醫(yī)學(xué)微生物學(xué)教學(xué)課件：血免HIV

Desireforlife

SufferingInnocenceface"evil"InnocentvictimsRetroviridaeRetroviruses(familyRetroviridae)areenveloped,doublesinglestranded(+)RNAvirusesthatreplicatethroughaDNAintermediateusingreversetranscriptase.Thislargeanddiversefamilyincludesmembersthatareoncogenic,areassociatedwithavarietyofimmunesystemdisorders,andcausedegenerativeandneurologicalsyndromes.

Family:RetroviridaeGenusFeaturesExamples1.AlpharetrovirusSimple,OncoAvianleucosisvirus,RSV2.BetaretrovirusSimple,OncoMouseMammaryTumorVirus3.GammaretrovirusSimple,OncoMurineleukemiavirus(Moloney,Harvey)4.DeltaretrovirusComplex,OncoBovineLeukemia,HumanTCellLeukemia(HTLV)5.EpsilonretrovirusComplex,OncoWalleyeDermalSarcoma6.LentivirusComplexHIV,Visna,EIAV7.SpumavirusComplexSimianFoamyVirusHIVandAIDSRetroviridae,lentivirusgenus教學(xué)大綱掌握內(nèi)容HIV形態(tài)結(jié)構(gòu)、復(fù)制及培養(yǎng)特性、傳播途徑、致病機(jī)制及引起疾病、微生物學(xué)檢查法。熟悉內(nèi)容HIV基因組結(jié)構(gòu)與功能了解內(nèi)容HIV疫苗及抗病毒治療的研究進(jìn)展1981年6月美國CDC首次報道1983年和1984年從AIDS患者分離到病毒1986年正式稱為人類免疫缺陷病毒HIV發(fā)現(xiàn)歷史EpidemiologyOver6800newHIVinfectionsadayin2007Morethan96%areinlowandmiddleincomecountries

About5800areinadultsaged15yearsandolderofwhom:almost50%areamongwomenabout40%areamongyoungpeople(15-24)AglobalviewofHIVinfectionin200733millionpeople[range:30-36million]livingwithHIVHIV

infection1-5051-100101-500501-10001001-50005000-10000>10000HIVPropertiesRetroviridae,lentivirusgenus形態(tài)學(xué)結(jié)構(gòu)：中等大小球形顆?；蚪Y(jié)構(gòu)兩條單股RNA，長約9.2KB結(jié)構(gòu)基因：env、pol、gag調(diào)節(jié)基因：tat、rev、nef、vif、vpu、vpr逆轉(zhuǎn)錄酶有包膜gp120糖蛋白、gp41糖蛋白HIVPropertiesHIVProperties刺突gp120（與CD4分子結(jié)合）跨膜蛋白gp41（介導(dǎo)膜融合作用）內(nèi)膜蛋白（基質(zhì)蛋白）：P17衣殼蛋白（P24）核衣殼蛋白（P7）反轉(zhuǎn)錄酶、整合酶、蛋白酶（+）ssRNA×2核衣殼及核心包膜env基因編碼gag基因編碼pol基因編碼HIVReplicationHIVReceptorsReceptor:CD4moleculesCoreceptors:ChemokinereceptorsMainly:CXCR4andCCR5

OtherchemokinereceptorsEntryintothecellT4(CD4+)cellsaremajortargetReceptor1HumanHeLaCellHumanHeLaCelltransfectedwithCD4antigenNOTINFECTEDINFECTEDHIVReceptorsHIVReceptorsCD4CD4CD4HIVCCR5(CXCR4)CCR5(CXCR4)chemokineMutantCCR5Macrophage(Tcell)CCR5isachemokinereceptor?SomeinfectedpeopledonotgetAIDSCellswithmutantCCR5moleculesarenotinfectedbyHIVPersonswithheterozygousmutantCCR5moleculesprogresstoAIDSmoreslowly,25%oflongtermsurvivorsareCCR5orCCR2mutants(deletions)將HIV分兩型HIV-1：流行于世界各地HIV-2：只流行于非洲一般說HIV指的是HIV-1

