Gene therapy for Alzheimer's disease: Characterising lentivirus and adeno-associated virus spread from the adult mouse hippocampus
Alzheimer’s Disease is a neurodegenerative condition with progressively worsening memory and cognitive function, which ultimately results in death. The two major neuropathological hallmarks of AD are extracellular amyloid-beta (Aβ) plaques and intracellular neurofibrillary tau tangles (NFTs). Other pathways and neuronal mechanisms are also likely to be affected as AD is a complex disease resulting from anomalies in components of different pathways. Currently, apart from a few FDA approved drugs which serve to delay symptom progression through slowing neurotransmitter breakdown (Cholinesterase inhibitors) and cell damage (NMDA-receptor antagonist), no effective treatment of the underlying causes of AD is available. One of the hypothesised underlying cause of AD is the formation of extracellular Aβ plaques. Current work in the Neural Development and Disease (NDD) lab have researched viral-mediated gene therapy as a means to introduce a neuroprotective secreted amyloid precursor protein α (sAPPα) gene intracranially. This project’s primary aim was optimising and comparing the spread between lentiviral (LV) and adeno-associated viral (AAV) vectors; along with the effects of systemically delivering an osmotic agent, mannitol. Viral spread would be determined by the use of a GFP reporter gene, where expression indicated transduction and extent of viral spread. This project has showed a significant improvement in transduction efficiency when using an AAV vector to deliver a reporter gene. It efficiently achieved widespread transduction of the CNS from a unilateral injection at the hippocampus. However, while LV had a limited spread in comparison to AAV9, it would be useful for targeted delivery of treatment. Mannitol did not produce any significant effect on vector spread. The secondary aim was to create a plasmid to visualise secretion of sAPPα from virally transduced cells. Once packaged into a lentiviral vector, the plasmid was shown to successfully transduce primary neurons in vitro, but expression of reporter genes were not observed in vivo.
Advisor: Hughes, Stephanie
Degree Name: Master of Science
Degree Discipline: Biochemistry
Publisher: University of Otago
Keywords: Alzheimer's Disease; Gene therapy; Viral vector; lentivirus; adeno-associated virus; sAPPα; mannitol
Research Type: Thesis