免疫學(xué)及免疫檢測(cè)技術(shù)論文翻譯

Armedandaccurate:engineeringcytotoxicTcellsforeradicationofleukemia裝備并確認(rèn)：工程細(xì)胞毒性T細(xì)胞根除白血病MarkoRadicCorrespondence:MarkoRadicmradic@AuthorAffiliationsThisisanOpenAccessarticledistributedunderthetermsoftheCreativeCommonsAttributionLicense(/licenses/by/2.0),whichpermitSunrestricteduse,distribution,andreproductioninanymedium,providedtheoriginalworkisproperlycited.AbstractTranslationalmedicinedependsonarapidandefficientexchangeofresultsbetweenthebenchandthebedside.Arecentexamplefromthefieldofcancerimmunotherapyhighlightstheessentialnatureofthisexchange.Methodshavebeendevelopedtoconvertapatient'scytotoxicTcellsintoefficientandspecifickillersofcancercellsinpatientswithleukemia.ByusingrecombinantDNAtechniques,alentiviralvectorwasconstructedtoexpresschimericantigenreceptorsincytotoxicTcellsfrompatientswithadvancedchroniclymphocyticleukemia.ThepurposeofthechimericreceptorswastodirectthecytotoxicTcellactivityagainstcellscausingthecancer.TheeffectofinfusingtheengineeredTcellsbackintothecancerpatientswastestedinaPhaseItrialattheUniversityofPennsylvania,andtheinitialresultsweredescribedintwoarticlesfromtheresearchteamofDr.CarlJune.Theremarkablesuccessofthistrialshouldenergizefurtherapplicationsofbiotechnologyinthedevelopmentofnewcancerimmunotherapies.轉(zhuǎn)化醫(yī)學(xué)取決于工作臺(tái)和病床間的快速，高效的轉(zhuǎn)換的結(jié)果。最近的一個(gè)例子，從癌癥的免疫療法領(lǐng)域突出這種交換的本質(zhì)。方法已被開(kāi)發(fā)是將患者的細(xì)胞毒性T細(xì)胞轉(zhuǎn)換成高效特異的癌細(xì)胞殺手。通過(guò)使用重組DNA技術(shù)，慢病毒載體構(gòu)建從先進(jìn)的慢性淋巴細(xì)胞白血病的患者的細(xì)胞毒性T細(xì)胞中表達(dá)嵌合抗原受體。嵌合受體的目的是指導(dǎo)細(xì)胞毒性T細(xì)胞對(duì)抗致癌細(xì)胞。I期臨床試驗(yàn)在美國(guó)賓夕法尼亞大學(xué)設(shè)計(jì)的工程T細(xì)胞注入到癌癥患者的影響進(jìn)行了測(cè)試，卡爾博士的研究小組的兩篇文章中描述了初步的結(jié)果。這項(xiàng)試驗(yàn)非凡的成功，應(yīng)該激勵(lì)在新的癌癥免疫療法的發(fā)展中進(jìn)一步應(yīng)用生物技術(shù)

MainTextRecentadvancesincancerimmunotherapyhaveallowedtheconversionofTcellsfromleukemiapatientsintoefficientandspecifickillersoftheirowncancercells.Thenewtechniquehasbeenrecentlytestedwithremarkableresults.Theoutwardsignsofthesuccessfultherapyweredramaticandclear.Thecancerpatientsshookwithfever,chillsandpain;theirbloodpressureprecipitouslydropped.TheydriftedinandoutofsleepfordaysfollowingtheinfusionoftheirownengineeredkillerTcells.TheinternalstrugglepeakedbetweentwoandthreeweeksafterTcellreinfusion.Theloadoflysedcancercellsstressedandnearlypoisonedthepatients'kidneys.Theirimmunesystems,reinvigoratedbytheimmunotherapy,haddestroyednearly1kgofcancercells.Nootheravailabletreatmentcouldhaveachievedacomparabletherapeuticsuccess.Thenewtreatment,administeredbyDr.CarlJuneandhiscolleaguesoftheAbrahamsonCancerCenterattheUniversityofPennsylvania,achievedanunprecedentedcompleteeradicationofthecancerintwoofthethreechroniclymphocyticleukemia(CLL)patientsinwhomitwastried.Ithadbeenadreamofmany:theharnessingoftheimmunesystem'sferociouspowertoeliminateanadvancedmetastaticcancer.在腫瘤免疫治療的最新進(jìn)展已經(jīng)可以轉(zhuǎn)換白血病患者T細(xì)胞變成自己的癌細(xì)胞的高效特異的細(xì)胞殺手。這項(xiàng)新技術(shù)最近已測(cè)試成效顯著。成功治療的外在表現(xiàn)是顯著的，明確的。因發(fā)燒，發(fā)冷和疼痛而顫抖的癌癥患者，他們的血壓會(huì)急劇下降。在注入他們自己的工程殺傷性T細(xì)胞會(huì)使他們?cè)谒阎g輾轉(zhuǎn)反側(cè)好幾天。T細(xì)胞回輸后的內(nèi)部斗爭(zhēng)在兩至三個(gè)星期間達(dá)到高峰。裂解腫瘤細(xì)胞的負(fù)荷加大了病人的腎臟壓力并幾乎腎中毒。通過(guò)免疫治療恢復(fù)活力的免疫系統(tǒng)已經(jīng)摧毀了近1公斤的腫瘤細(xì)胞。沒(méi)有其他可供選擇的治療已經(jīng)取得了類似的治療成功。由卡爾博士和他的在美國(guó)賓夕法尼亞大學(xué)的亞伯拉罕森癌癥研究中心的同事共同執(zhí)行的新的治療方法，在試驗(yàn)的3個(gè)慢性淋巴細(xì)胞白血病(CLL)患者其中兩個(gè)實(shí)現(xiàn)了前所未有的徹底根除癌癥。它曾是許多人的夢(mèng)想：利用免疫系統(tǒng)的驚人的治理力量消除晚期轉(zhuǎn)移性癌癥。Thestunningresultswerepublishedintwosimultaneousjournalarticles[1,2],oneofthereportspresentingdatafromasinglepatient[1].Thesuccesswasbeyondexpectation.This,afterall,wasaPhaseIclinicaltrial,oneinwhichtheprimaryobjectivewastotestdifferentdosesoftheengineeredcytotoxiclymphocytes(CTL).Technically,thesuccesscouldbetracedtothefusionofextracellularandintracellulardomainsintoanew,syntheticreceptorfortheCD8+Tcells[3].In_immunotherapyjargon,thistypeofrecombinantproteiniscalledachimericantigenreceptor(CAR).Inthiscase,theextracellulardomainwasderivedfromamousemonoclonalantibodyspecificfortheCD19surfaceproteinofhumanBcells.BecauseCLLisaBcellcancer,CLLcellsexpressCD19.Theanti-CD19antibodywasreducedtoitssmallestactiveform,asingle-chainvariablefragment(scFv),andgraftedontoaTcellreceptortransmembranedomain.Ontheinsideofthecell,theconstructwasfusedtothecytoplasmicsignalingdomainsofCD137(41BB)andtheZhainofCD3(Figure1).Thisparticularcombinationoffunctionaldomainsiscreditedforachievingthespectacularsuccessofthetherapy

令人驚嘆的研究結(jié)果發(fā)表在兩個(gè)同時(shí)進(jìn)行的期刊文章，其中一個(gè)報(bào)告數(shù)據(jù)來(lái)自一個(gè)單身病人。這個(gè)成功的研究是出乎意料的。畢竟，這是第一期臨床試驗(yàn)，其主要目的之一是測(cè)試不同劑量的工程細(xì)胞毒性T細(xì)胞（CTL）。從技術(shù)上講，這次成功可以追溯到融合細(xì)胞外和細(xì)胞內(nèi)結(jié)構(gòu)域成一個(gè)新的，合成受體的CD8+T細(xì)胞。在免疫治療術(shù)語(yǔ)中，這種類型的重組蛋白被稱為嵌合抗原受體（CAR）。在這種案例中，胞外結(jié)構(gòu)域是來(lái)自特定的人類B細(xì)胞CD19表面蛋白的小鼠單克隆抗體。由于CLL是一種B細(xì)胞癌，所以白血病細(xì)胞表達(dá)CD19蛋白?？?CD19抗體被減少到最小的活性形式，單鏈可變區(qū)片段（scFv）,并且被移植到T細(xì)胞受體的跨膜結(jié)構(gòu)域。