简介：Exosomes,secretedbymanylivecells,aresmallnon-cellvesicleswithnanoparticle-gradesize.Inadditiontotheoriginalfunctionofdiscardingtheuselessfulmembranemolecules,exosomesareinvolvedinarangeofimmunoregulatoryfunctions.Dendriticcell-derivedexosomesandtumor-derivedexosomesarethebestcharacterizedvesicleswithpotentantitumoreffectbyefficienflyinducingimmuneresponse.Down-regtdationofimmuneresponseorinductionofimmunetoleranceisanotherinterestingfunctionofexosomes，Furtherfunctionalstudiesoftheexosomeswillshedlightontheapplicationofexosomes。

简介：Toinvestigatetheinfluenceofmycophenolatemofetil(MMF)uponthematurationandtheallo-stimulatoryactivityofculturedprogenitorsofdendriticcells(DCp),andtoevaluatetheeffectsofthepre-treateddentriticcellsofrecipientswithMMFonthetoleranceinductionaswellasitspossiblemechanism,GM-CSFandMMFwereaddedtotheinvitroculturedprogenitorcells,andtheimmuno-phenotypicalanalysiswasperformedbymeansofflowcytometry.ThesecretionofIL-12wasdetectedbyELISAandthestimulatoryactivitiesofDCponallogeneicTcellswereobservedbymixedlymphocytereaction.Twenty-fourC57BL/6miceweredividedinto3groups(eachwith8mice),inwhichgroupAofmiceacceptedallograftsofheartfromBALB/cmice,groupBofmicehadreceiveduntreatedDCpfromdonorsofBALB/cmice7daysbeforetransplantation,andC57BL/6miceingroupCweretreatedbyinjectionwithMMF-treatedallograftsofheartfromBALB/cmice7daysbeforetransplantation.Thesurvivaltimesofallograftsandthechangesofthecytokinelevelsinsereoftherecipientmicewereobservedaftertransplantation.TheexperimentalresultsshowedthatMMFcouldsignificantlyinhibittheexpressionsofthecostimulatorymoleculesCD80andCD86onDCsandthesecretionofIL-12andtheallo-stimulatoryactivitiesofDCswerealsomarkedlyinhibited.ThesurvivaltimesofallograftsingroupBofmicewerelongerthanthoseingroupA,whilethegroupCshowedthelongestsurvivaltimesofallografts,withamarkedreductionintheproductionoftheThltypecytokines.ItisevidentthatMMFhasasuppressiveeffectonthematurationandallo-stimulatoryactivitiesofthecultureddendriticcellprogenitors,thusleadingtoadonorspecifictoleranceinheart-transplantedrecipients.