CD3-specificmonoclonalantibodywasthefirstoneusedforclinicalpracticeinfieldoftransplantation.Recently,renewedinterestshaveelicitedinitscapacitytopreventautoimmunediabetesbyinducingimmunetolerance.Inthisstudy,wetestedwhetherthisantibodycanalsobeusedtotreatanotherkindofautoimmunediseasemyastheniagravis(MG)andexploredthepossiblemechanisms.MGiscausedbyanautoimmunedamagemediatedbyantibody-andcomplement-mediateddestructionofAChRattheneuromuscularjunction.WefoundthatadministrationofCD3-specificantibody(Fab)2toananimalmodelwithexperimentalautoimmunemyastheniagravis(EAMG)(B6micereceived3timesofAChR/CFAimmunization)couldnotsignificantlyimprovetheclinicalsignsandclinicalscore.Whenthepossiblemechanismsweretested,wefoundthatCD3antibodytreatmentslightlydown-regulatedtheT-cellresponsetoAChR,modestlyup-regulationthemusclestrength.AndnosignificantdifferenceinthetitersofIgG2bwasfoundbetweenCD3antibodytreatedandcontrolgroups.ThesedataindicatedthatCD3-specificantibodywasnotsuitablefortreatingMG,anantibody-andcomplementmediatedautoimmunedisease,afterthisdiseasehasbeenestablished.TheroleofCD3-specificantibodyintreatingthiskindofdiseaseremainstobedetermined.
