In vivoselection in non-human primates identifies superior AAV capsids for on-target CSF delivery to spinal cord

• DOI: 10.1101/2023.09.13.557506
• Publication Date: 2023-09-14T15:04:54Z
• Authors: Killian S. Hanlon; Ming Cheng; Demitri De La Cruz; Nikita Patel; Miguel C. Santoscoy; Yi Gong; Carrie Ng; Diane M. Nguyen; Josette Nammour; Sean W. Clark; Karen Kozarsky; Casey A. Maguire
• Keywords: Biodistribution; Adeno-associated virus; Biopanning

Abstract Systemic administration of adeno-associated virus (AAV) vectors for spinal cord gene therapy has challenges including toxicity at high doses and pre-existing immunity that reduces efficacy. Intrathecal delivery AAV into the cerebral fluid (CSF) can avoid many issues systemic delivery, although achieving broad distribution vector transgene expression throughout is challenging entry to periphery occurs, sometimes initiating hepatotoxicity. Here we performed two rounds in vivo biopanning non-human primates (NHPs) with an AAV9 peptide display library injected intrathecally insert sequencing on DNA isolated from either whole tissue (conventional selection), nuclei, or nuclei transgene-expressing cells. A subsequent barcoded pool candidates was compared (biodistribution) RNA (expression) level liver NHPs. Most displayed enhanced biodistribution all levels ranging 2 265-fold. Nuclear isolation expression-based selection yielded 4 7 candidate capsids (up 2.4-fold), while no capsid obtained by conventional achieved level. Furthermore, several lower up 1,250-fold, AAV9, providing a remarkable target/off target ratio. These may have potential programs directed method described here should be useful clinically relevant large animal models.