Transgenic Expression of Human Glial Cell Line-Derived Neurotrophic Factor from Integration-Deficient Lentiviral Vectors is Neuroprotective in a Rodent Model of Parkinson's Disease

Abstract

Standard integration-proficient lentiviral vectors (IPLVs) are effective at much lower doses than other vector systems and have shown promise for gene therapy of Parkinson's disease (PD). Their main drawback is the risk of insertional mutagenesis. The novel biosafety-enhanced integration-deficient lentiviral vectors (IDLVs) may offer a significant enhancement in biosafety, but have not been previously tested in a model of a major disease. We have assessed biosafety and transduction efficiency of IDLVs in a rat model of PD, using IPLVs as a reference. Genomic insertion of lentivectors injected into the lesioned striatum was studied by linear amplification-mediated polymerase chain reaction (PCR), followed by deep sequencing and insertion site analysis, demonstrating lack of significant IDLV integration. Reporter gene expression studies showed efficient, long-lived, and transcriptionally targeted expression from IDLVs injected ahead of lesioning in the rat striatum, although at somewhat lower expression levels than from IPLVs. Transgenic human glial cell line-derived neurotrophic factor (hGDNF) expression from IDLVs was used for a long-term investigation of lentivectormediated, transcriptionally targeted neuroprotection in this PD rat model. Vectors were injected before striatal lesioning, and the results showed improvements in nigral dopaminergic neuron survival and behavioral tests regardless of lentiviral integration proficiency, although they confirmed lower expression levels of hGDNF from IDLVs. These data demonstrate the effectiveness of IDLVs in a model of a major disease and indicate that these vectors could provide long-term PD treatment at low dose, combining efficacy and biosafety for targeted central nervous system applications.

Intrastriatal Delivery of Integration-Deficient Lentiviral Vectors in a Rat Model of Parkinson’s Disease

“…Examination of reporter gene (enhanced green fl uorescent protein, eGFP ) and therapeutic transgene (glial cellderived neurotrophic factor, GDNF ) expression has shown efficient, long-lived, and transcriptionally targeted expression from IDLVs in the striatum of injected rats. We have confi rmed the lack of signifi cant integration of IDLVs in injected rat brains by linear amplifi cation-mediated PCR analysis followed by deep sequencing and insertion site analysis [ 17 ].…”

“…Very recently, we have assessed biosafety and transduction efficiency of IDLVs in an animal model of Parkinson's disease, the 6-hydroxydopamine (6-OHDA)-lesioned rat , with IPLVs used as a reference [ 17 ]. Examination of reporter gene (enhanced green fl uorescent protein, eGFP ) and therapeutic transgene (glial cellderived neurotrophic factor, GDNF ) expression has shown efficient, long-lived, and transcriptionally targeted expression from IDLVs in the striatum of injected rats.…”

FSD-C10, a Fasudil derivative, promotes neuroregeneration through indirect and direct mechanisms

“…Local release of NT-3 also reduces astrogliosis, a main cause of MS plaque formation4041. GDNF, a member of the TGF-β superfamily42, promotes survival and differentiation of dopaminergic and motor neurons4344, selectively enhances regrowth of damaged axons45, and induces myelin formation1846. BDNF is well-known to promote neuronal survival and axonal growth4748.…”

Destination Brain: the Past, Present, and Future of Therapeutic Gene Delivery

“…Research later reported that prior peripheral LV immunization elicited an immune response to a subsequent CNS-injected LV only when both LVs encoded the same transgene (Abordo-Adesida et al, 2005). Since LVs are integration proficient, there’s a risk of insertional mutagenesis, and therefore integration-deficient vectors have been used as well (Lu-Nguyen et al, 2014). Recently, a first-ever LV-based Phase I PD clinical trial was completed (Table 5).…”