Axonal transport of AAV9 in nonhuman primate brain

• Published in: Gene therapy Vol. 23; no. 6; pp. 520 - 526
• Main Authors: Green, F, Samaranch, L, Zhang, H S, Manning-Bog, A, Meyer, K, Forsayeth, J, Bankiewicz, K S
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-06-2016; Nature Publishing Group
• Subjects: 631/1647/1513; 631/378; Adeno-associated virus; Adenoviruses; Animals; Anterograde transport; Antigen presentation; Antigen-presenting cells; Antigen-Presenting Cells - metabolism; Astrocytes - metabolism; Astrocytes - virology; Axonal transport; Axonal Transport - genetics; Axonal Transport - physiology; Biological transport; Biomedical and Life Sciences; Biomedicine; Brain - metabolism; Brain - virology; Care and treatment; Cell Biology; Corpus Striatum - metabolism; Corpus Striatum - virology; Dependovirus - genetics; Dependovirus - metabolism; Dependoviruses; Dopamine receptors; Gene Expression; Gene Therapy; Genetic aspects; Genetic Therapy - methods; Genetic Vectors - genetics; Green fluorescent protein; Green Fluorescent Proteins - biosynthesis; Green Fluorescent Proteins - genetics; Human Genetics; Immunotoxicity; Macaca mulatta; Magnetic resonance imaging; Methods; Microglia - metabolism; Microglia - virology; Monkeys & apes; Nanotechnology; Nervous system diseases; Neurological diseases; Neurons - metabolism; Neurons - virology; original-article; Pilot Projects; Primates; Proteins; Putamen; Putamen - metabolism; Putamen - virology; Retrograde transport; Sexually transmitted diseases; STD; Substantia nigra; Substantia Nigra - metabolism; Substantia Nigra - virology; Substantia nigra pars reticulata; Thalamus; Transduction, Genetic - methods
• ISSN: 0969-7128; 1476-5462
• DOI: 10.1038/gt.2016.24

A pilot study in nonhuman primates was conducted, in which two Rhesus macaques received bilateral parenchymal infusions of adeno-associated virus serotype 9 encoding green fluorescent protein (AAV9-GFP) into each putamen. The post-surgical in-life was restricted to 3 weeks in order to minimize immunotoxicity expected to arise from expression of GFP in antigen-presenting cells. Three main findings emerged from this work. First, the volume over which AAV9 expression was distributed (Ve) was substantially greater than the volume of distribution of MRI signal (Vd). This stands in contrast with Ve/Vd ratio of rAAV2, which is lower under similar conditions. Second, post-mortem analysis revealed expression of GFP in thalamic and cortical neurons as well as dopaminergic neurons projecting from substantia nigra pars compacta, indicating retrograde transport of AAV9. However, fibers in the substantia nigra pars reticulata, a region that receives projections from putamen, also stained for GFP, indicating anterograde transport of AAV9 as well. Finally, one hemisphere received a 10-fold lower dose of vector compared with the contralateral hemisphere (1.5 × 10
13
vg ml
−1
) and we observed a much stronger dose effect on anterograde-linked than on retrograde-linked structures. These data suggest that AAV9 can be axonally transported bi-directionally in the primate brain. This has obvious implications to the clinical developing of therapies for neurological disorders like Huntington’s or Alzheimer’s diseases.