在細(xì)胞的里面，該結(jié)構(gòu)被融合到胞質(zhì)信號(hào)域CD137（41BB）和CD3Z鏈（圖1）這種功能結(jié)構(gòu)域的特定組合因獲得治療的驚人成功而得名Truncated—envTruncated-一gag/polWPRE5JLTRTruncated—envTruncated-一gag/polWPRE5JLTRpELPS19-BB-^{11556bp)3,LTR-—BovineVGHPolyA、BacterialReplicationOriginAmpRFigurel.ThebiotechnologyofchimericantigenreceptorsforcytotoxicTcell-basedcancerimmunotherapy.A.MapofpELPS19-BB-3Z，alentiviralvectorthatwasapprovedforclinicaltrials[1].TheopenreadingframeencodingthechimericfusionproteinCD19-BBZcontainsportionscodingforananti-CD19single-chainvariableregionfragment(scFv),thehingeandtransmembrane(TM)domainofCD8,andapairofsignalingendodomains(onefromCD137,theotherfromCD3Z).ThisfusionproteingeneisembeddedwithinadisabledHIV-derivedbackbonecontainingtruncated(CD137Survival1andProliferation(CD137Survival1andProliferationSignalingUrt^1AW%MIMA

gag,polandenvsequencesandthe5'and3'longterminalrepeats（LTR）.Inaddition,theconstructcontainselongationfactorla（EF-1a）codingsequences,thewoodchuckhepatitisviruspost-transcriptionalregulatoryelement（WPRE）andthebovinegrowthhormonepolyadenylation（GHpolyA）tail,aswellastheampicillinresistancegeneandabacterialreplicationorigin.Thetotalsizeoftheconstructis11,556basepairs.B.DiagramofthechimericreceptorproteinintheTcellplasmamembrane.TheextracellularantibodyrecognitiondomainislinkedviatheCD8TMdomaintothecytoplasmicsignalingdomainsofCD137andCD3Z.TheseendodomainsaccomplishtheactivationoftransducedTcellsandtheystimulateTcellsurvivalandproliferationinvivo.圖1.細(xì)胞毒性T細(xì)胞為基礎(chǔ)的腫瘤免疫治療之嵌合抗原受體的生物技術(shù)。A.pELPS19-BB-3Z圖，慢病毒載體被批準(zhǔn)用于臨床試驗(yàn)的。編碼嵌合融合蛋白CD19-BBZ的開(kāi)放閱讀框，包含抗CD19單鏈可變區(qū)片段（scFv）,CD8的鉸鏈和跨膜（TM）域，以及一對(duì)內(nèi)域信號(hào)（一個(gè)來(lái)自CD137，另一個(gè)CD3Z）的部分編碼。此融合蛋白的基因被嵌入一個(gè)包含刪除gag,pol和env序列以及5'和3'長(zhǎng)末端重復(fù)序列（LTR）的帶有缺陷型獲得性HIV脊椎。此外，該結(jié)構(gòu)包含延伸因子1a（EF-1a）的編碼序列，土撥鼠肝炎病毒轉(zhuǎn)錄后調(diào)控元件（WPRE）和牛生長(zhǎng)激素多聚腺苷酸化（生長(zhǎng)激素多聚A）尾，以及氨芐青霉素抗性基因和一個(gè)細(xì)菌的復(fù)制起點(diǎn)。該結(jié)構(gòu)的總大小是11556個(gè)堿基對(duì)。B.圖中的T細(xì)胞質(zhì)膜的嵌合受體蛋白質(zhì)。通過(guò)CD8TM域?qū)崿F(xiàn)胞質(zhì)信號(hào)領(lǐng)域的CD137和CD3Z和細(xì)胞外抗體識(shí)別域的鏈接。這些內(nèi)域完成轉(zhuǎn)導(dǎo)T細(xì)胞的激活和刺激T細(xì)胞在體內(nèi)的存活和增殖。ThegeneforthisCARwasdeliveredbylentivirustopurifiedcytotoxickillerTcellsfromeachpatient.TheHIV-1virusservedasthebackboneintheconstructionofthelentivirusvector.ThechoiceofthisvirusprovedfortunatebecausethenaturalhostforHIV-1isaTlymphocyte.Therefore,thevectorincludedsequencesthathadevolvedforreplicationandexpressioninTcells.ApreviousversionofthisvectorwasusedtotreatpatientswithchronicHIVinfections[4].TheCLLpatients'purifiedTcellsweretransducedinvitro,thenstoredforthetimerequiredtotreateachpatientwithchemotherapyandreducethenumbersofunmodifiedlymphocytes.ThisprovidedtheinvivospacetoaccommodatetheengineeredTcells.CAR基因通過(guò)慢病毒轉(zhuǎn)入純化每個(gè)病人的細(xì)胞毒性殺傷性T細(xì)胞。