抗肿瘤免疫机制

抗肿瘤免疫机制

MechanismofImmuneResponsetoTumor细胞免疫抗肿瘤作用体液免疫抗肿瘤作用细胞因子抗肿瘤的作用TumourantigensrecognizedbyTlymphocytes:atthecoreofcancerimmunotherapy.NATUREREVIEWS|CANCERVOLUME14|FEBRUARY2014细胞免疫抗肿瘤作用一、T细胞二、NK细胞三、NKT细胞四、巨噬细胞(M)T细胞在抗肿瘤的特异性免疫中是主要效应细胞。1.T细胞的分化、成熟和活化2.T细胞抗肿瘤的效应机制一、T细胞T细胞的分化、成熟和活化T细胞在胸腺中分化、成熟T细胞抗原受体和相关分子抗原的识别和T细胞活化、增殖MostoftheimmaturethymocytesinthethymusdieeitherbecausetheymakeanunproductiveTCR-generearrangementorbecausetheyfailpositiveornegativeselection.ThreematureT-cellpopulations(green,pink,blue)areproducedandmovetotheperipherallymphoidorgans.MostTcellsexpresstheTCRandeitherCD4(blue)orCD8(pink).AfewTcellsexpresstheTCR(green);mostoftheselackbothCD4andCD8.NotethattheboundarybetweentheearlyandthelatephaseofT-celldevelopmentisnotsharp.T细胞在胸腺中分化、成熟

Positiveandnegativeselectionofthymocytesinthethymus.Thymicselectioninvolvesthymicstromalcells(epithelialcells,dendriticcells,andmacrophages),andresultsinmatureTcellsthatarebothself-MHCrestrictedandself-tolerant.Positiveandnegativeselectionofthymocytesinthethymus阳性选择（positiveselection）

在胸腺皮质中，CD4+CD8+双阳性T细胞，其TCR能与胸腺基质细胞表面的MHCⅠ/Ⅱ类分子-抗原肽结合，且具适当（低）亲和力的DP细胞分化为单阳性（SP）T细胞，其中与Ⅰ类分子结合的DP细胞分化为CD8+T细胞（SP）；与Ⅱ类分子结合的DP细胞分化为CD4+T细胞（SP）；而不能与MHC-抗原肽结合或高亲和力的DP细胞则发生凋亡遭克隆清除。此过程也称为胸腺的阳性选择。生物学意义：赋予成熟的T细胞具有MHC限制性。经历阳性选择的SP细胞在胸腺的皮髓质交界处及髓质区还须经历阴性选择：凡是能识别自身抗原-MHC复合物、且具有高亲和力的SP细胞发生凋亡遭克隆清除，其实质是清除自身反应性T细胞，即阴性选择。生物学意义：赋予成熟的T细胞具有自身免疫耐受（中枢）的特性。

T细胞经三个发育阶段及胸腺选择后成为成熟T细胞，迁出胸腺进入外周T细胞库。阴性选择（negativeselection）

T细胞抗原受体和相关分子

HomingoflymphocytesExamplesofhomingreceptorsandvascularaddressinsinvolvedinselectivetraffickingofnaïveandeffectorTcells.(a)NaïveTcelltendtohometosecondarylymphoidtissuethroughtheirHEVregions.(b,c)VarioussubsetsofeffectorTcellsexpresshighlevelsofparticularhomingreceptorsthatallowthemtohometoendotheliuminparticulartertiaryextralymphoidtissues.抗原的识别和T细胞活化、增殖膜表面分子相互作用

OverviewofTCR-mediatedsignaling.TCRengagementbypeptide-MHCcomplexesinitiatestheassemblyofasignalingcomplex.AnearlystepistheLck-mediatedphosphorylationofITAMsonthezetachainsoftheTCRcomplex,creatingdockingsitestowhichtheproteinkinaseZAP-70attachesandbecomesactivatedbyphosphorylation.AseriesofZAP-70-catalyzedproteinphosphorylationsenablethegenerationofavarietyofsignals.信号转导效应功能CD4+T细胞CD8+T细胞

