New Treatment of the Brain in Niemann Pick C

Abstract SignificanceNiemann Pick Type CdiseaseNPCis a devastating inherited neurodegenerative lysosomal storage disease caused by mutations in the NPCgenewhich encodes for an intracellular membrane cholesterol transporterCurrentlythere are few treatment options for NPCProtein replacement therapy is not possiblebecause the NPCprotein is an insoluble membrane transporterGene therapy of either human NPCor a long standing mouse model of NPChas not been attemptedowing to the large size of the NPCmRNAwhich exceeds the capacity of common gene therapy viral vectorsIn contrastlarge size genes can be encapsulated in nonviral delivery systems such as Trojan horse liposomesTHLsTHLs are manufactured with a receptor specific monoclonal antibodyMAbwhich acts as a molecular Trojan horse to ferry the THL from blood into the nuclear compartment of brain cellsIn prior workTHL mediated delivery of plasmid DNA has produced therapeutic effects in mouse models of neural disease includingParkinson s diseasebrain canceror lysosomal storage diseaseHypothesisThe hypothesis tested in the present work is that the NPCgene can be effectively replaced in brainand in peripheral organswith regular intravenousIVadministration of THLs encapsulating plasmid DNA encoding the NPCgeneThis hypothesis is supported by prior work in the NPCmouse model wherein embryos were transfected with the wild type NPCgene and these transgenic mice were cross bred with the NPCmouseReplacement of the NPCgene in brain effectively cured the disease in the NPCmousePreliminary DataPrior work with a lysosomal storage disease mouse model has shown it is possible to achieve replacement of the wild type gene in mouse brain with IV administration of THLs carrying the expression plasmid DNA encoding the lysosomal enzyme geneThe THLs are targeted with a MAb specific for the mouse transferrin receptorTfRPrior work has also shown that repeatchronic IV administration of THLs causes no toxicity or immune reactionsSpecific AimsFirstTHLs will be manufacturedand these THLs are targeted with the MAb specific for the mouse TfRand encapsulate an expression plasmid DNA encoding for the NPCcDNAThe expression plasmid DNA will be engineered with methods used previously for therapeutic plasmid DNASecondthe potency of the THLs will be assessed in cell culture using human NPCfibroblastsThirda colony of NPCmice will be generated for this project producing at leasthomozygote miceThe mice will undergo treatment forweeks with weekly IV administration of THLs carrying the NPCDNAbeginning at the age ofweeksTreatment efficacy will be assessed with survivalbody and organ weightsbrain histologyperipheral organ histologyas well as brain biochemical parameters of NPCgene expressionThis research can be translated to human NPCbecause prior work as shown it is possible to deliver transgenes to virtually all cells in the brain of the adult non human primate with IV administration of THLs