HIV-1病毒是慢病毒載體的主干。選擇這種病毒是幸運(yùn)的，因?yàn)镠IV-1的天然宿主是一種T淋巴細(xì)胞。因此，這個(gè)載體包含在T細(xì)胞中復(fù)制和表達(dá)的序列。這個(gè)載體的早期版本被用于治療艾滋病毒慢性感染。CLL患者的純化的T細(xì)胞在體外轉(zhuǎn)導(dǎo)，然后記錄每個(gè)化療病人治療和減少未變性淋巴細(xì)胞的數(shù)目所需要的時(shí)間。這提供了適應(yīng)工程T細(xì)胞在體內(nèi)的空間Oncethepatientswerereadyfortheexperimentaltreatment,theyreceivedbetween15Millionand1BilliontransducedCTL.TheCTLrapidlymultipliedtoapproximately1000-foldhighernumbersinvivo[2]￡artofthisexpansionmaybeattributedtothepresenceoftargetcells.ThescientistsperformingthetrialestimatedthateachengineeredCTLdestroyednearly1000leukemiacells,until,threeweeksaftertheinfusionoftheCTL,nodetectablecancercellsremained.ThepeakofCTLproliferationcorrespondedtothehighestlevelofIFN-Y,IL-6and

CXCL9incirculation[2]Jhesecytokineswereresponsibleforthepatients'highfever.OncetheCLLnumbersdroppedbelowdetectionlevels,theCTLnumbersnormalizedandtheremainingengineeredcellsacquiredthephenotypeofeffectorandmemoryTcells.Atthattime,thepatients'overallwellbeingmarkedlyimproved.一旦患者準(zhǔn)備進(jìn)行實(shí)驗(yàn)性治療，他們收到了15億至10億之間轉(zhuǎn)導(dǎo)的CTL。的CTL迅速乘以在體內(nèi)的約1000倍的更高的數(shù)字[2]。這種擴(kuò)張的部分內(nèi)容可以歸因于靶細(xì)胞的存在。進(jìn)行試驗(yàn)的科學(xué)家估計(jì)，每個(gè)工程的CTL破壞近1000個(gè)白血病細(xì)胞，直到輸注的CTL，三周后，沒(méi)有檢測(cè)到癌細(xì)胞仍然。的CTL增殖的峰值相對(duì)應(yīng)的最高水平的IFN-y，IL-6和CXCL9流通中[2]。這些細(xì)胞因子負(fù)責(zé)病人的高燒。一旦CLL數(shù)字下降到低于檢測(cè)水平，CTL數(shù)歸一化和收購(gòu)余下的工程細(xì)胞的表型效應(yīng)和記憶性T細(xì)胞。當(dāng)時(shí)，顯著提高患者的整體健康。Oneside-effectofthetherapyisBcellimmunodeficiencybecausetheengineeredCTLalsokillthepatients'non-cancerousBcells.ThiswasananticipatedconsequenceofthetherapybecausetheCTLtargetantigen,theCD19receptor,isexpressedonallmatureBcellsandBcellprecursors.ThetransferofIgGfromnormaldonors(IVIG)canreplenishthepatients'circulatingantibodiesandpartiallycompensatefortheabsenceofBcells.ThelgGinjectionswillbeperformedatmonthlyintervalstoreducetheriskofinfectionsintreatedpatients.Twoofthepatientswere,atthetimeofthereports,freeofcancerrecurrencefor6to11months[2].ThethirdshowedasustainedimprovementoftheCLL.治療的一個(gè)副作用是B細(xì)胞免疫缺陷，因?yàn)楣こ藽TL也殺死患者的非癌性的B細(xì)胞。這是一個(gè)預(yù)期的治療結(jié)果，因?yàn)镃TL的靶抗原，CD19受體被表達(dá)于所有成熟B細(xì)胞和B細(xì)胞的前體。來(lái)自正常捐助者(IVIG)的IgG轉(zhuǎn)移可以補(bǔ)充抗體循環(huán)并局部彌補(bǔ)缺乏B細(xì)胞。