TGF-b-induced Foxp3 inhibits TH17 cell differentiation by an

Th17

LETTERS

Vol453|8May2008|doi:10.1038/nature06878本页已使用福昕阅读器进行编辑。福昕软件（Ｃ）２００５－２００８，版权所有，仅供试用。

TGF-b-inducedFoxp3inhibitsTH17cell

differentiationbyantagonizingRORctfunction

LiangZhou1,JaredE.Lopes3,4,MarkM.W.Chong1,IvayloI.Ivanov1,RoyMin1,2,GabrielD.Victora1,YueleiShen1,JianguangDu3,4,YuriP.Rubtsov5,AlexanderY.Rudensky5,StevenF.Ziegler3,4&DanR.Littman1,2

ThelpercellsthatproduceIL-17(TH17cells)promoteautoimmu-nityinmiceandhavebeenimplicatedinthepathogenesisofhumaninflammatorydiseases.Atmucosalsurfaces,TH17cellsarethoughttoprotectthehostfrominfection,whereasregulatoryT(Treg)cellscontrolimmuneresponsesandinflammationtrig-geredbytheresidentmicroflora1–5.Differentiationofbothcelltypesrequirestransforminggrowthfactor-b(TGF-b),butdependsondistincttranscriptionfactors:RORct(encodedbyRorc(ct))forTH17cellsandFoxp3forTregcells6–8.HowTGF-bregulatesthedifferentiationofTcellswithopposingactivitieshasbeenperplex-ing.Herewedemonstratethat,togetherwithpro-inflammatorythesmallintestinallaminapropriaofthemouse.Invitro,TGF-b-inducedFoxp3inhibitsRORctfunction,atleastinpartthroughtheirinteraction.Accordingly,laminapropriaTcellsthatco-expressbothtranscriptionfactorsproducelessIL-17(alsoknownasIL-17a)thanthosethatexpressRORctalone.IL-6,IL-21andIL-23relieveFoxp3-mediatedinhibitionofRORct,therebypromotingTH17celldifferentiation.Therefore,thedecisionofantigen-stimulatedcellstodifferentiateintoeitherTH17orTregcellsdependsonthecytokine-regulatedbalanceofRORctandFoxp3.

WhenTlymphocytesareexposedtomicrobialantigens,theyacquirediverseeffectorfunctionsdependingonwhichcytokines

Figure1|Co-expressionofFoxp3andRORctinvitroandinvivo.a,NaiveCD41Tcellswerestimulatedwithanti-T-cellreceptor(TCR)and5ngml21TGF-bfor48h,andwerestainedwith4,6-diamidino-2-phenylindole(DAPI;bluenuclearstain;UVchannel),anti-RORc(red;Cy3channel)andanti-Foxp3(green;Cy5channel)monoclonalantibodies.Allpanelsareofthesamesection.Thebottom-leftimageshowsFoxp3-only,bottom-rightshowsRORc-only,top-rightshowsoverlayofFoxp3andRORcchannels,andtop-leftshowsoverlayofallthreechannels.Foxp3,RORctanddouble-expressing(DP)cellsareindicatedwithcolouredarrows.b,AnalysisofFoxp31RORct1cellsfromthesmallintestinallaminapropria.CD41GFPintandCD41GFP2cellsweresortedfromlaminapropriaofRorc(ct)1/gfpandRorc(ct)gfp/gfpmice,andFoxp3expressionwasexaminedbyintracellularstaining.Resultsarerepresentativeofthreeexperiments.Thenumbersindicatethepercentageoftotalcellsineachgate.c,ExpressionofIL-17inFoxp31RORct1andFoxp32RORct1Tcellsfromsmallintestine.Foxp3andIL-17expressionwasexaminedbyintracellularstainingofsortedTCRb1CD41GFPintcellsfromthelaminapropriaofRorc(ct)1/gfpmice.

