学科分类
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18 个结果
  • 简介:Mammaliancelltotipotencyisasubjectthathasfascinatedscientistsforgenerations.AlonglastingquestionwhethersomeofthesomaticcellsretainstotipotencywasansweredbythecloningofDollyattheendofthe20thcentury.Thedawnofthe218thasbroughtforwardgreatexpectationsinharnessingthepoweroftotipotentcyinmedicine.Throughstemcellbiology,itispossibletogenerateanypartsofthehumanbodybystemcellengineering.Considerableresourceswillbedevotedtoharnesstheuntappedpotentialsofstemcellsintheforeseeablefuturewhichmaytransformmedicineasweknowtoday.Atthemolecularlevel,totipotencyhasbeenlinkedtoasingulartranscriptionfactoranditsexpressionappearstodefinewhetheracellshouldbetotipotent.NamedOct4,itcanactivateorrepresstheexpressionofvariousgenes.Curiously,verylittleisknownaboutOct4beyonditsabilitytoregulategeneexpression.ThemechanismbywhichOct4specifiestotipotencyremainsentirelyunresolved.Inthisreview,wesummarizerethestructureandfunctionofOct4andaddresstoOct4functioninmaintainingtotipotencyorpluripotencyofembryonicstemcels.

  • 标签: 干细胞 全能性 复制 翻译 蛋白因子
  • 简介:InteractionbetweencytotoxicTlymphocyte-associatedantigen-4(CTLA4,CD152)andB7molecules(B7-1andB7-2)isofimportanceinthecellulareventsoflymphocyte,includingantigen-specificT-cellactivationandinductionofautoreactiveT-cell.WedescribehaerethefirstintroductionofamurinesolubleCTLA4gene,CTLA4Ig,toMm1cells,amacrophagiccellline.CTLA4IgwassuccessfullyexpressedonMm1cellsandtheexpressedCTLA4IgwasfoundtobefunctionallyactiveintheirbindingtoB7moleculesbyflowcytometryandimmunofluorescencestudies.ThebiologicalactivityofCTLA4IgfromthetransfectedMm1cellswasstudiedandshowedinhibitoryactivityonmixedlymphocyteculture.AhighCTLA4Igproducingmacrophagiccelllinewasobtained.AsMm1cellswereregardedasdifficultforgenetransfectionandtherehassofarbeennoreportonexpressionofCTLA4IggeneonMm1cells,theseresultssuggestedthattheCELA4IgexpressingMm1cellscouldbeusefulforanalysisofCTLA4andB8moleculeinteractioninbothmacrophageandT-cell.

  • 标签: T淋巴细胞相关抗原4 细胞毒 可溶型 巨噬细胞 生物学活性 表达
  • 简介:Trichosanthin(TCS)isapotentallergentomice.Accordingtoourpreviousexperiments,itcouldbringouttheIgEresponsetoovabumin(OVA)ifTCSwasgivenonedaybeforeOVAimmunization,whileOVAalonecouldnotinduceIgEtoit.Inthiswork,thekineticsofinterleukin4(IL-4)andinterferonγ(IFN-γ)geneexpressioninthemesentericlymphnode(MLN)ofTCS-immunizedmicewasinvestigatedusingasemi-quantitativeRT-PCRmethod.ItindicatedthatTCSinducedsignificantIL-4geneexpressionandthepeaksofIL4geneexpressionwereondayoneafterTCSimmunizationinbothprimaryandsecondaryresponse.Incontrast,theIFN-γgeneexpressionwassuppressed.Furthermor,theIL-4geneexpressioninthesecondaryresponsewaslowerthanthatintheprimaryresponse.ThusthepresenceofIgEmemoryBcellswerestudied.ResultsshowedthattheamountofmatureIgEmRNAarosesignificantlyandrapidlyonedayafterTCSrestimulation,whileintheMLNofthemiceprimed30daysbeforeandwithoutboost,itwasalmostasthesameamountoftheunimmunizedcontrol.ThesefindingssuggesttheexistenceoftheIgEmemoryBcellsinthemiceaftertheprimaryTCSimmunization.

  • 标签: IL-4 IFN-γ Trichosansin 小鼠 免疫反应 基因表达
  • 简介:Asimplemethodtocreateachromosome-specificDNAlibrqaryofrice,includingmicrodissection,amplification,charterizationandcloning,isdescribed.Ricechromosome4fromametaphasecellhasbeenisolatedandamplifiedbytheLinkerAdapterPCR(LA-PCR).ThePCRproductswerelabeledasprobeswithDIG-11-dUTPusingtherandomprimingmethod.SouthernblotanalysiswithricegenomicDNAandspecificRFLPmarkersdemonstratedthatthePCRproductswerederivedfromricechromosome4.Alargelibrarycomprisingover100,000recombinantplasmidmicroclonesfromricechromosome4wasconstructed.Colonyhybridizationshowedthat58%oftheclonescontainedsingleorlow-copysequencesand42%containedrepetitivesequences.ThesizeofinsertsgeneratedbyPCRrangedfrom140bpto500bp.ThismethodwillfacilitatecloningofthespecificchromosomeDNAmarkersandimportantgenesofrice.

