病毒感染与免疫英文Viralinfectionandimmunity

ViralinfectionandimmunityOutlineSectionIViralpathogenesisI.TransmissionroutesII.FormsofviralinfectionsIII.PathogenesisofviralinfectionsSectionIIAntiviralimmunityI.InnateimmunityII.SpecificimmunitySection1ViralpathogenesisI.TransmissionroutesTherouteofviralinfectionA.HorizontaltransmissionB.VerticaltransmissionA.HorizontaltransmissionRespiratorytractAlimentarycanalSkinandmucousmembraneGenitaltractBlood:Injection,transfusion,transplantationArthropod-bornecivetcatB.VerticalTransmissionThroughplacentacongenitalinfections,congenitaldeformityThroughbirthcanalinfectionofnewbornVerticalTransmissionTheviruseswhichcanresultincongenitalinfections：rubellaviruscytomegalovirus(CMV)herpessimplexvirus(HSV)hepatitisBvirus(HBV)humanimmunodeficiencyvirus(HIV)III.VirusSpreadintheHostA.LocalReplicationandLocalSpreadB.DisseminationfromthePortalofEntryMultiplicationinTargetOrgansA.LocalReplication&LocalSpreadB.DisseminationfromthePortalofEntryDisseminationthroughBloodstreamViremiaDisseminationthroughNervesThroughBloodstreame.g.•Poliovirus•Measlesvirus•MumpsvirusThroughNervese.g.•Rabiesvirus•Herpesvirus•PoliovirusII.FormsofviralinfectionsAcuteviralinfectionPersistentviralinfectionTypesofViralInfectionChronicinfectionLatentinfectionSlowinfectionNaturalhistoryofacuteandpersistenthumaninfections.A.ChronicinfectionContinuedpresenceofinfectiousvirusfollowingtheprimaryinfectionandmayincludechronicorrecurrentdisease.Viruscanbecontinuouslydetected.HBV,ect.B.Latentinfectionvirusisusuallynotdetectablebutpatientmayhaveperiodicout-breaksofdisease.characterizedbythelackofdemonstrableinfectiousvirusbetweenepisodesofrecurrentdiseaseHSV-1intrigeminalganglionHSV-2inlumbarandsacralgangliaLatencyandrecurrenceinherpessimplexvirusinfectionsColdsorescausedbyherpesvirustype1RecurrenceofLatentvirusinfectionsShinglescausedbyvaricella-zostervirusRecurrenceofLatentvirusinfectionsC.Slowvirusinfectioncharacterizedbyalongpreclinicalperiodextendingformonthsoryearsfromthetimeofexposuresubacuteprogressivecausedby：Lentivirus(HIV)unconventionalvirus(prion).III.PathogenesisofviralinfectionsPathogenesisofviralinfectionsA.DirectdamagetoinfectedhostcellsB.ImmunopathologicalinjuryA.Directdamagetoinfectedhostcells1.Cytocidalinfection2.Steadystateinfection3.Integrationandtransformation1.CytocidalinfectionMostproductiveinfectionsarecalledcytocidalinfectionbecausetheykillthehostcells.※Cytopathiceffect(CPE):CPEaremorphologicchangesofhostcellswhichinfectedbycytocidalvirus,includingcellswollenandround,celllysis,ornecrosis,andtheformationofinclusionbody,orpolykaryocytesCPECPENormalcellsCytopathiceffect※virusinclusionbodiesInthesomeofvirus-infectedcells,roundorovalpatcheswithdifferentcolorandstructurecanbeobservedatthelightmicroscope.Itis:•Aggregationofvirusparticles•Tracesofthevirusmultiplication•VirusinducedcellreactantsRabiesvirusinclusionbodiesnegribodyPolykaryocytesRSVinfecteccellsMeaselsvirusinfectedcells2.SteadystateinfectionViralnucleicacidremaininspecifichostcellsindefinitely;progenyvirusmayormaynotbeproduced.Features:•Commonlyinducedbyenvelopedvirus•Virusreleasebybuddingchildvirus•Newantigensmaybeproduced----so,theinfectedcellsmaybeattackedbyhostimmunesystem3.IntegrationandtransformationIntegrationAllorpartofvirusnucleicacidbecomesintegratedintothegenomeatspecificoranysiteinhostcells.Outcomes:iscloselyrelatedtotumorformation.SectionIIAntiviralimmunityAntiviralimmunityInnateDefensesIFNNeutralizingantibodyI.InnateimmunityInnateimmunefactorsagainstviralinfectionSkin-mucousmembraneInterferonsNaturalkillercellmacrophagesaheterogeneousgroupofglycoproteinsproducedbyhumanandotheranimalcellsafterviralinfection(orafterexposuretootherinducers.)FunctionsofIFNs:anti-virus,anti-tumor,immunomodulationInterferon(IFN)InnateDefensesprincipalsourceinducerIFN-αleukocytevirus/dsRNAIFN-βfibroblastvirus/dsRNAIFN-γlymphocyteantigen/mitogenInterferonsInnateDefensesIFNgenesnormallyarenotexpressedThestronginducers:Virusesanddouble-strandedRNAsInductionisnotspecificforaparticularvirusInductionIFN-α/IFN-βNonspecificDefensesActionofIFN-α/IFN-βactbyinducethesynthesisofthreecell-encodedproteins2,5-oligoadenylatesynthetaseRibonucleaseProteinkinaseRInterferonsNKcellDirectlylysedvirusinfectedcellsno“lagphase”EffectiveEarlyNoantigen-specificNKcellII.AdaptiveimmunityHumoralimmunityNeutralizingantibodyAntibodieswhichbindtothevirus,usuallytothepeplomerandcapsomer,andblockthevirusfrombindingandenteringintohostcellIgG,IgM,IgAcan“neutralize”extracellularvirusesNeutralizingAntibodyIgAconfersprotectionagainstvirusesthatenterthroughtherespiratoryandgastrointestinalmucosaIgM,IgGprotectagainstvirusenterorarespreadthroughthebloodVirusinfectionwithoutneutralizingAbVirusinfectionwithneutralizingAbCellularImmunityCellularImmunityCytotoxicTlymphocytes(CTL)Features:MHC-ⅠrestrictionViralspecificityHighlyeffectiveLatephaseMostlyimportantfactorinrecoveryfromtheviralinfectionLysisofvirus-infectedcellsbycytotoxiceffectorcells.Questions1.Typesofvirusinfection2.WhatisIFN?Feature