ClassificationandVariationTheHIVthatinfectsapatientisverydifferentfromthatseenbythetimeAIDSappearsHeterogeneouspopulationsofviralgenomesarefoundinaninfectedindividual.Theregionsofgreatestdivergenceamongdifferentisolatesarelocalizedtotheenvgene,gp120VaccineproblemClassificationandVariationHIVCulture

OnlyCD4+cellAnimalmodel

HIViscompletelyinactivatedbytreatmentfor10minutesatroomtemperaturewith10%householdbleach50%ethanolor35%isopropanol0.5%Lysol0.5%paraformaldehyde0.3%hydrogenperoxide.Disinfection&InactivationDisinfection&InactivationExposuretoundilutedbleachforatleast30secondsisnecessaryforinactivationwhenHIVispresentinclottedorunclottedbloodinaneedleorsyringe.HIVisreadilyinactivatedinliquidsor10%serumbyheatingat56oCfor10minutesHIVInfectioninHumansHIVTransmission

Sexually------

STDSafersex:condomBloodborneDonotbeanIDU(injectiondrugusers),donotsharetheneedlesClearblood/bloodproductionMother-infantNotthroughkissing,mosquitobite,handshaking,holdingTypicalcourseofHIVinfectionPrimaryInfection(Acuteinfection)ClinicalLatencyAIDS-relatedcomplex(ARC)

AIDSPrimaryInfection(Acuteinfection)Fever,pharyngitis,lymphadenectasis,skinmaculopapulareruption，andmucosalulcerabout1～2weeksClinicalLatencyHIVcannotbedetectedintheperipheralbloodAbsenceofclinicalsymptoms5～15years

AIDS-relatedcomplex(ARC)

FeverNightsweatLassitudealloverthebodyChronicbacillarydiarrheaContinuouslymphadenectasisAIDSPlasmaviralloadOpportunisticInfections(OI)CancersNeurologicdisease:AIDSchronicbrainsyndromeAIDSOpportunisticInfections(OI)Protozoa:CryptosporidiuminfectionFungi:Blastomycesalbicans,PneumocystiscariniiBacteria:MycobacteriaViruses:HerpesvirusesCancersKapositumor

Hokdkin’sdiseaseCancerofanusCancerofthecervixAIDSNeurologicdisease:AIDSchronicbrainsyndromeAIDSdementiacomplex:mostcommonneurologicsyndrome,in25–65%ofAIDSpatientsSubacuteencephalitisVacuolarmyelopathyAsepticmeningitisPeripheralneuropathy卡氏肺囊蟲感染OpportunisticInfections(OI)CancersTypicalcourseofuntreatedHIVinfection.引起機(jī)體免疫系統(tǒng)損傷，造成免疫功能障礙HIV對CD4+T細(xì)胞的損害對其他免疫細(xì)胞的損害：B細(xì)胞、單核細(xì)胞等對神經(jīng)細(xì)胞的損害---AIDS癡呆綜合征HIV靶細(xì)胞：CD4+T細(xì)胞HIV受體：CD4分子輔助受體：CCR5、CXCR4、CCR2、CCR3※TheMechanismofHIVPathogenesisHIV對CD4+細(xì)胞的破壞細(xì)胞融合通透性增加細(xì)胞凋亡CTL、ADCC自身免疫神經(jīng)細(xì)胞的損害※直接殺傷免疫病理TheMechanismofHIVPathogenesis神經(jīng)細(xì)胞的損害約有40%-90%的AIDS患者有不同程度神經(jīng)癥狀病毒免疫逃逸的機(jī)理CD4+T細(xì)胞大量減少，使整個免疫系統(tǒng)失效病毒基因整合位于染色體，使宿主細(xì)胞長期呈“無抗原”狀態(tài)病毒包膜蛋白高度變異性，逃逸免疫系統(tǒng)的識別LaboratoryDiagnosisSerologydetermination2.Measureofviralnucleicacidorantigens3.VirusisolationSerologydeterminationScreeningassaysELISA，RIA,ConfirmatoryassaysWesternblotP24,gp41,gp120,gp160MeasureofviralnucleicacidorantigensDetectingnucleicacidNucleicacidhybridizationandPCR,detectingprovirusDNAinthecellRT-PCR:detectingRNAofvirusinthebloodplasmaViralloadpredictssurvivaltimeMeasureofviralnucleicacidorantigensDetectionofantigensELISA:detectingcapsidprotein(p24)ofHIVinthecellLowlevelsofcirculatingp24antigencanbedetectedintheplasmabyELISAsoonafterinfectionVirusisolation