δ+T细胞Treg细胞T细胞抗肿瘤的效应机制CD4+T细胞CD8+T细胞增殖分化杀伤效应

杀伤肿瘤细胞过程分为效靶细胞结合，攻击杀伤和靶细胞裂解。显示对肿瘤细胞效应功能具有高度的特异性和有效性。StagesinCTL-mediatedkillingoftargetcells

Comparisonofmorphologicchangesthatoccurinapoptosisandnecrosis.Apoptosis,whichresultsintheprogrammedcelldeathofhematopoieticcells,doesnotinducealocalinflammatoryresponse.Incontrast,necrosis,theprocessthatleadstodeathofinjuredcells,resultsinreleaseofthecells’contents,whichmayinducealocalinflammatoryresponse.

Apoptosis.Lightmicrographsof(a)normalthymocytes(developingTcellsinthethymus)and(b)apoptoticthymocytes.Scanningelectronmicrographsof(c)normaland(d)apoptoticthymocytes.TheCancer-ImmunityCycle.Thegenerationofimmunitytocancerisacyclicprocessthatcanbeselfpropagating,leadingtoanaccumulationofimmune-stimulatoryfactorsthatinprincipleshouldamplifyandbroadenTcellresponses.Thecycleisalsocharacterizedbyinhibitoryfactorsthatleadtoimmuneregulatoryfeedbackmechanisms,whichcanhaltthedevelopmentorlimittheimmunity.Thiscyclecanbedividedintosevenmajorsteps,startingwiththereleaseofantigensfromthecancercellandendingwiththekillingofcancercells.Eachstepisdescribedabove,withtheprimarycelltypesinvolvedandtheanatomiclocationoftheactivitylisted.Abbreviationsareasfollows:APCs,antigenpresentingcells;CTLs,cytotoxicTlymphocytes.OncologyMeetsImmunology:TheCancer-ImmunityCycle.Immunity39,July25,2013CD4调节性T细胞的分化及功能特点自然调节T细胞（CD25+Foxp3+nTreg）直接分化于胸腺，通过细胞间接触以CTLA-4等行使抑制功能。适应性调节T细胞（CD25+Foxp3+iTreg）在TGF-

及IL-2诱导下自nTreg或Foxp3-T细胞产生，借助分泌IL-10和TGF-

发挥抑制作用。另外两种调节T细胞（Tr1和Th3）分化自CD25-Foxp3-T细胞，其中Tr1的产生由多种因素（IL-10,VitD3,imDC）参与诱导，通过分泌IL-10和TGF-

发挥作用。免疫抑制CTLA-4IL-10,TGF-

Foxp3+nTreg

Th3Tr1Foxp3+iTreg胸腺TGF-

TGF-

IL-10等

自身肽-MHCII亲和力(

)自身肽-MHCII亲和力(

)CD25+Foxp3+TCD25－Foxp3－TIL-10,TGF-

起源细胞前体调控因素Treg亚群效应分子功能Treg细胞

δ+T细胞Timecourseofappearanceof

thymocytesand

thymocytesduringmousefetaldevelopment.ThegraphshowsthepercentageofCD3+cellsinthethymusthataredouble-negative(CD4

8

)andbearthe

T-cellreceptor(black)oraredoublepositive(CD4+8+)andbearthe

T-cellreceptor(blue).

δ+T细胞是指TCRγ和δ链构成的T细胞，在T细胞中占<5%。通常表达CD3和CD56分子，大多数不表达CD4和CD8分子。

该TCR直接识别磷酸抗原和某些单一肽类分子配体。在抗肿瘤作用中，主要通过分泌多种细胞因子，如IL-2、IL-4、IFN-γ和TNF-α等，其作用类似于CD4+T细胞；其效应作用可释放胞内的细胞毒颗粒杀伤靶细胞，其作用类似于CD8+T细胞，但杀伤作用不受MHC限制性。Tumorcellligandsrecognizedbyhuman

Tcellsandstrategiesfor

Tcell–basedimmunotherapy.Leftpanel,thedominantpopulationofV

2V

9TcellsrecognizesviaitsTCRnonpeptidicphosphoantigens,suchasthenaturallyoccurringisoprenoidmetaboliteIPP,thesyntheticbromohydrinpyrophosphate(BrHPP;Phosphostim),aminobisphosphonates(N-BP),theectopicallyexpressedF1-ATPase,andapolipoproteinA-I.LigandsrecognizedbytheV

