHCclassIImolecule;BlockthegrooveofMHCclassIImolecule;LeadtheassembledclassIImoleculetoMIIC.ThefunctionsofIi:CLIP：classII-associatedinvariantchainpeptide99.EndosomesCellsurfaceUptakeClassII-associatedinvariantchainpeptide(CLIP)(-Ii)3complexesdirectedtowardsendosomesbyinvariantchainproteasedegradesInvariantchainCLIPblocksgrooveinMHCmoleculeMHCClassIIcontainingvesiclesfusewithantigencontainingvesicles100.HLA-DMcatalysestheremovalofCLIPMIICcompartmentHLA-DMReplacesCLIPwithapeptideantigenusingacatalyticmechanism(i.e.efficientatsub-stoichiometriclevels)DiscoveredusingmutantcelllinesthatfailedtopresentantigenHLA-DOmayalsoplayaroleinpeptideexchangeSequenceincytoplasmictailretainsHLA-DMinendosomesHLA-DMHLA-DR101.MIICcompartmentsortspeptide-MHCcomplexesforsurfaceexpressionorlysosomaldegradationSurfaceexpressionofMHCclassII-peptidecomplexesExportedtothecellsurface(t1/2=50hr)Senttolysosomesfordegradation102.MHC-IIGoesfromGolgi(G)toMHC-IICompartment(MIIC)WherePeptideLoadingOccurs103.104.105.106.3.Cross-presentationClassIMHCmoleculespresentexogenousAgstoCD8+TcellsCross-presentationofAgsbyDCplaysanimportantroleinanti-viralinfectionandanti-tumorimmunity.107.3.Cross-presentation108.4,CD1-mediatedantigenpresentingpathway109.110.2,Interactionbetween

APCandTcellNonspecificbindingofAPCandTcellSpecificbindingofAPCandTcellTCR-peptide-MHCco-receptor-MHCco-stimulatorymoleculesTcellsynapseorimmunologicalsynapse

111.Ligand-receptorpairsinvolvedinTcellactivation112.

MaincostimulatorymoleculesmediatinginteractionsbetweenTcellsandAPCs113.3activation,proliferationanddifferentiation

Thefirstsignal

TCR-antigenpeptide-MHC(doublerecognition)CD4-MHCIIorCD8-MHCIThesecondsignal(co-stimulatorysignal)Interactionsbetweenco-stimulatorymoleculesonAPCandcorrespondingreceptorsonTcells

CD28/CTLA-4—B7,LFA-1—ICAM-1,LFA-2—LFA-3

CytokinesinTcellactivation

IL-1,2,6,12

114.115.ProliferationanddifferentiationofTcells1)CD4+Tcells:Th,Tr,Treg,Th17,Tmregulatedbycytokines2)CD8+Tcells:Tc

Th-dependent

Th-independent:virusinfectedDCthathighlyexpressco-stimulatorymoleculescandirectlystimulateCD8+Tcells.

116.ActivationofCD8+Tcells117.

CytokinesarerequiredinTcell

proliferationanddifferentiation

ActivatedTcellscanproducecytokines

(IL-2,

4,

7,

10,

etc.)andexpresscytokinereceptors,thatpromoteTcellstoproliferateanddifferentiate.118.4.EffectorfunctionsofactivatedTcells1)

CD4+Tcells

Th1:secreteIFN-,etc.expressCD40LexpressFasL,killFas+targetcellseffectonlymphocytes:IL-2effectonneutrophil:TNF-,

Th2:promoteBcellgrowthandIgproductionmediatehypersensitivityTh17:IL-17,Il-8,TNF-:enhanceleukocyterecruitmentandinflammation

Activatemacrophages119.Twotypesofcell-mediatedimmunity120.Cell-mediatedimmunityagainstintracellularmicrobes121.ActivationofmacrophagesbyTlymphocytes122.Cytotoxicity:killtargetcellsa.necrosis:perforinandgranzymeb.apoptosis:granzyme,FasLCharacteristicsofCD8+Tcellcytotoxicitya.

Specificityb.MHCIrestrictionc.Highefficiency2)CD8+Tcells123.Downloadedfrom:StudentConsult(on1June200603:50PM)©2005ElsevierMechanismsofkillingofinfectedcellsbyCD8+CTLs124.125.3)memoryTcells1)CD45RA-CD45RO+,2)Long-livedmemorytospecificantigen3)Mediatefaster,strongerandmoreeffectiveimmuneresponse4)Mechanism:lowdependentoncostimulatorymoleculesormoresensitivitytocytokines126.Activationinducedcelldeath,AICD1)Activationinducedcelldeath

ActivatedTcellsexpressFasLthatinduceapoptosisofFaspositiveTcells.2)PassivecellapoptosisAg,survivalsignalsandgrowthfactors127.Activation-induceddeathofTcells128.Bcell-mediatedhumoral

immuneresponseHumoralimmunityismediatedbyantibodiesandisthearmoftheadaptiveimmuneresponsethatfunctionstoneutralizeandeliminateextracellularmicrobesandmicrobialtoxins.129.

Phasesandtypesofhumoral

immuneresponses

1)PhasesAntigenrecognitionphaseActivation,proliferationanddifferentiationphaseEffectorphase2)TypesResponsetoTD-AgResponsetoTI-Ag130.PhasesofhumoralimmuneresponsesEffectorphase131.1)BcellsrecognizeTD-Aga.BCRdirectlyrecognizesBcellepitopesb.Ig

/Ig

transferthefirstsignalc.Effectofcoreceptors(CD21/CD19/CD81)d.Signallingpathways132.Theroleofcoreceptor(CD19/CD21/CD81)inBcellactivation133.2)RoleofThcellsinhumoral

immuneresponsetoTD-AgForaproteinAgtostimulateAbresponse,BcellsandThcellsspecificforthatAgmustcometogetherinlymphoidorgansandinteractinawaythatstimulatesBcellproliferationanddifferentiation.134.a.ActivationandmigrationofhelperTcellsThcellsthathavebeenactivatedtodifferentiateintoeffectorcellsinteractwithantigen-stimulatedBcellsattheedgesoflymphoidfolliclesintheperipherallymphoidorgans.135.TheinteractionsofThcellsandBcellsinlymphoidtissues.136.b.PresentationofAgsbyBcellstoThcellsBcellsthatbindproteinAgsbytheirBCRendocytosetheseAgs,processtheminendosomalvesicles,displayMHCII-peptidesforrecognitionofThcells.BcellsandThcellsrecognizedifferentepitopesofthesameproteinAg.137.AgpresentationbyBcellstoThcells138.139.c.MechanismsofThcell-mediated

activationofBcellsThcellsthatrecognizeAgpresentedbyBcellsactivatedBcellbyexpressingCD40Landbysecretingcytokines(IL-2,IFN-

,IL-4,IL-5,IL-6,IL-13,etc.).140.Downloadedfrom:StudentConsult(on1June200603:50PM)©2005ElsevierMechanismsofThcell-mediatedactivationofBcells141.Theanatomyofhumoralimmuneresponses142.

2)BcellmaturationinGerminalcen