Triptolideisanatural,biologicallyactivecomponentderivedfromChineseherbTripterygiumWilfordiiHookF.(TWHF)whichiseffectiveintheclinicaltreatmentofautoimmunediseases,however,themechanismsbywhichtriptolideexertsimmunosuppressionremainfullyunderstood.Theprimaryofthisstudyistodemonstratewhethertriptolidecanaffectphenotype,cytokineproductionandallogeneicTcell-stimulatorycapacityofdendriticcells(DCs)whicharecriticalintheinductionofimmuneresponseortolerance.PhenotypicanalysisshowthattriptolidedoesnotaffecttheexpressionofMHC(Ia^b),CD80,CD86andCD40ofDCstimulatedwithornotLPS,butsignificantlyinhibitsIL12p70productionbyDCinadose-dependentmanner.Triptolide-treatedDCsexhibitareducedcapacitytostimulateproliferationofallogeneicCD4^+Tlymphocytes.Therefore,triptolide-mediatedimmunosuppressionmaydue,inpart,totheinhibitionofIL-12p70productionandimpairmentofallogeneicTcell-stimulatorycapacityofDCs.Ourresultsmayprovideapossiblemechanisticexplanationfortheeffectivenessoftriptolideinthetreatmentofautoimmunediseases.
