Hardwiring tissue-specific AAV transduction in mice through engineered receptor expression

Abstract

The development of transgenic mouse models that express genes of interest in specific cell types has transformed our understanding of basic biology and disease. However, generating these models is time- and resource-intensive. Here we describe a model system, SELective Expression and Controlled Transduction In Vivo (SELECTIV), that enables efficient and specific expression of transgenes by coupling adeno-associated virus (AAV) vectors with Cre-inducible overexpression of the multi-serotype AAV receptor, AAVR. We demonstrate that transgenic AAVR overexpression greatly increases the efficiency of transduction of many diverse cell types, including muscle stem cells, which are normally refractory to AAV transduction. Superior specificity is achieved by combining Cre-mediated AAVR overexpression with whole-body knockout of endogenous Aavr, which is demonstrated in heart cardiomyocytes, liver hepatocytes and cholinergic neurons. The enhanced efficacy and exquisite specificity of SELECTIV has broad utility in development of new mouse model systems and expands the use of AAV for gene delivery in vivo.

Predicted deleterious variants in the human genome relevant to gene therapy with adeno-associated virus vectors

“…A recent report described a transgenic mouse with cre-inducible over-expression of the AAVR. 38 This strain allowed tissue tropism of AAV gene transfer to be manipulated by selective activation of AAVR expression. That model is consistent with our hypothesis, i.e., that a naturally occurring polymorphism that affects AAVR expression level could modified the efficiency of AAV transduction in vivo .…”

PET imaging of focused-ultrasound enhanced delivery of AAVs into the murine brain

“…Intracranial injection has been employed for AAV delivery into the brain, as it allows for precise targeting of specific brain regions; however, this technique is invasive and there is a potential risk of tissue damage and adverse effects [34]. We have previously explored the biodistribution and pharmacokinetics of AAVs in wild type mice without ultrasound in three papers [19][20][21]. The offtarget biodistribution is not significantly changed by the application of ultrasound to a small region of the brain as demonstrated by PET imaging and ROI quantification (Supplementary Fig.…”

“…Historically, uptake and protein expression of AAVs locally delivered into the brain using FUS have been assessed using invasive techniques 12 . In our previous work, AAVs radiolabeled with trace amounts of a positron emitter enabled non-invasive tracking of AAV capsids through in vivo imaging with positron emission tomography (PET) 19 and further allowed us to evaluate the receptor for AAV9 through tracking of AAVs in transgenic mice 20 . AAV capsids with a PET imaging tag and reporter gene facilitated a non-invasive comparison of localization and transduction in the mouse brain and liver 21 .…”

Chemical approaches to probe and engineer AAV vectors

“…This strategy has also been used to introduce other probes such as quantum dots, which are less susceptible to photobleaching, as well as radioactive isotopes (which was attached to AAV by NHS-tetrazine, followed by TCO ligation), enabling other ways to probe AAV entry and trafficking. 78–81…”