MicroRNA Profile of Marek’s Disease Virus-Transformed T-Cell Line

  • 格式:pdf
  • 大小:404.30 KB
  • 文档页数:9

JOURNALOFVIROLOGY,Apr.2008,p.4007–4015Vol.82,No.8

0022-538X/08/$08.00ϩ0doi:10.1128/JVI.02659-07

Copyright©2008,AmericanSocietyforMicrobiology.AllRightsReserved.

MicroRNAProfileofMarek’sDiseaseVirus-TransformedT-CellLine

MSB-1:PredominanceofVirus-EncodedMicroRNAsᰔ

YongxiuYao,1YuguangZhao,1HongtaoXu,1LorraineP.Smith,1CharlesH.Lawrie,2

MichaelWatson,1andVenugopalNair1*

DivisionofMicrobiology,InstituteforAnimalHealth,Compton,BerkshireRG207NN,UnitedKingdom,1and

LRFMolecularHaematologyUnit,NuffieldDepartmentofClinicalLaboratorySciences,Universityof

Oxford,OxfordOX39DU,UnitedKingdom2

Received14December2007/Accepted25January2008

ResearchoverthelastfewyearshasdemonstratedtheincreasingroleofmicroRNAs(miRNAs)asmajor

regulatorsofgeneexpressionindiversecellularprocessesanddiseases.Severalviruses,particularlyherpes-

viruses,alsousethemiRNApathwayofgeneregulationbyencodingtheirownmiRNAs.Marek’sdisease(MD)

isawidespreadlymphomatousneoplasticdiseaseofpoultrycausedbythehighlycontagiousMarek’sdisease

virustype1(MDV-1).Recentstudiesusingvirus-infectedchickenembryofibroblastshaveidentifiedatleast

eightmiRNAsthatmaptotheRL/RSregionoftheMDVgenome.SinceMDVisalymphotropicvirusthat

inducesT-celllymphomas,analysisofthemiRNAprofileinT-celllymphomawouldbemorerelevantfor

examiningtheirroleinoncogenesis.WedeterminedtheviralandhostmiRNAsexpressedinMSB-1,a

lymphoblastoidcelllineestablishedfromanMDV-inducedlymphomaofthespleen.Inthispaper,wereport

theidentificationof13MDV-1-encodedmiRNAs(12bydirectcloningand1byNorthernblotting)fromMSB-1

cells.ThesemiRNAs,fiveofwhicharenovelMDV-1miRNAs,maptotheMeqandlatency-associated

transcriptregionsoftheMDVgenome.Furthermore,weshowthatmiRNAsencodedbyMDV-1andthe

coinfectedMDV-2accountedfor>60%ofthe5,099sequencesoftheMSB-1“miRNAome.”Severalchicken

miRNAs,someofwhichareknowntobeassociatedwithcancer,werealsoclonedfromMSB-1cells.Highlevels

ofexpressionofMDV-1-encodedmiRNAsandpotentiallyoncogenichostmiRNAssuggestthatmiRNAsmay

havemajorrolesinMDVpathogenesisandneoplastictransformation.

Marek’sdisease(MD)isanaturallyoccurringrapid-onset

aggressiveT-celllymphomaofpoultry.NamedaftertheHun-

garianveterinarianJos´zefMarek,whofirstreportedthedis-

easein1907(41),thediseaseisinducedbyMarek’sdisease

virustype1(MDV-1),ahighlycontagiousalphaherpesvirus

belongingtothegenusMardivirusofthefamilyHerpesviridae

(31).Apartfrombeingamajordiseaseaffectingpoultryhealth

andwelfare,MDisconsideredtobeanexcellentbiomedical

modelforvirus-inducedlymphoma(7,14).Amongthe100-

plusgenespredictedfortheMDVgenome(40,47,48),the

geneforthebasicleucinezipperproteinMeqisconsideredto

bethemajoroncogene(39,44).SomeofthefunctionsofMeq

associatedwithoncogenicproperties,suchasitsinteraction

withCtBP,parallelthoseofotherviraloncogenicsequences,

suchasadenovirusE1AandEpstein-Barrvirus(EBV)nuclear

antigensEBNA3Aand-3C(6),highlightingtheconvergent

evolutionofoncogenicpathwaysintheseviruses.Recentstud-

ieshavealsoidentifiedtheroleofothergenes,suchasthepp38

(23),viralinterleukin-8(vIL-8)(49),ICP4(15,38),R-LORF4

(33),UL36(32),andMDV-encodedtelomeraseRNA(22,63)

genes,inpathogenesis.

Increasingevidencedemonstratesthatinadditiontothe

directroleofprotein-encodinggenes,noncodingRNAshave

profoundeffectsinmediatingneoplastictransformation(13).Amongthese,the22-nucleotidemicroRNAs(miRNAs)have

emergedasamajorregulatorytierofgeneexpression,withthe

potentialoftargetingupto30%ofgenesinhumans(17,27,

37).Giventheirsmallsizewiththecapabilityforregulating

multiplegenes,severalviruseshaveadoptedthemiRNAma-

chinerytomanipulatethecellularandviralpathwaysofgene

regulationbyencodingtheirownmiRNAs(19,24,26,42).

Amongthedifferentfamiliesofviruses,herpesviruseshave

exploitedthemiRNA-mediatedgeneregulationpathwaymost

successfully,since124ofthe127virus-encodedmiRNAsin

miRBaserelease10.1(http://microrna.sanger.ac.uk)areen-

codedbyherpesviruses.Ithasbeensuggestedthatthe

miRNA-mediatedregulatorymechanismsareverysuitedfor

theherpesviruslifecycle,whichischaracterizedbynuclear

replicationandlatentperiodswithminimalantigenexpression

(19).

SpecificmiRNAsignaturesindifferenttypesoftumorshave

beenidentifiedusinghigh-throughputmicroarrayanalysisof

miRNAexpression(60,64,67).Consideringtheaggressive

natureandrapidonsetoftumorsinducedbyMDV-1,analysis

ofthemiRNAprofileofMDV-transformedtumorcellscould

providefurtherinsightsintoMDoncogenesis.Previousstudies

usingsmallRNAsfromMDV-infectedchickenembryofibro-

blasts(CEF)haveidentifiedseveralmiRNAs,includingeight

MDV-encodedmiRNAsthatmappedtotheMeqandthe

latency-associatedtranscript(LAT)regionofthegenome(8,

9).AlthoughidentificationofMDVandhostmiRNAsinlyti-

callyinfectedCEFisvaluable,understandingtheexpression

profilesofmiRNAsinthelymphocytetargetcellsofMD

lymphomaswouldbecrucialtodelineatetheirrolein