Maximizing lentiviral vector gene transfer in the CNS

Abstract

Gene transfer is a widely developed technique for studying and treating genetic diseases. However, the development of therapeutic strategies is challenging, due to the cellular and functional complexity of the central nervous system (CNS), its large size and restricted access. We explored two parameters for improving gene transfer efficacy and capacity for the selective targeting of subpopulations of cells with lentiviral vectors (LVs). We first developed a second-generation LV specifically targeting astrocytes for the efficient expression or silencing of genes of interest, and to better study the importance of cell subpopulations in neurological disorders. We then made use of the retrograde transport properties of a chimeric envelope to target brain circuits affected in CNS diseases and achieve a broad distribution. The combination of retrograde transport and specific tropism displayed by this LV provides opportunities for delivering therapeutic genes to specific cell populations and ensuring high levels of transduction in interconnected brain areas following local administration. This new LV and delivery strategy should be of greater therapeutic benefit and opens up new possibilities for the preclinical development of gene therapy for neurodegenerative diseases.

Revisiting gene delivery to the brain: silencing and editing

“…79 These viral envelopes do not necessarily warrant specific cell-type tropism, and in most cases they are combined with cell-type-specific promoters to instigate transgene expression in the desired cell type. [81][82][83] Lentiviral vectors can deliver 8 kb of sequence, and that means they can accommodate larger transgenes than AAV vectors. 26 Lentiviral vectors have the advantages of highefficiency infection of dividing and non-dividing cells, longterm stable expression of a transgene, and low immunogenicity.…”

Mitochondrial biogenesis in developing astrocytes regulates astrocyte maturation and synapse formation

“…The prominent role of astrocytic PGC-1a in regulating postnatal astrocyte development and synapse formation was confirmed in vivo by re-expressing PGC-1a in developing astrocytes on P5. The amGluR5cKO and control tdTomato mice were injected with an astrocyte-specific Lentivirus expressing PGC-1a or GFP or DsRed (Figures S7A and S7B; Petrelli et al, 2020;Humbel et al, 2021). RT-PCR analysis showed that the injection of Lenti:PGC-1a into the PFC of am-GluR5cKO-tdTomato mice significantly increased PGC1a mRNA levels (Figure S7C).…”

Challenges and Opportunities of Targeting Astrocytes to Halt Neurodegenerative Disorders

“…Notably, lentiviruses pseudotyped with glycoproteins from the lymphocytic choriomeningitis virus, the Moloney murine leukemia virus [229], the Mokola virus [230,231], or the chikungunya virus [232] were reported to acquire tropism towards astrocytes. As discussed in the context of AAV development, the use of an astrocyte-specific promoter is also valuable to achieve cell-specific gene transfer, mainly with the addition of a miRNA de-targeting strategy to abolish residual transgene expression in neuronal cells [230,233,234].…”