1TCRhavebeenlesswelldefinedbutincludeMICA.Inaddition,MICA/MICBandULBPsfrequentlyexpressedontumorcellsareligandsfortheactivatingNKreceptorNKG2D,whichispresentonV

1andV

2

Tcells.Rightpanel,strategiesfor

Tcell–basedimmunotherapyinclude(i)theadoptivecelltransferofinvitroexpanded

Tcellsand(ii)theinvivoactivationofV

2V

9Tcellsbyphosphoantigens(e.g.,bromohydrinpyrophosphate/Phosphostim)oraminobisphosphonatesandlow-doseIL-2.V

2V

9Tcellscanbereadilyactivatedandexpandedinvitrobyphosphoantigens(bromohydrinpyrophosphate)oraminobisphosphonatesinthepresenceofIL-2.PossiblebeneficialeffectsofadditionalNKG2DstimulationbyactivatingantibodiesornaturallyoccurringNKG2Dligandsrequirefurtherinvestigation.Intheabsenceofdefinedligands(exceptforMICA)thatarerecognizedbytheV

1TCR,tumor-reactiveV

1

Tcellscanbeactivatedandexpandedinvitrobystimulationwithmitogenicanti-TCRantibodiesandIL-2intheabsenceorpresenceofadditionalNKG2Dligation.Ligandsrecognizedbyhuman

TcellStrategiesfor

Tcell-basedimmunotherapyTCRNKG2DNKG2DTCRAPO-A-1F1-ATPaseIPP,BrHPP,NBPMICA/BULBPsULBPsMICA/BV

1V

2AdoptivecelltransferInvivoactivation+BrHPPorNBP+IL-2+/-NKG2DBrHPPorNBP+IL-2+anti-TCRantibody+IL-2+NKG2DV

1V

2CancerRes2007;(67):1,5-8二、NK细胞

NK细胞是抗肿瘤免疫早期起重要作用的效应细胞，参与非特异性免疫和特异性免疫。主要通过受体介导杀伤作用和抗体依赖的细胞介导的细胞毒作用。1.NK细胞的特性2.NK细胞的效应功能NK细胞特性NK细胞是一类对多种靶细胞自发性细胞毒活性的淋巴细胞谱系的特殊亚群，不表达T、B细胞特有表面标志物（TCR、BCR、CD4和CD8等），人类NK细胞表达CD16和CD56等分化抗原，占外周淋巴细胞的10-15%。效应功能：ADCC＋LAK＋＋＋天然细胞毒＋CD56brightIL-2c-kitCCR7CD16dimL-selectinhighNKR：KIR＋CD94-NKG2A＋＋＋高分泌细胞因子：GM-CSF,TNF-/-IFN-