Co-culturetheperipheralbloodmononuclearcell（PBMCorT-cell)oftheinfectiouswiththehealthadults’

PBMC，about4～6weeksWindowPeriodThisistheperiodoftimeafterbecominginfectedwhenanHIVtestisnegative90percentofcasestestpositivewithinthreemonthsofexposure10percentofcasestestpositivewithinthreetosixmonthsofexposureWindowPeriod5101520253035ELISAp24DNAPCRRNADayspostinfectionDiagnosisavailableWindowperiod(infectedwithnovirusfinding)WindowPeriodHIVTestingThoserecentlyexposedshouldberetestedatleastsixmonthsaftertheirlastexposureScreeningtest(EIA/ELISA)vs.confirmatorytest(IFA)

EIA/ELISA(Reactive)

RepeatEIA/ELISA(Reactive) IFA(Reactive)

PositiveforHIVPrevention,treatment&controlAntiviraldrugsVaccinesagainstHIVControlmeasuresHealtheducation

Antiviraldrugs

Threetypesofdrugsarecurrentlyused:nucleosideandnucleotidereversetranscriptase(RT)inhibitorsnon-nucleosidereversetranscriptaseinhibitorsproteaseinhibitors(PIs)SomeAlternativeTherapies

Virusadsorptioninhibitors–interferewithvirusbindingtocellsurfacebyshieldingthepositivelychargedsitesonthegp-120glycoproteinPolyanioniccompounds

Viralcoreceptorantagonists–competeforbindingattheCXCR4(X4)andCCR5(R5)coreceptorsBicyclamsandligandsCombinationTherapyCombinationtherapyoftencalledHAARTisstandardcareforpeoplewithHIV.Monotherapycreatedvirusresistancetotheindividualdrug.Somecombinationtherapiesincreasethetimeittakesforthevirustobecomeresistant.CombinationsofaPIorNNRTIwithoneortwoNRTI’sisoftenrecommended.Combinationtherapymayreduceindividualdrugtoxicitybyloweringthedosageofeachdrug聯(lián)合交替使用2種HIV逆轉(zhuǎn)酶抑制劑和一種蛋白抑制劑無法清除整合的病毒，不能徹底清除病毒藥物有副作用在中國年均費(fèi)用8萬RMB

雞尾酒療法（HAART）

DavidHoProf.ofRockefellerUniversityChiefScientistofAaronDiamondInstitute2001:PresidentialMedal.治療的目的抑制病毒復(fù)制至血漿可檢測水平之下降低淋巴組織病毒載量使對機(jī)會致病病原體的免疫反應(yīng)得以恢復(fù)延長病人生存期CD4counts：Flowcytometry

HIVviralload：RT-PCRProgress/Prognostic/therapyeffectVaccinesagainstHIVVaccinedevelopmentisdifficultHIVmutationisrapidSafetyconcernsLackofanimalmodelHealtheducation&Controlmeasures

OnceapersonisinfectedtheyarealwaysinfectedMedicationsareavailabletoprolonglifebuttheydonotcurethediseaseThosewhoareinfectedarecapableofinfectingotherswithouthavingsymptomsorknowingoftheinfectionHIVAIDS

HIVRiskReductionAvoidunprotectedsexualcontact

UsebarrierssuchascondomsLimitmultiplepartnersbymaintainingalong-termrelationshipwithonepersonTalktoyourpartneraboutbeingtestedbeforeyoubeginasexualrelationshipCondoms

Usingcondomsisnot100percenteffectiveinpreventingtransmissionofsexuallytransmittedinfectionsincludingHIVCondoms=SafersexCondoms≠SafesexHIVPostExposureProphylaxis

HIVOccupationalExposureReviewfacilitypolicyandreporttheincidentMedicalfollow-upisnecessarytodeterminetheexposureriskandcourseoftreatmentBaselineandfollow-upHIVtestingFourweekcourseofmedicationinitiatedonetotwohoursafterexposure