將進(jìn)行間隔每月一次的IgG注射來(lái)減少治療的患者中感染風(fēng)險(xiǎn)。當(dāng)時(shí)的報(bào)道，患者中有兩位在6個(gè)月至11個(gè)月無(wú)癌癥復(fù)發(fā)。第三個(gè)表現(xiàn)出CLL持續(xù)改善VariousgroupsofscientistshadattemptedtomodifyCTLtoattackcancercells.Inpioneeringwork,EshharandcollaboratorsfromtheWeizmannInstituteofScienceinRehovot(Israel)demonstratedthatCTLcanexpressarecombinantsurfacereceptorthatlinksanextracellularrecognitiondomainderivedfromanantibodytoanintracellularsignalingdomainderivedfromtheTcellreceptor[5].SuchTcellsnolongerdependonrecognitionofHLA-peptidecomplexesforspecificsignalingandTcellactivation.各種科學(xué)家團(tuán)體曾試圖修改CTL來(lái)攻擊癌細(xì)胞。在開(kāi)創(chuàng)性的工作中，Eshhar和來(lái)自以色列魏茨曼科學(xué)研究所的合作者表明，CTL表達(dá)的重組表面受體連接獲得抗體的胞外識(shí)別域和獲得T細(xì)胞受體的細(xì)胞內(nèi)信號(hào)域。這種T細(xì)胞不再依賴于特定的信號(hào)和T細(xì)胞活化的HLA-肽復(fù)合物識(shí)別。Normally,cytotoxicTcellsrecognizeforeignpeptidesinthegrooveofanHLAclassIreceptor.Thepeptidesmaybederivedfromavirusinfectingahostcell,whichdegradesaportionofthenewlyformingviralproteinsintopeptidesandloadsthemintoaclassIHLA.TherecognitionofthepeptidesasforeigntothehosttriggerstheTcelltoreleaseperforinandgranzyme,proteinsthatformporesinthetargetcellandinitiateacascadeofenzymaticreactionsleadingtothe

programmeddeathoftheinfectedcells.Inthismanner,thevirusispurgedfromthebody.通常情況下，細(xì)胞毒性T細(xì)胞在HLA類的受體的凹槽中識(shí)別外源肽。從病毒感染的宿主細(xì)胞中可以獲得這些降低部分新形成的病毒蛋白形成的多肽并加載它們?yōu)镮類HAL。從外來(lái)得到宿主的多肽的識(shí)別觸發(fā)T細(xì)胞釋放穿孔素和顆粒酶，蛋白質(zhì)，形成在目標(biāo)小區(qū)中的孔，并啟動(dòng)酶促反應(yīng)，導(dǎo)致受感染的細(xì)胞程序性死亡的級(jí)聯(lián)。在這種方式中，該病毒是從體內(nèi)清除AnanalogousreactionisthoughttooccurbetweencytotoxicTcellsandtumorcells.Theoncogenictransformationofacancercellinducestheexpressionofproteinsthatarenotexpressedinhealthytissues.TheimmunesystemcandetectthedifferencesinHLA-associatedpeptidesfromcancercells,andthecytotoxicTcells,inconsequence,releasetheircell-degradingeffectormolecules.However,inadvancedcancers,thesecytotoxicTcellsaredepletedandinefficient.Gradually,thecancercellsgaintheupperhandandgrowtonumbersthatbecomemoreandmoredifficulttocontrol.一個(gè)類似的反應(yīng)被認(rèn)為是發(fā)生在細(xì)胞毒性T細(xì)胞和腫瘤細(xì)胞之間。癌癥細(xì)胞的致癌性轉(zhuǎn)化誘導(dǎo)在健康組織中不表達(dá)的蛋白質(zhì)的表達(dá)。免疫系統(tǒng)可以檢測(cè)癌細(xì)胞中與HAL相關(guān)的多肽的差異，因此，細(xì)胞毒性T細(xì)胞釋放其降解細(xì)胞的效應(yīng)分子。然而，在晚期癌癥，這些細(xì)胞毒性T細(xì)胞被耗盡，效率不高。漸漸地，癌細(xì)胞占據(jù)上風(fēng)和成長(zhǎng)的數(shù)字變得越來(lái)越難以控制InTcellsexpressingchimericantigenreceptors,thescFvantibodyfragmentthatbindstoantigensubstitutesfortheTCRbindingtoHLApluspeptide.TheinitialsuccessofGrossetal.