,IL-10CD94-NKG2ACD16brightKIRNKR：KIR＋＋＋CD94-NKG2A＋CD56dimIL-2RCXCR1CX3CR1

效应功能：

ADCC＋＋＋

LAK＋＋＋天然细胞毒＋＋＋

低分泌细胞因子PEN5-PSGL-1CD56brightNK和CD56dimNK细胞亚群的特征识别HLA

Ι类分子的抑制或活化受体①杀伤细胞免疫球蛋白样受体(KIR)②杀伤细胞凝集素样受体(KLR)识别非HLA

Ι类分子的活化受体①NKG2D②自然细胞毒性受体(NCR)NK细胞杀伤活性受体和抑制受体RecognitionoftumourcellsbyNKcells.a|Naturalkiller(NK)cellsaretoleranttohealthyhostcells,asthestrengthoftheactivatingsignalstheyreceiveonencounteringthesecellsisdampenedbytheengagementofinhibitoryreceptors(tolerance).b|TumourcellsmayloseexpressionofMHCclassImolecules.NKcellsbecomeactivatedinresponsetothesecells,astheyarenolongerheldincheckbytheinhibitorysignaldeliveredbyMHCclassImoleculeengagement.Thisisknownas‘missing-self’triggeringofNKcellactivation.c|Inaddition,NKcellsareselectivelyactivatedby‘stressed’cells,whichupregulateactivatingligandsforNKcellsandtherebyovercometheinhibitorysignallingdeliveredbyMHCclassImolecules.Thisisknownas‘stress-inducedself’triggeringofNKcellactivation.Inbothconditions,NKcellactivationleadstotumoureliminationdirectly(throughNKcell-mediatedcytotoxicity)orindirectly(throughtheproductionofpro-inflammatorycytokines,suchasinterferon‑γ).TargetingnaturalkillercellsandnaturalkillerTcellsincancer.NATUREREVIEWS|IMMUNOLOGYVOLUME12|APRIL2012NK细胞识别模式（1986年Karre等）NK细胞的“丢失自我”和“诱导自我”识别模式早期NK细胞与表达MHCI类分子的正常细胞（教育细胞）相互作用，获得辨别自身正常细胞的能力（称为受教育），当此NK细胞接受IL-15等多种细胞因子刺激后进一步激活（被致敏）。B.NK细胞活化性受体及抑制性受体间的平衡，决定NK细胞是否激活并对靶细胞实施杀伤。右上：健康细胞I类分子与NK细胞抑制性受体结合，产生的抑制信号抑制活化性受体活性，NK细胞不杀伤靶细胞（耐受状态）。右中和右下：受到应急诱导的细胞（肿瘤或病毒感染细胞）I类分子表达下调（“丢失自我”识别模式），或活化性配体表达上调（“诱导自我”识别模式），抑制信号不能发挥作用，导致NK对靶细胞的杀伤。受教育MHCI类分子MHC

I类专一抑制性受体IL-12IL-12RIL-18IL-18RIL-2,IL-15IL-2R,IL-15R(

链+c)IL-21IL-21RIFN-

IFN-R

-活化受体活化配体耐受状态丢失自我诱导自我

被致敏教育细胞NK

健康细胞应急细胞NKNKNK

-应急细胞NKABMHCI类分子MHC

I类专一抑制性受体DNA损伤,肿瘤恶变,病毒感染NK细胞IFN-,TNF-等细胞因子M

树突状细胞应急诱导性靶细胞ADCCT细胞靶细胞裂解清除应急诱导性靶细胞抗原提呈

正常细胞抗原提呈NK细胞的免疫生物学功能NK细胞可以识别并以抗体依赖细胞介导细胞毒（ADCC）形式杀伤多种应急诱导的靶细胞(如DNA损伤细胞、肿瘤细胞和病毒感染细胞等），NK细胞还可以促进DC细胞成熟和发挥抗原提呈功能，参与激活T细胞。另外，NK细胞可以通过分泌IFN-,TNF-或IL-10的方式来提高或者降低巨噬细胞或树突状细胞的活性。NK细胞的效应功能杀伤作用和免疫调节诱导活化产生IFN-/，TNF-,IL-12NK细胞在抗病毒中的作用

小鼠实验表明，病毒感染后体内最早出现的是I型干扰素、TNF-

和IL-12，以及由NK细胞参与的杀伤，然后是病毒特异性细胞毒性T细胞（CTL）发挥作用，病毒滴度下降。三、NKT细胞CD1dDN-TDP-TSP-TNKTTCR-NKT前体CD4+CD8+MHCIIMHC

IMHC

IMHC

II凋亡凋亡

自然杀伤T细胞(naturekillerTcells,NKT)是一群细胞表面具有TCR又表达NK细胞受体的淋巴细胞亚群。NKT细胞的分化发育主流前体模式:NKT细胞与传统T细胞一样在胸腺中发育，由CD4+CD8+双阳性(DP)T细胞经CD1d分子的选择，逐渐脱离主流分化途径，获得NK细胞表型，最终形成NKT细胞，进入外周血、肝脏和脾脏中。特定前体模式：NKT细胞通过非胸腺依赖的途径发育分化，即从可能存在的NKT前体细胞独立地在外周器官(如肝脏)中分化成熟。DN-T：双阴性(CD4-CD8-)T细胞；SP-T：单阳性(CD4+或CD8+)T细胞。

