Systemic AAVrh10 provides higher transgene expression than AAV9 in the brain and the spinal cord of neonatal mice.

Yannick Tanguy,Aurore Besse,Stephanie Astord,Mathilde Cohen-Tannoudji,Maria G Biferi,Martine Barkats,Thibaut Marais

doi:10.3389/fnmol.2015.00036

Abstract

Systemic delivery of self-complementary (sc) adeno-associated-virus vector of serotype 9 (AAV9) was recently shown to provide robust and widespread gene transfer to the central nervous system (CNS), opening new avenues for practical, and non-invasive gene therapy of neurological diseases. More recently, AAV of serotype rh10 (AAVrh10) was also found highly efficient to mediate CNS transduction after intravenous administration in mice. However, only a few studies compared AAV9 and AAVrh10 efficiencies, particularly in the spinal cord. In this study, we compared the transduction capabilities of AAV9 and AAVrh10 in the brain, the spinal cord, and the peripheral nervous system (PNS) after intravenous delivery in neonatal mice. As reported in previous studies, AAVrh10 achieved either similar or higher transduction than AAV9 in all the examined brain regions. The superiority of AAVrh10 over AAV9 appeared statistically significant only in the medulla and the cerebellum, but a clear trend was also observed in other structures like the hippocampus or the cortex. In contrast to previous studies, we found that AAVrh10 was more efficient than AAV9 for transduction of the dorsal spinal cord and the lower motor neurons (MNs). However, differences between the two serotypes appeared mainly significant at low dose, and surprisingly, increasing the dose did not improve AAVrh10 distribution in the spinal cord, in contrary to AAV9. Similar dose-related differences between transduction efficiency of the two serotypes were also observed in the sciatic nerve. These findings suggest differences in the transduction mechanisms of these two serotypes, which both hold great promise for gene therapy of neurological diseases.

Highlights

Nervous system diseases, including functional and degenerative disorders, can affect all cell types in the central (CNS) and peripheral (PNS) nervous system, leading to severe disabilities and patient death in the most severe cases
Intravenous adenoassociated virus (AAV) of serotype rh10 (AAVrh10) Provides a Similar or Higher Brain Transduction Level than associated-virus vector of serotype 9 (AAV9) Newborn mice were injected at P0 into the superficial temporal vein with the AAV9-GFP (n = 4) or AAVrh10-GFP (n = 4) vectors (3 × 1013 vg/kg), and transduction efficiency was first compared in the brain by immunofluorescence analysis 1 month after injection
In all the examined regions, a similar or higher level of transduction was observed with AAVrh10 compared to AAV9, AAVrh10 providing the greatest levels of expression in the cerebellar Purkinje cells, the vestibular and spinal trigeminal nuclei of the medulla, the lateral habenular nucleus, and the deep cortical layers (Figure 1)

Summary

Introduction

Nervous system diseases, including functional and degenerative disorders, can affect all cell types in the central (CNS) and peripheral (PNS) nervous system, leading to severe disabilities and patient death in the most severe cases. The comparison of single-stranded and self-complementary AAV of serotype 1 and 9 for transduction of the mouse CNS after IV delivery showed that self-complementary AAV9 was the most efficient vector for transducing spinal cord cells including motor neurons (MNs), and that transgene expression lasted at least 5 months (the duration of the study) (Duqué et al, 2009) This finding was successfully translated to a domestic cat strain with deletions of the LIX1 gene (Fyfe et al, 2006), a model of autosomal recessive spinal muscular atrophy (SMA) similar to human type III SMA (Duqué et al, 2009). Systemic AAV9 delivery was further shown to be very promising for treating other neurological or lysosomal diseases, including amyotrophic lateral sclerosis (Yamashita et al, 2013), Canavan disease (Ahmed et al, 2013) or MPSIIIA (Fu et al, 2011; Ruzo et al, 2012), highlighting the outstanding potential of this approach for a large range of CNS and systemic pathologies

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