[5]inspired_numeroussubsequentstudiesbutobstacleshinderedeffortstoexpressrecombinantreceptorsthatcouldbindthedesiredtargetsandactivatethecytolyticfunctionsoftheTcells[6].VariousinvestigatorsdesignedandtestedsecondandthirdgenerationCARfusionproteinsbecausesingleactivationdomainCARshowedonlylimitedutilityforthestimulationofnaiveTcells[6]^Themoreadvancedreceptordesignincorporatedadditionalendodomainsthatcouldsimultaneouslyactivatemorethanonesignalingpathway.ExperimentsbyImaietal.[7]and_Finneyetal.[8]testeddualactivationdomains,includingthecombinationofCD3andCD137(4-1BB)andfoundtheaddedactivationdomainstoincreaseresponsesofengineeredCTL.Subsequently,Miloneetal.[3]demonstratedtheinvivoefficacyofthenewchimericactivationdomainsinxenogeneictumorbearingmice.TheseexperimentssetthestageforthesuccessfulclinicaltrialattheUniversityofPennsylvania[1,2].在T細(xì)胞中表達(dá)嵌合抗原受體，scFv抗體片段綁定的結(jié)合HLA加肽的TCR抗原代用品。Gross等人的初步成功鼓勵(lì)了眾多的后續(xù)研究，但可以結(jié)合預(yù)期的目標(biāo)和激活的T細(xì)胞的殺傷功能的重組受體的表達(dá)受到阻礙。各種研究人員設(shè)計(jì)和測(cè)試了第二代和第三代的CAR融合蛋白，因?yàn)閱渭せ钣駽AR僅表現(xiàn)對(duì)幼稚T細(xì)胞的刺激的有限用途。更先進(jìn)的受體設(shè)計(jì)還采用了其它內(nèi)域能同時(shí)激活多個(gè)信號(hào)轉(zhuǎn)導(dǎo)通路。Imai等人和芬尼等人的實(shí)驗(yàn)測(cè)試了雙激活域，包括CD3和CD137(4-1BB)相結(jié)合的測(cè)試，發(fā)現(xiàn)增加對(duì)工程CTL效應(yīng)的其他激活域。接著，Milone等表明在異種荷瘤小鼠的新的嵌合激活域在體內(nèi)的療效。在賓夕法尼亞大學(xué)，這些實(shí)驗(yàn)成功的臨床試驗(yàn)階段。

ThebreakthroughoccurredwiththediscoverythatthecytoplasmicdomainfromCD137(4-1BB)enabledstrongactivationoftheengineeredTcells,providedthatitwasinsertedbetweentheCD8atransmembraneregionandtheCD3Zcytoplasmicdomain[3].ThistandemconfigurationofactivatingdomainsmergedintoasinglepolypeptidechainthetaskofdeliveringtwosignalsneededfortheactivationofnaiveTcells(Figure1).Inthismanner,bindingoftheextracellularantibodydomaintoantigencouldtransmittwosignalsneededtoinducethematurationofnaiveCD8TcellsintoeffectorTcells.Thecellsexpressingthetandemchimericantigenreceptorsreceivedstrongsignalstoproliferateanddifferentiateintopotentcancer-destroyingkillerTcells[1].這一突破來(lái)自CD137(4-1BB)的胞質(zhì)域中使工程T細(xì)胞增強(qiáng)活性的發(fā)現(xiàn)，條件是它被插入CD8a跨膜區(qū)和CD3Z胞質(zhì)域之間的。這種串聯(lián)結(jié)構(gòu)的激活提供幼稚T細(xì)胞的活化(圖1)所需的兩個(gè)信號(hào)的任務(wù)合并成一個(gè)單一的多肽鏈的域。以這種方式，對(duì)抗原的抗體的胞外域綁定可以傳輸需要兩個(gè)信號(hào)誘導(dǎo)幼稚CD8+T細(xì)胞的成熟成效應(yīng)T細(xì)胞。串聯(lián)嵌合抗原受體的細(xì)胞表達(dá)獲得強(qiáng)烈的信號(hào)進(jìn)行增殖并分化成強(qiáng)力摧毀癌癥的殺傷性T細(xì)胞。