Partial Correction of the CNS Lysosomal Storage Defect in a Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis by Neonatal CNS Administration of an Adeno-Associated Virus Serotype rh.10 Vector Expressing the Human CLN3 Gene

Abstract

Juvenile neuronal ceroid lipofuscinosis ( JNCL or CLN3 disease) is an autosomal recessive lysosomal storage disease resulting from mutations in the CLN3 gene that encodes a lysosomal membrane protein. The disease primarily affects the brain with widespread intralysosomal accumulation of autofluorescent material and fibrillary gliosis, as well as the loss of specific neuronal populations. As an experimental treatment for the CNS manifestations of JNCL, we have developed a serotype rh.10 adeno-associated virus vector expressing the human CLN3 cDNA (AAVrh.10hCLN3). We hypothesized that administration of AAVrh.10hCLN3 to the Cln3 Dex7/8 knock-in mouse model of JNCL would reverse the lysosomal storage defect, as well as have a therapeutic effect on gliosis and neuron loss. Newborn Cln3Dex7/8 mice were administered 3 · 10 10 genome copies of AAVrh.10hCLN3 to the brain, with control groups including untreated Cln3Dex7/8 mice and wild-type littermate mice. After 18 months, CLN3 transgene expression was detected in various locations throughout the brain, particularly in the hippocampus and deep anterior cortical regions. Changes in the CNS neuronal lysosomal accumulation of storage material were assessed by immunodetection of subunit C of ATP synthase, luxol fast blue staining, and periodic acid-Schiff staining. For all parameters, Cln3Dex7/8 mice exhibited abnormal lysosomal accumulation, but AAVrh.10hCLN3 administration resulted in significant reductions in storage material burden. There was also a significant decrease in gliosis in AAVrh.10hCLN3-treated Cln3 Dex7/8 mice, and a trend toward improved neuron counts, compared with their untreated counterparts. These data demonstrate that AAVrh.10 delivery of a wild-type cDNA to the CNS is not harmful and instead provides a partial correction of the neurological lysosomal storage defect of a disease caused by a lysosomal membrane protein, indicating that this may be an effective therapeutic strategy for JNCL and other diseases in this category.

A novel adeno-associated virus capsid with enhanced neurotropism corrects a lysosomal transmembrane enzyme deficiency

“…In a disease with global pathology such as MPSIIIC where the enzyme is not secreted and thus cannot cross-correct other cells, maximum cell transduction is required. A similar AAV-based approach has been developed in the non-cross correctable neurological disease CLN3, resulting in some disease correction, although neonatal delivery of AAV is often much more effective than delivery to adult mice ( Sondhi et al , 2014 ). Notably an intravenous AAV9 approach in CLN3 was only partly effective, underlining the difficulty of treating non-cross correctable neurological diseases ( Bosch et al , 2016 ).…”

Longitudinal In Vivo Monitoring of the CNS Demonstrates the Efficacy of Gene Therapy in a Sheep Model of CLN5 Batten Disease

“…[2][3][4][5][6] Disease-relevant animal models are invaluable for the development and validation of therapies. However, encouraging preliminary data from gene therapy studies in murine forms 2,3,7,8 need careful consideration before proceeding to translation in human medicine because there are serious caveats with studies in mice. The lissencephalic mouse brain lacks major neuroanatomical structures prominent in the human brain and is very much smaller, 0.4 g versus 1.4 kg, and the neuropathology in many NCL mouse models varies from that seen in the analogous human diseases.…”

Neonatal brain-directed gene therapy rescues a mouse model of neurodegenerative CLN6 Batten disease

“…In the past, AAV-mediated gene therapies have been reported to partially correct features of the disease phenotype in a model of CLN3 disease, which similar to CLN6 disease is caused by a defective transmembrane protein. Sondhi and colleagues showed a partial restoration of the neuropathological phenotype following multiple intracranial injections of AAVrh.10.CAG.hCLN3 in neonatal Cln3 ex7-8 mice (26). Bosch et al demonstrated that in young adult Cln3 ex7-8 mice intravenous administration of scAAV9 carrying CLN3 under the control of a weak neuronal promoter corrected the neuropathology up to 5 months post vector administration (27).…”