简介:<正>Asoneofthemostcharacterizedcytokines,interleukin3(IL-3)iswellknownforitssurvivaleffectonbothprogenitorsandmaturebloodcells.Althoughwiththeextensivestudies,thesignalingpathwaysandunderlyingmechanismleadingtosurvivalresponsesofIL-3stillarenotcompletelyunderstood.Recently,anapoptoticgeneticpathwayofC.eleganswassuggestedtobeevolutionallyconservedinthatcontrolsthecytokine-dependentanti-apoptoticresponsesinmammalianhematopoieticcelllineages.Amongthispathway,Ces-2isknowntobethefirstdeathspecificationgeneintheC.eleganspathwayandencodesabZIPfamilytranscriptionalfactorthatsharesthesameDNArecognitionsequencewithanoncoprotein,
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.
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.
简介:ThesplicingofmanyalternativeexonsintheprecursormessengerRNA(pre-mRNA)isregulatedbyextracellularfactorsbuttheunderlyingmolecularbasesremainunclear.HerewereportthedifferentialregulationofBcl-xpre-mRNAsplicingbyextracellularfactorsandtheirdistinctrequirementsforpre-mRNAelements.InK562leukemiacells,treatmentwithinterleukin-6(IL-6)orgranulocyte-macrophagecolonystimulatingfactor(GM-CSF)reducedtheproportionoftheBcl-xLvariantmRNAwhiletreatmentwith12-O-tetradecanoylphorbol13-acetate(TPA)hadnoeffect.InU251gliomacells,however,TPAefficientlyincreasedtheBcl-xLlevel.Theseregulationswerealsoseenforatransfectedsplicingreportermini-gene.Furtheranalysesofdeletionmutantsindicatethatnucleotides1-176ofthedownstreamintronarerequiredfortheIL-6effect,whereasadditionalnucleotides177-284areessentialfortheGM-CSFeffect.AsfortheTPAeffect,onlynucleotides1-76arerequiredinthedownstreamintron.Thus,IL-6,GM-CSFandTPAdifferentiallyregulateBcl-xsplicingandrequirespecificintronicpre-mRNAsequencesfortheirrespectiveeffects.
简介:Thebindingofnuclearproteinspreparedfrommouseerythroidtissueindifferentdevelopmentalstagestothe5'-flankingregulatoryelementsofhumanβ-globingene,twonegativecontrolregions(NCR1,-610to-490bp;NCR2,-338,to-233bp),wasidentified.TwostagespecificproteinfactorscorrespondingtoembryonicandfetalstageswerefoundtobecapableofbindingtoNCR2.Thesedataprovidedevidencethatthecisactingelementsofthe5'-flankingregionmightbeinvolvedinthedevelopmentalcontrolofβ-globingeneandNCR2mightberesponsibleinartforthesilenceofβ-glolbingeneintheembryonicandfetalstages.
简介:MicroRNAs(miRNA)指导在基因表示的一个重要角色在植物为到环境条件的发展进程和回答要求了的顺序特定的posttranscriptional基因silencing玩。然而,很少对transcriptional和miRNA表示的posttranscriptional规定被知道。Histoneacetylation在染色质改变起一个重要作用并且为基因激活被要求。由在Arabidopsis的异种分析miRNAs和相应主要miRNAs的子集的累积,我们显示出那histoneacetyltransferaseGCN5(一般控制非镇压的protein5)在miRNA上有一般压抑的效果生产,当它为一个子集的表示被要求时(例如压力可诱导)MIRNA基因。在miRNA生产的GCN5的一般否定功能多半通过象DICERLIKE1(DCL1)那样的miRNA机械基因的间接压抑被完成,有锯齿(SE),偏下性的LEAVES1(HYL1)和ARGONAUTE1(AGO1)。染色质immunoprecipitation试金表明GCN5指向到MIRNA基因的一个子集并且为在这些loci的histoneH3离氨酸14的acetylation被要求。而且,由trichostatin的histonedeacetylation的抑制一个处理或在histonedeacetylase,基因异种损害了某些miRNAs的累积。这些数据一起建议ArabidopsisGCN5在transcriptional和posttranscriptional层次防碍miRNA小径,histoneacetylation/deacetylation是涉及miRNA的规定的epigenetic机制生产。
简介:Xenopusorganizerspecificgenenogginpossessesnearlyallthecharacteresticpropertiesoftheactionoforganizertospecifytheembryonicbodyacis.Toanalyzehowthematernalinheritedfactorscontrolitsexpressionpattern,weclonedthe5'regulatoryregionofnoggingene.The1.5kbupstreamsequensecoulddirectreportergenetoexpressinvivoanddatafromdeletionanalysisindicatedthata229basepairfragmetisessentialforactivatingnogginexpression.WefurtherdemonstratedthattheresponseelementswithinthisregulatoryregionwereindeedunderthecontrolofgrowthfactoractivinandWntsignalingpathwaycomponents.