Clearly,thenewresearchwillstimulateeffortstoextendthisapproachtootherrefractorycancers.Still,caveatsremain.Thenumbersofpatientstreateduptonowremainverysmallandthetimeelapsedsincethetreatmentisshort,thussuccesscouldstillremainelusive.However,hopesthatapromisingnewtherapyiswithinreachincreasewitheverypassingday.Inall,morethan25clinicaltrialscurrentlyexploretheuseofchimericTcellreceptorsinvariousformsofcancer[9].Itmight_befeasibletoextendtheCLLtherapy[1,2]tootherBlymphocyticneoplasms,assimilarlyengineeredCTLshouldbecapableofattackinganyCD19-positivecancercells.Yetimportanthurdlesremain:Itmayprovedifficulttodevelopantibodieswithexclusivespecificityforcancercellsthatdonotcross-reactwithhealthytissues.Anycross-reactivitymayleadtoautoimmunitythatcoulddamagevitalorgans.Furthermore,theviolentside-effectsassociatedwiththeclearanceofcancercellsmakeitdesirabletofindwaystoregulatetherateofCTLactivation.Forexample,therearewaysinwhicha"safetyswitch"maybeincorporatedintoengineeredTcellsthatcoulddeactivatethemincasethattheCTLtherapyexposespatientstounacceptablecomplications[10].ThesuccessofthephaseItrialwithtandemendodomainCARsdeliveredbylentivirus[1.2]willsurelyenergizethesearchforadditionalrecombinantimmunetherapiesforadvancedcancer.顯然，新的研究將刺激拓展這種方法到其他難治性癌癥的努力。不過(guò)，注意事項(xiàng)依然存在。到現(xiàn)在治好的患者人數(shù)仍然非常少并且療程短，因此成功可能仍然是難以捉摸的。然而，有前途的新療法的希望是日趨增加。超過(guò)25項(xiàng)臨床試驗(yàn)，目前正在探索各種形式的癌癥。它可能是可行的，延長(zhǎng)CLL的治療到其他B淋巴細(xì)胞腫瘤，像類似的工程CTL應(yīng)該是能夠攻擊任何CD19陽(yáng)性癌細(xì)胞的。然而，重要的障礙依然存在：它可能難以對(duì)不與健康組織發(fā)生交叉反應(yīng)的腫瘤細(xì)胞產(chǎn)生專一特異性抗體。任何交叉反應(yīng)可能會(huì)導(dǎo)致自身免疫性疾病，可能會(huì)損壞重要器官。此外，與癌細(xì)胞的清除的嚴(yán)重副作用使得必須能找到方法來(lái)調(diào)節(jié)CTL的激活率。例如，有一些方法，其中一個(gè)能禁止“安全開(kāi)關(guān)”成為工程T細(xì)胞一部分以防CTL治療使患者遭受不可接受的并發(fā)癥。通過(guò)慢病毒傳遞的帶有串聯(lián)內(nèi)域CARs的I期臨床試驗(yàn)的成功無(wú)疑必將激勵(lì)尋找對(duì)晚期癌癥其他的重組免疫療

CompetinginterestsTheauthordeclaresthathehasnocompetinginterests.AcknowledgementsTheauthoracknowledgestheexpertassistanceofDafneSolera,Ph.D.,ExecutiveEditorofBMCBiotechnology,withessentialadjustmentsinstyleandcontent.ThetechnicaldiagramofMr.TimHiggins,seniorillustrator,isacknowledged.ReferencesPorterD丄evineBL,KalosM,BaggA,JuneCH:Chimericantigenreceptor-modifiedTcellsinchroniclymphoidleukemia.NEnglJMed2011,365:725-733.PubMedAbstract|PublisherFullTextKalosM,LevineBL,PorterDL,KatzS,GruppSA,BaggA,JuneCH:Tcellswithchimericantigenreceptorshavepotentantitumoreffectsandcanestablishmemoryinpatientswithadvancedleukemia.SciTranslMed2011,3:95ra73.PubMedAbstract|PublisherFullTextMiloneMC,FishJD,CarpenitoC,CarrollRG,BinderGK,TeacheyD,SamantaM,LakhalM,GlossB,Danet-Des