Adeno-Associated Viral Vectors Serotype 8 for Cell-Specific Delivery of Therapeutic Genes in the Central Nervous System

Abstract

Adeno-associated viruses (AAVs) have become highly promising tools for research and clinical applications in the central nervous system (CNS). However, specific delivery of genes to the cell type of interest is essential for the success of gene therapy and therefore a correct selection of the promoter plays a very important role. Here, AAV8 vectors carrying enhanced green fluorescent protein (eGFP) as reporter gene under the transcriptional control of different CNS-specific promoters were used and compared with a strong ubiquitous promoter. Since one of the main limitations of AAV-mediated gene delivery lies in its restricted cloning capacity, we focused our work on small-sized promoters. We tested the transduction efficacy and specificity of each vector after stereotactic injection into the mouse striatum. Three glia-specific AAV vectors were generated using two truncated forms of the human promoter for glial fibrillar acidic protein (GFAP) as well as a truncated form of the murine GFAP promoter. All three vectors resulted in predominantly glial expression; however we also observed eGFP expression in other cell-types such as oligodendrocytes, but never in neurons. In addition, robust and neuron-specific eGFP expression was observed using the minimal promoters for the neural protein BM88 and the neuronal nicotinic receptor β2 (CHRNB2). In summary, we developed a set of AAV vectors designed for specific expression in cells of the CNS using minimal promoters to drive gene expression when the size of the therapeutic gene matters.

Argininosuccinic aciduria fosters neuronal nitrosative stress reversed by Asl gene transfer

“…In murine models, AAV8 is known for its ability to widely transduce the brain after intracranial administration 32 , 33 . After systemic injection, most of the organs and especially the liver are successfully targeted 35 but the neurotropism is influenced by the age of infusion and the dose of vector administered.…”

Argininosuccinic aciduria fosters neuronal nitrosative stress reversed byAslgene transfer

“…In murine animal models, AAV8 is known for its ability to widely transduce the brain after intracranial administration 36,37 . After systemic injection, most of the organs and especially the liver are successfully targeted 38 but the neurotropism is influenced by the age of infusion and the dose of vector administered.…”

“…neuronopathic Gaucher disease, mucopolysaccharidosis type I and II). Depending on the pathophysiology of the disease, specific brain cell-types can be selectively targeted in modifying either promoter and/or age at injection 36,37 . The animal was placed in the centre of a plastic box (40 x 40 cm floor) and video-recorded for 5 minutes.…”

AAV-Mediated Astrocyte-Specific Gene Expression under Human ALDH1L1 Promoter in Mouse Thalamus

“…One possible reason is that serotype of AAV virus could affect cell-type specificity of virus infection, as many studies previously reported [ 22 23 24 ]. Natural AAV viruses have a specific pattern of infection that reflects the interaction and recognition between the viral capsid, envelope and receptors expressed in susceptible cells.…”