  • 标签: 水稻 第4号染色体 DNA文库 LA-PCR 显微解剖
  • 简介:Interleukin-4isacytokineproducedbyactivatedTcells,mastcells,andbasophilsthatelicitsmanyimportantbiologicalresponses[1](seeTab1).TheseresponsesrangefromtheregulationofhelperTcelldifferentiation[2]andtheproductionofIgE[3]totheregulationoftheadhesivepropertiesofendothelialcellsviaVCAM-1[4],Inkeepingwiththesediversebiologicaleffects,high-affinitybindingsitesforIL-4(Kd20to300pM)havebeendetectedonmanyhematopoieticandnon-hematopoieticcelltypesatlevelsrangingfrom50to5000sitespercell[5].ThisreviewwillfocusonthediscretesignaltransductionpathwaysactivatedbytheIL-4recxeptorandthecoordinationoftheseindividualpathwaysintheregulationofafinalbiologicaloutcome.

  • 标签: 白介素-4 基因表达 生长 细胞存活 调节 生物学作用
  • 简介:Perforin是主要从事调停形成毛孔蛋白质目标T房间死亡并且被细胞毒素T淋巴细胞(CTL)和自然漂亮房间采用。然而,它是否也在常规CD4+T房间功能起一作用,仍然保持不清楚。这里,我们报导那在perforin缺乏(PKO)老鼠,CD4+T房间是响应Thyperproliferative房间受体(TCR)刺激。hyperproliferation这个特征被改进在房间分割并且在IL-2分泌物伴随。看起来,perforin缺乏不在胸腺怒气和淋巴节点影响T房间开发。在vivo,perforin缺乏导致增加抗原特定T房间增长和抗体生产。而且,PKO老鼠更产生试验性自体免疫眼色素层炎。探讨分子机制,我们发现在TCR刺激以后,从PKO老鼠CD4+T房间显示增加细胞内部钙流动并且随后提高抄写因素NFAT1激活。我们结果显示perforin在由影响TCR依赖Ca2+发信号调整CD4+T房间激活和有免疫力反应起一否定作用。

  • 标签: T细胞活化 CD4 钙信号 穿孔 细胞毒性T淋巴细胞 T细胞受体
  • 简介:在脂肪和肌肉房间,刺激胰岛素葡萄糖举起被葡萄糖transporter主要调停4(GLUT4),哪个到响应胰岛素刺激房间表面的从细胞内部分隔空间translocates。AS160是Akt底层之一并且在调整胰岛素GLUT4translocation起重要作用。在这研究,(RUVBL2)象RuvB一样蛋白质2用与集体spectrometry相结合哺乳动物双人脚踏车亲密关系纯化(龙头)作为新AS160有约束力蛋白质被识别。在3T3-L1adipocytes,RUVBL2高度被表示并且在cytosol主要是分布式。在adipocytesRUVBL2弄空通过减少刺激胰岛素AS160phosphorylation禁止刺激胰岛素GLUT4translocation和葡萄糖举起。然而,人RUVBL2介绍能颠倒这禁止效果。这些数据建议RUVBL2通过它和AS160相互作用在刺激胰岛素GLUT4translocation起一重要作用。

  • 标签: 结合蛋白 转位 葡萄糖转运体 串联亲和纯化 脂肪细胞 肌肉细胞
  • 简介:POU抄写因素OCT4不仅在维持pluripotent和房间而且幕作为通过基因剂量房间命运决定因素完成胚胎茎(ES)自我更新状态起一必要作用。然而,控制细胞内部OCT4蛋白质水平分子机制留下逃犯。这里,我们报导那人WWP2,E3ubiquitin(Ub)蛋白质ligase,通过它WW领域明确地与OCT4交往并且在vitro并且在vivo提高OCT4Ub修正。我们首先证明在人ES房间内长OCT4能被Ubpost-translationally修改。而且,我们发现WWP2以一种剂量依赖者方式,和WWP2活跃地点半胱氨酸残余通过26Sproteasome支持了OCT4降级在OCT4上为它活动和解朊效果被要求。显著地,我们当WWP2表示是由特定RNA干扰(RNAi)downregulated时,内长OCT4蛋白质水平显著地被提高数据表演,建议那WWP2是为在人ES房间维持合适OCT4蛋白质水平重要管理者。而且,北污点分析证明WWP2抄本在多样的人织物/器官是广泛地在场并且高度在无差别的人ES房间表示了。然而,它表示水平快速在区分的人ES房间以后被减少,显示WWP2表示力量发展地被调整。我们调查结果证明WWP2是在人ES房间OCT4蛋白质水平重要管理者。

