A brain microvasculature endothelial cell‐specific viral vector with the potential to treat neurovascular and neurological diseases

Abstract

Gene therapy critically relies on vectors that combine high transduction efficiency with a high degree of target specificity and that can be administered through a safe intravenous route. The lack of suitable vectors, especially for gene therapy of brain disorders, represents a major obstacle. Therefore, we applied an in vivo screening system of random ligand libraries displayed on adeno‐associated viral capsids to select brain‐targeted vectors for the treatment of neurovascular diseases. We identified a capsid variant showing an unprecedented degree of specificity and long‐lasting transduction efficiency for brain microvasculature endothelial cells as the primary target of selection. A therapeutic vector based on this selected viral capsid was used to markedly attenuate the severe cerebrovascular pathology of mice with incontinentia pigmenti after a single intravenous injection. Furthermore, the versatility of this selection system will make it possible to select ligands for additional in vivo targets without requiring previous identification of potential target‐specific receptors.

Gene therapy decreases seizures in a model of Incontinentia pigmenti

“…6 Recombinant AAV vectors were produced by triple transfection of HEK293T cells. The plasmids pAAV-CAG-NEMO-2A-eGFP and pAAV-CAG-eGFP were generated as previously described.…”

“…6 The new AAV-BR1 vector shows unprecedented specificity for the brain endothelium and low transduction of the liver or other easily accessible peripheral organs after intravenous injection. This aim came within reach when a novel strategy of in vivo screening led to a suitable adeno-associated virus (AAV) 2-based vector with mutated capsid.…”

Vascular-targeted recombinant adeno-associated viral vectors for the treatment of rare diseases

“…In our recent study published in EMBO Molecular Medicine, we could show that the screening of random AAV display peptide libraries is a promising technique to generate truly tailored vectors. 7 The production of recombinant AAV2 vectors displaying the brain-targeted NRGTEWD peptide (AAV-BR1) yields comparable virus amounts to unmodified wildtype AAV2 in repetitive experiments (in our hands in approx. 1x10 11 genomic particles from 1x10 7 HEK 293T cells after iodixanol purification).…”

“…5,6 In our recent study published in EMBO Molecular Medicine, we report on the generation of a novel recombinant AAV vector, termed AAV-BR1, which specifically targets the brain and the spinal cord where it predominantly transduces blood-brain barrier (BBB)-associated endothelial cells after intravenous injection in mice. 7 Several systems have been developed and employed to generate AAV vectors with improved tropism, but only very few vectors have been proven to really be suited for systemic target-specific gene therapy.…”

MRI-Guided Focused Ultrasound for Targeted Delivery of rAAV to the Brain

“…Intravenous injections of rAAVs, with and without FUS, can lead to peripheral transduction, limiting CNS delivery and treatment efficacy and potentially generating adverse side effects. Strategies for mitigating peripheral rAAVs transduction [21] and expression [22] can be deployed as required.…”