NKT细胞识别由细胞表面CD1分子递呈的脂类抗原。NKT细胞识别抗原不同于T细胞,但它们的激活和T细胞一样需要共刺激信号。NKT细胞（经典）的TCR识别DC的CD1递呈的

-半乳糖神经酰胺(

-galactosylceramide,

-GalCer),同时,其表面的CD28及CD154(CD40L)分别与DC表面的CD80/CD86(B7-1/B7-2)及CD40相互作用,在激活DC产生IL-12及IL-18同时使NKT细胞表面的IL-12R与IL-18R表达上调。NKT细胞被IL-12与IL-18进一步激活,产生高水平的IFN-

与IL-4。由脾脏等外周NKT细胞受到刺激后主要产生IFN-

。NKT细胞对抗原的识别Cellularandmolecularmechanismsofantitumorimmuneresponsesmediatedbyα-GalCer-activatedNKTcells.Theα-GalCer/CD1dcomplexactivatesNKTcellstoupregulateCD40Landcytotoxicmoleculeexpressions.CD40LonNKTcellsstimulatesCD40onDC,leadingtotheiractivationtoproduceIL-12.IL-12fromDCactivatesNKTcellstoproduceIFN-γwhichinturnstimulatesNKcellsandCD8CTLsmediatingantitumorcytotoxicity.α-GalCer-activatedNKTcellsalsoinducematurationofDC,whichcontributestotheupregulationofTh1responses.免疫调节：NKT细胞激活后，可通过分泌IL-4和IFN-

调节Th细胞的分化,对免疫应答和自身免疫的调节。

-半乳糖神经酰胺NaturalkillerT(NKT)cellsrecognizeglycolipidsboundtoCD1datthesurfaceofantigen-presentingcells(APCs).ActivatedNKTcellssecreteIFN-γinaCD40-andIL-12-dependentmannerandcanlysetumorcellsthoughanMHC-unrestricted,TRAILorperforin-dependentpathway.细胞毒作用：NKT细胞被活化后，可分化成具有细胞毒性和杀伤活性的效应细胞,在免疫、保护性免疫应答中发挥抗肿瘤作用。NKT细胞效应功能AntitumouractivitiesofiNKTcells.a|TumourcellsthatexpressCD1dcanbedirectlyrecognizedbyinvariantnaturalkillerT(iNKT)cellsandsubsequentlyeliminatedeitherdirectly,byiNKTcellactivity,orindirectlyviaiNKTcell-mediatedactivationofnaturalkiller(NK)cells.b|AlthoughnotalltumourcellsexpressCD1d,iNKTcellscanalsobecomeactivatedinresponsetoCD1d‑expressingantigen-presentingcells(APCs).TheactivatediNKTcellsthenpromoteNKcellactivationandtherebyindirectlymediatetumourcellelimination.c|IthasalsobeenproposedthatiNKTcellscanlimittumourgrowthbysuppressingtheproductionofpro-angiogenicfactorsbymacrophages,althoughthisstillremainstobeconfirmed.TAM,tumour-associatedmacrophage;TCR,Tcellreceptor.TargetingnaturalkillercellsandnaturalkillerTcellsincancer.NATUREREVIEWS|IMMUNOLOGYVOLUME12|APRIL2012四、单核/巨噬细胞来源和组织分布表面标志生物学功能和调节单核/巨噬细胞的来源和组织分布单核巨噬细胞表面标志葡聚糖受体

甘露糖受体

Toll样受体

CR3LPS受体(CD14)

清道夫受体

B7分子

MHCI类分子

TNF-

CD40

NO

O2

TNF受体

MHCII类分子

AB巨噬细胞表达的受体和表面分子A.巨噬细胞；B.活化的巨噬细胞

巨噬细胞参与固有免疫和特异性免疫，杀伤肿瘤细胞机制主要为：①吞噬和杀伤作用；②介导炎症反应；③加工递呈抗原、启动免疫应答；④释放细胞因子参与免疫调节；⑤参与ADCC释放效应分子杀伤靶细胞。生物学功能和调节Mediatorsofantimicrobialandcytotoxicactivityofmacrophagesandneutrophils体液免疫抗肿瘤作用