简介:流行性感冒的所有已知的子类型A病毒在野水鸟被维持,这些病毒的自然水库。流行性感冒A病毒被孤立从许多有改变病态和死亡率的动物种类。更重要地,流行性感冒A病毒与潜在地致命的结果在人引起呼吸疾病。在人的本地或全球的爆发被过量住院和死亡典型地描绘。在1997,H5N1子类型的高度病原的鸟的流行性感冒病毒在传给人的香港出现了,导致由鸟的流行性感冒病毒感染的人的死亡的首先记录的盒子。在越南,印度尼西亚,和泰国在家禽在2003年7月开始的新爆发,和高度病原的鸟的H5N1流行性感冒病毒后来在整个亚洲并且进欧洲和非洲传播了。这些病毒继续与高死亡率感染人并且引起隐约可见的世界范围的担心流行。而且,H5N1病毒爆发在整个亚洲在家禽工业上有破坏效果。因为H5N1病毒爆发看起来从南部的中国发源,我们这里在中国检验H5N1流行性感冒病毒,与他们的生物性质上的一个重音。
简介:cAMPmediatedsignalingmayplayasuppressiveroleinimmuneresponse.WepreviouslyfoundthatthecAMP-elevators(CTxand8-Br-cAMP)inhibitedIL-12,IL-la,IL-6geneexpression,butincreasedthetranscriptionallevelsofIL-10andIL-1RainLPS-treatedmurineperitonealmacrophages.ThepresentstudyexaminedapossiblemolecularmechanisminvolvedincAMPelevators-inducedinhibitionofIL-12p40expressioninresponsetoLPS.OurdatademonstratedthatcAMPelevatorsdownregulatedIL-12p40mRNAexpressionandIL-12pT0productioninmurineperitonealmacrophages.SubsequentstudiesrevealedthatcAMP-elevatorsblockedphosphorylationofp38MAPK,butdidnotaffecttheactivityofNF-κBbindingtoIL-12promoter(-136/-112).ThisisthefirstreportthatcAMPelevatorsinhibitLPS-inducedIL-12productionbyamechanismthatisassociated,atleastinpart,withp38-dependentinhibitionbycAMPsignalingpathways.
