Structural characterization of a novel human adeno-associated virus capsid with neurotropic properties

Abstract

Recombinant adeno-associated viruses (rAAVs) are currently considered the safest and most reliable gene delivery vehicles for human gene therapy. Three serotype capsids, AAV1, AAV2, and AAV9, have been approved for commercial use in patients, but they may not be suitable for all therapeutic contexts. Here, we describe a novel capsid identified in a human clinical sample by high-throughput, long-read sequencing. The capsid, which we have named AAVv66, shares high sequence similarity with AAV2. We demonstrate that compared to AAV2, AAVv66 exhibits enhanced production yields, virion stability, and CNS transduction. Unique structural properties of AAVv66 visualized by cryo-EM at 2.5-Å resolution, suggest that critical residues at the threefold protrusion and at the interface of the five-fold axis of symmetry likely contribute to the beneficial characteristics of AAVv66. Our findings underscore the potential of AAVv66 as a gene therapy vector.

POLR3-Related Leukodystrophy: Exploring Potential Therapeutic Approaches

“…Indeed, most AAV capsids are not known to efficiently transduce oligodendrocytes (Burger et al, 2004 ; Cearley and Wolfe, 2006 ; Cearley et al, 2008 ; San Sebastian et al, 2013 ). This fact has prompted studies evaluating the use of oligodendrocyte-specific promoters to drive expression in oligodendrocytes (Chen et al, 1998 ; Lawlor et al, 2009 ) as well as the pursuit of novel recombinant capsids with significant oligodendrocyte tropism as demonstrated in rodents (Powell et al, 2016 ), and the characterization of oligodendrocyte tropism in a novel naturally occurring AAV capsid (Hsu et al, 2020 ). Taken together, these study results indicate that AAV vector research continues to yield important advances toward achieving both safety and efficacy for in vivo gene therapy approaches to leukodystrophies.…”

Anion-exchange HPLC assay for separation and quantification of empty and full capsids in multiple adeno-associated virus serotypes

“…This may be due to overall differences in amino acid composition, resulting in varying capsid surface charge profile and overall structural characteristics of different AAV serotypes. 30,31 As a proof-of-concept study, commercially available or in-house produced samples or mixtures corresponding to five different AAV serotypes (AAV1, AAV2, AAV3, AAV8, and AAV9) were selected. When analyzed by AEX-HPLC using linear separation gradient of 0%-50% buffer B, all samples from different serotypes showed two distinct peaks with considerable overlap as seen with AAV6 (Figure S2).…”

Beyond the Traditional Clinical Trials for Amyotrophic Lateral Sclerosis and The Future Impact of Gene Therapy

“…In the past few years, brain-derived neurotrophic factor (BDNF), glial cell line derived neurotrophic factor (GDNF), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor (VEGF), Neuregulin 1 and Neurturin were used to treat ALS under pre-clinical settings [92,[96][97][98]. Different studies showed that AAV mediated expression of these neurotrophic factors delayed disease onset and prolonged survival in SOD1 mice model [96][97][98][99][100][101][102].…”

“…Overall, the increasing number of pre-clinical studies in non-human primates (NHP) and the generation of novel AAV vectors, more efficient in targeting CNS cells [ 87 ], will help assessing the best method for gene therapy delivery to ALS patients. Several other parameters will have to be considered to move forward the field, such as the long-term transgene expression, which produces sustained expression of silencing molecules.…”