体液免疫是指抗体所发挥的效应功能。一、B细胞的分化、成熟和活化、增殖二、生发中心的形成、体细胞突变和抗体类别转换三、B细胞抗原受体和信号转导四、体液免疫抗肿瘤效应机制一、B细胞的分化、成熟和活化、增殖

OverviewofB-celldevelopment.Duringtheantigen-independentmaturationphase,immuno-competentBcellsexpressingmembraneIgMandIgDaregeneratedinthebonemarrow.Onlyabout10%ofthepotentialBcellsreachmaturityandexitthebonemarrow.NaiveBcellsintheperipherydiewithinafewdaysunlesstheyencountersolubleproteinantigenandactivatedTHcells.Onceactivated,Bcellsproliferatewithinsecondarylymphoidorgans.Thosebearinghigh-affinitymIgdifferentiateintoplasmacellsandmemoryBcells,whichmayexpressdifferentisotypesbecauseofclassswitching.ThenumberscitedrefertoB-celldevelopmentinthemouse,buttheoverallprinciplesapplytohumansaswell.二、生发中心的形成、体细胞突变和抗体类别转换Germinalcentersaresitesofintensecellproliferationandcelldeath.Thephotomicrograph(leftpanel)showsahigh-powerviewofasectionthroughahumantonsillargerminalcenter.Closelypackedcentroblastsseeninthelowerpartofthisphotomicrographformtheso-calleddarkzoneofthegerminalcenter.Abovethisregionisthelessdenselypackedlightzone.Therightpanelshowsimmunofluorescentstainingofagerminalcenter.Bcellsarefoundinthedarkzone,lightzone,andmantlezone.ProliferatingcellsarestainedgreenforKi67,anantigenexpressedinnucleiofdividingcells,revealingtherapidlyproliferatingcentroblastsinthedarkzone.Thedensenetworkoffolliculardendriticcells,stainedred,mainlyoccupiesthelightzone.Centrocytesinthelightzoneproliferatetoalesserdegreethancentroblasts.SmallrecirculatingBcellsoccupythemantlezoneattheedgeoftheB-cellfollicle.LargemassesofCD4Tcells,stainedblue,canbeseenintheT-cellzones,whichseparatethefollicles.TherearealsosignificantnumbersofTcellsinthelightzoneofthegerminalcenter;CD4staininginthedarkzoneisassociatedmainlywithCD4-positivephagocytes.PhotographscourtesyofI.MacLennan.生发中心的形成TD抗原诱导体液免疫应答中顺序发生的事件T、B細胞穿越HEV；B细胞迁移至至淋巴滤泡获取抗原；C.留在T细胞区的T细胞被DC激活；D.T-B细胞发生相互作用；E.相互作用后的B细胞形成滤泡外原发灶；F.相互作用后的T细胞分化成Tfh，进入淋巴滤泡，并与该处的滤泡B细胞和滤泡树突状细胞相互作用，启动生发中心反应。CXCR5+CD4

Th2CCR7+BCXCR5+BCCR7+TCCR7+TDCCXCR5+CD4TfhABCDEFM

FDCCCR7+BCXCR5+B次级淋巴滤泡初级淋巴滤泡基质细胞和树突状细胞表达趋化因子CXCL13（CXCR5配体）基质细胞、血管内皮细胞、巨噬细胞和树突状细胞表达趋化因子CCL19/CCL21(CCR7配体）外周淋巴组织T

细胞区外周淋巴组织B

细胞区CXCR5+BBCR-AgCD40LCD40

滤泡外原发灶B7CD28

生发中心HEVCkCCR7+Bcl-6TfhICOSCD84(SLAM)SAPBCRPI3KMAFTCRCD40LMHCclassIICD40ICOSLBcl-6IRF8Bcl-2AIDBCL-XLPI3KTC21DOCK8MyD88CXCR5CXCR4CXCR5IgGFc

RCR2AgC3ICAM-1LFA-1Fc

RII-BCD95

CD95LIL-17RIL-4RIL-21RIL-21R