Distinct Overexpression of Fas Ligand on T Lymphocytes in Aplastic Anemia

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摘要 IncreasedexpressionofFasbyhematopoieticprogenitorsinaplasticanemia(AA)suggeststhatFas/Fasligand(FasL)systemplaysakeyroleintheformationofseverepancytopenia.Tofurtherconfirmtheabovehypothesis,Tcellsfrom8patientswithAAweresystematicallystudiedfortheirFasL'sdistributionpattern,releasingmannerandproapoptoticactivity,comparedwithnormalrestingTcellsandartificiallyactivatedTcellblasts.TheresultsdemonstratedthatAATcellsabnormallyexpressedlowlevelsofmembrane-boundFasLandcontainedhighlevelsofintracellularFasLwhichcouldbetriggeredtoreleasebyhigh-dosephytohemagglutinin(PHA)pulse-stimulation.ThesupernatantsfromthePHA-stimulatedAATcellshadapparentcytotoxicityagainstFasL-sensitiveJurkatcells,whichcouldbesignificantlyinhibitedbymonoclonalantibodyagainstFasLinadose-dependentmanner,ornearlycompletelyabrogatedbyultracentrifugation.TheabovephenomenaalsoappearedonartificiallyactivatedTcellblasts,butthiswasnotthecaseonnormalrestingTcells.TheseresultsindicatethatAATcellisatypeof'preactivated'Tlymphocyte,characterizedbyoverexpressionofFasL,especiallyintracellularFasLwhichcanbestimulatedtoreleaseinbioavtiveexosomesboundform.Takentogether,ourdataprovidefurtheranddirectevidenceforthehypothesisthatTcellsmightmediatethedestructionofhematopieticprogenitorinAAthroughFas/FasLsystem.
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出版日期 2004年02月12日(中国期刊网平台首次上网日期,不代表论文的发表时间)
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