An innate immune response to adeno-associated virus genomes decreases cortical dendritic complexity and disrupts synaptic transmission

Christos M Suriano; Neerav Kumar; Jessica L Verpeut; Jie Ma; Caroline Jung; Connor E Dunn; Brigett V Carvajal; Ai Vy Nguyen; Lisa M Boulanger

doi:10.1016/j.ymthe.2024.03.036

An innate immune response to adeno-associated virus genomes decreases cortical dendritic complexity and disrupts synaptic transmission

Mol Ther. 2024 Apr 1:S1525-0016(24)00214-4. doi: 10.1016/j.ymthe.2024.03.036. Online ahead of print.

Authors

Christos M Suriano¹, Neerav Kumar², Jessica L Verpeut³, Jie Ma⁴, Caroline Jung³, Connor E Dunn², Brigett V Carvajal³, Ai Vy Nguyen³, Lisa M Boulanger⁵

Affiliations

¹ Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08540, USA; Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08540, USA; Department of Biology, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043, USA; Sokol Institute for Pharmaceutical Life Sciences, Montclair State University, 1 Normal Avenue, Montclair, NJ 07043, USA. Electronic address: surianoc@montclair.edu.
² Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08540, USA.
³ Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08540, USA.
⁴ Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08540, USA; Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08540, USA.
⁵ Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08540, USA; Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08540, USA. Electronic address: lboulang@princeton.edu.

PMID: 38566414
DOI: 10.1016/j.ymthe.2024.03.036

Abstract

Recombinant adeno-associated viruses (AAVs) allow rapid and efficient gene delivery to the nervous system, are widely used in neuroscience research, and are the basis of FDA-approved neuron-targeting gene therapies. Here we find that an innate immune response to the AAV genome reduces dendritic length and complexity and disrupts synaptic transmission in mouse somatosensory cortex. Dendritic loss is apparent 3 weeks after injection of experimentally relevant viral titers, is not restricted to a particular capsid serotype, transgene, promoter, or production facility, and cannot be explained by responses to surgery or transgene expression. AAV-associated dendritic loss is accompanied by a decrease in the frequency and amplitude of miniature excitatory postsynaptic currents and an increase in the proportion of GluA2-lacking, calcium-permeable AMPA receptors. The AAV genome is rich in unmethylated CpG DNA, which is recognized by the innate immunoreceptor Toll-like receptor 9 (TLR9), and acutely blocking TLR9 preserves dendritic complexity and AMPA receptor subunit composition in AAV-injected mice. These results reveal unexpected impacts of an immune response to the AAV genome on neuronal structure and function and identify approaches to improve the safety and efficacy of AAV-mediated gene delivery in the nervous system.

Keywords: AAV; Toll-like receptor 9; dendritic arbor; neuron; synaptic communication.