1

areproducedbyactivatedcellsoftheinnateimmunesystem12.Differentiationofpro-inflammatoryTH17cellsrequiresthepresenceofIL-23,whichisproducedbyactivateddendriticcells13–15.Invitro,however,TH17celldifferentiationisindependentofIL-23andisinducedbyTGF-bplusIL-6orIL-21(refs6,9–11).BothinvitroandinvivodifferentiationoftheTH17celllineagerequiretheupre-gulationoftheorphannuclearreceptorRORct7.TGF-bisalsorequiredtorestraininflammatoryautoimmuneresponses16.AmongitsnumerouspropertiesisitsabilitytoinduceexpressionofFoxp3innaiveantigen-stimulatedTcells,endowingthecellswithregulatoryorsuppressorfunction8.Thus,TGF-bcaninducebothregulatoryandpro-inflammatoryTcells,dependingonwhetherpro-inflammatory

a

Foxp3-only RORγt-only DP

b

gfp/+

Foxp3 RORγt DAPI

c

+int

1010Rorc(gt)gfp/+

+

1010101010–

10101010Foxp3

101010IL-17

10+–

1010+

1010101010–

10101010Foxp3

101010IL-17

10CD4CD4CD4

TheKimmelCenterforBiologyandMedicineoftheSkirballInstitute,and2HowardHughesMedicalInstitute,DepartmentsofMicrobiologyandPathology,NewYorkUniversity

SchoolofMedicine,NewYork,NewYork10016,USA.3ImmunologyProgramBenaroyaResearchInstituteSeattle,Washington98101,USA.4DepartmentofImmunologyUniversityofWashingtonSchoolofMedicineSeattle,and5HowardHughesMedicalInstitute,DepartmentofImmunology,UniversityofWashingtonSeattle,Washington98195,USA.

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cytokinessuchasIL-6and,potentially,IL-23arepresent11,17.Treatmentofantigen-receptor-stimulatedTcellswithTGF-baloneinducesexpressionofbothFoxp3andRORct,butnotofIL-17(refs7,11).Aftersuchtreatment,asignificantproportionofcellsco-expressedthetwotranscriptionfactors(Fig.1aandSupplementaryFig.1a).Todeterminewhetherco-expressionalsooccursinvivo,weexaminedCD41TcellsfromthesmallintestinallaminapropriaofheterozygousRORct–GFP(greenfluorescentprotein)knock-inmice,inwhichIL-17isproducedbyTCR1GFPintlymphocytes7.Foxp3wasexpressedinabout10%ofsortedGFPint(RORct1)cells(Fig.1bandSupplementaryFig.1b).Inaddition,Foxp3wasexpressedinapproxi-mately17–20%ofGFP2laminapropriaCD41Tcells,consistentwiththerelativelylargeproportionofTregcellsintheintestine.

Wenextperformedafate-mappinganalysistodeterminethepro-portionofIL-171smallintestinalTcellsthathadexpressedFoxp3duringtheirontogeny.MiceexpressingCrerecombinaseundertheregulationoftheFoxp3locus(Y.P.R.etal.,submitted)werecrossedwithRosa26-stop–YFPreportermice18,andfemaleprogeny(Rosa26stop–YFP/1;Foxp3cre/1)wereanalysedforexpressionofyellowfluorescentprotein(YFP).WheninactivationofX-linkedFoxp3wastakenintoaccount,wefoundthatapproximately15%ofIL-172cellsand25%ofIL-171cellshadexpressedCreatsomestageofdevelop-ment(SupplementaryFig.2).TheformerrepresentFoxp31Tregcells,whereasthelatteraretheminimalproportionofTH17cellsthathadexpressedFoxp3atsomestageoftheirdifferentiation.ThesedatasuggestthatFoxp31TcellscandifferentiateintoTH17cellsinvivointhepresenceofpro-inflammatorycytokines.

ExaminationofIL-17expressioninheterozygousRORct–GFPknock-inmicerevealedthatRORct1Foxp31laminapropriaTcells

a

producedmuchlessIL-17thanRORctFoxp3cells,suggestingthatFoxp3mayinterferewiththeabilityofRORcttoinduc …… 此处隐藏：27952字，全部文档内容请下载后查看。喜欢就下载吧 ……