  • 标签: 人类胚胎干细胞 转录因子 退化 蛋白质水平 Northern 半胱氨酸残基
  • 简介:IL-16isaligandandchemotacticfactorforCD4+Tcells.IL-16inhibitstheCD3mediatedlymphocyteactivationandproliferation.TheeffectsofIL-16onthetargetcellsaredependentonthecelltype,thepresenceofco-activatorsetc.TounderstandtheregulationfunctionandmechanismofIL-16ontargetcells,weuseda130a.a.recombinantIL-16tostudyitseffectsonthegrowthofJurkatTleukemiacellsinvitro.WefoundthattherIL-16stimulatedtheproliferationofJurkatcellsatlowdose(10^-9M),butinhibitedthegrowthofthecellsathigherconcentration(10^-5M).Resultsshowedthat10^-5MofrIL-16treatmentinducedanenhancedapoptosisinJurkatcells.ThetreatmentblockedtheexpressionofFasL,butup-regulatedthec-mycandBidexpressioninthecells.Pre-treatmentofPKCinhibitororMEK1inhibitormarkedlyincreasedordecreasedtherIL-16inducedgrowth-inhibitingeffectsonJurkatcells,respectively.TheresultssuggestedthattherIL-16mightbearegulatorforthegrowthorapoptosisofJurkatcellsatadose-dependentmanner.Thegrowth-inhibitingeffectsofrIL-16mightbeFas/FasLindependent,but,associatedwiththeactivationofPKC,up-regulatedexpressionofc-MycandBid,andtheparticipationoftheERKsignalpathwayinJurkatcells.

  • 标签: IL-16 CD4+T细胞 趋化因子 信号传递 生长调节
  • 简介:Glatiramer醋酸盐(GA)是过去常对待多重硬化immunomodulatory肽药。它处理效果被扩展了到象uveoretinitis,煽动性肠疾病,接枝拒绝和肝纤维变性那样另外自体免疫条件。这里,我们报导GA在在cyclophosphamide(CY)改变糖尿病临床功课是有效加强非肥胖糖尿病患者(CY点头)老鼠。有显著地减少GA治疗在老鼠和改善insulitis糖尿病率,它与增加CD4+CD25+Foxp3+T房间反应与一致在对待老鼠。GA处理导致了抄写因素Foxp3增加表示并且在vivo并且在vitro提高了interleukin-4(IL-4)生产。Foxp3起来规定上GA效果通过IL-4部分被调停,是明显。IL-4被发现维持Foxp3表示和CD4+CD25+规章T房间(Tregs)规章功能。这研究提供GA通过Tregs正式就职为类型1糖尿病有处理潜力,那增加IL-4生产为提高Treg在GA处理功能部分负责新证据。

  • 标签: 调节性T细胞 T细胞反应 糖尿病 CD4 诱导 醋酸
  • 简介:Glucosetransporter4(GLUT4)isresponsibleforinsulin-stimulatedglucosetransportingintotheinsulin-sensitivefatandmusclecells.ThedynamicsofGLUT4storagevesicles(GSVs)remainstobeexploredanditisunclearhowGSVsarearrangedbasedontheirmobility.Weexaminedthisissuein3T3-L1cellsviainvestigatingthethree-dimensionalmobilityofsingleGSVlabeledwithEGFP-fusedGLUT4.Athinlayerofcytosolrightadjacenttotheplasmamembranewasilluminatedandsuccessivelyimagedat5Hzunderatotalinternalreflectionfluorescencemicroscopewithapenetrationdepthof136nm.Employingsingleparticletracking,thethree-dimensionalsubpixeldisplacementofsingleGSVwastrackedataspatialprecisionof22nm.Boththemeansquaredisplacementandthediffusioncoefficientwerecalculatedforeachvesicle.Trackingresultsrevealedthatvesiclesmovedasifrestrictedwithinacagethathasameanradiusof160nm,suggestingthepresenceofsomeintracellulartetheringmatrix.ByconstructingthehistogramofthediffusioncoefficientsofGSVs,weobservedasmoothdistributioninsteadoftheexistenceofdistinctgroups.TheresultindicatesthatGSVsaredynamicallyretainedinacontinuousandwiderangeofmobilityratherthanintoseparateclasses.

  • 标签: 胰岛素 葡萄糖载体4 葡萄糖载体4贮藏囊泡 3T3-L1细胞 全内反射 荧光显微法