简介:Hybridoma房间在抗体生产率追随者暴露显示增加到张力亢进的条件。然而,内在的机制很好没被理解。在现在的学习,我们假设激活的T房间的原子因素5(NFAT5)/tonicityenhancer绑定蛋白质(TonEBP)工作增加hybridomacells的抗体生产率。NFAT5是osmosensitive哺乳动物的抄写因素。然而,它在没在张力亢进的周围被洗的各种各样的器官的无所不在的表示建议NFAT5可以也在等渗的条件下面调整细胞生长和功能。在这研究,我们由西方的污点分析在hybridoma房间检验了表示ofNFAT5,并且发现它在张力亢进的媒介显著地增加了。为了推进,在hybridoma房间定义NFAT5的功能,RNA干扰技术习惯于down在SGB-8房间(一根hybridoma房间线)调整NFAT5的表示。在等渗的媒介,hybridoma房间的抗体生产率被NFAT5while的down规定减少细胞增殖没被影响。这里介绍的结果表明那NFAT5不仅在hybridoma房间在渗透的压力反应小径起一个重要作用而且为最佳的抗体生产率是必要的。
简介:Thenuclearmatrixattachmentregions(MARs)andthebindingnuclearmatrixproteinsinthe5'-flankingcisactingelementsofthehumanε-globingenehavebeenexamined.UsinginvitroDNA-matrixbindingassay,ithasbeenshownthatthepositivestage-specificregulatoryelement(ε-PREII,-446bp--419bp)upstreamofthisgenecouldspecificallyassociatewiththenuclearmatrixfromK562cells,indicatingthatε-PREIImaybeanerythroidspecificfacultativeMAR.IngelmobilityshiftassayandSouthwesternblottingassay,anerythroid-specificnuclearmatrixprotein(ε-NMPk)inK562cellshasbeenrevealedtobindtothispositiveregulatoryelement(ε-PREII).Furthermore,wedemonstratedthatthesilencer(-392bp--177bp)upstreamofthehumanε-globingenecouldassociatewiththenuclearmatricesfromK562,HELandRajicells.Inaddition,thenuclearmatrixproteinspreparedfromthesethreecelllinescouldalsobindtothissilencer,suggestingthatthissilencerelementmightbeaconstitutivenuclearmatrixattachmentregion(constitutiveMAR).Ourresultsdemonstratedthatthenuclearmatrixandnuclearmatrixproteinsmightplayanimportantroleintheregulationofthehumanε-globingeneexpression.
简介:Thenon-classicalHLAclassIantigenHLA-GisanimmunemodulatorwhichinhibitsthefunctionsofTcells,NKcells,andtheDendriticcells(DC).Asaresult,HLA-Gexpressioninmalignantcellsmayprovidethemwithamechanismtoescapetheimmunesurveillance.Inmelanoma,HLA-Gantigenexpressionhasbeenfoundin30%ofsurgicallyremovedlesionsbutinlessthan1%ofestablishedcelllines.OnepossiblemechanismunderlyingthedifferentialHLAGexpressioninvivoandinvitroisthattheHLA-Ggeneisepigeneticallyrepressedinmelanomacellsinvitro.Totestthishypothesis,wetreatedtheHLA-GnegativemelanomacelllineOCM-1AwiththeDNAmethyltransferaseinhibitor5-aza-2'-deoxycytidine(5-AC)andanalyzedwhetherHLA-Gexpressioncanberestored.OurdatastronglysuggestthatHLA-GissilencedasaresultofCpGhypermethylationwithina5'regulatoryregionencompassing220bpupstreamofthestartcodon.Aftertreatment,HLA-GmRNAexpressionwasdramaticallyincreased.WesternblotandflowcytometryshowedthatHLA-Gproteinwasinduced.Interestingly,HLA-Gcellsurfaceexpressiononthe5-ACtreatedOCM-1AcellsismuchlessthanthatontheHLA-GpositiveJEG-3cellswhileasimilaramountoftotalHLA-Gwasobserved.Possiblemechanismsforthedifferencewereanalyzedinthestudysuchascellcold-treatment,peptideloadingandantigenprocessingmachinerycomponents(APM)aswellasβ2microglobulin(β2-m)expression.DatarevealedthattheAPMcomponentcalreticulinmightbeinvolvedinthelowerHLA-GsurfaceexpressiononOCM-1Acells.Takentogether,ourresultsindicatedthatDNAmethylationisanimportantepigeneticmechanismbywhichHLA-Gantigenexpressionismodulatedinmelanomacellsinvitro.Furthermore,tothefirsttime,wehypothesizedthatthedeficiencyofcalreticulinmightbeinvolvedinthelowHLA-Gsurfaceexpressiononthe5-ACtreatedOCM-lAcells.