Name: Video: Lateral Tail-Vein Injection for Systemic Therapeutic Delivery of Adeno-Associated Virus in Mice
Uploaded: 2024-08-23T13:10:00
Duration: 4 min 4 s
Description: 214 Views. Lateral Tail-Vein Injection for Systemic Therapeutic Delivery of Adeno-Associated Virus in Mice

lateral tail-vein injection for systemic therapeutic delivery of adeno-associated virus in mice

AAV-Based Therapies via Intravenous Injection in Preclinical Mouse Models

Monogenic disorders make up 80% of rare diseases, which collectively affect 300 million individuals worldwide1,2. There are currently no approved curative therapies for the majority of these greatly debilitating rare disorders1,2,3. However, monogenic disorders are ideal candidates for gene therapies that can replace, supplement, correct, or silence dysfunctional genes4,5. Currently, multiple vectors are being developed and used to deliver gene therapies to specific cell types4,6. One of those vectors is adeno-associated virus (AAV). AAV is a non-pathogenic parvovirus that is increasingly being used as a gene therapy vector7. Compared to other viral vectors, AAV has lower immunogenicity, lower potential to integrate into the host genome, and the ability to efficiently transduce dividing and non-dividing cells in various tissues7,8. Additionally, multiple approaches have been developed to engineer and identify AAVs with desirable characteristics such as specific tissue tropism or further reduced immunogenicity, which greatly enhances AAV&#39;s versatility as a viral vector for different indications9. These factors have made AAV a widely investigated gene therapy vector and led to the development of multiple FDA-approved AAV-based gene therapies10.
Mouse models are commonly used to test potential gene therapies in vivo and better understand the pathomechanisms of monogenic disorders. This is due to the mouse models&#39; recapitulation of the pathologies of different conditions, their genome&#39;s similarity to the human genome, and the relative ease of mouse handling, maintenance, and generation11,12,13. In vivo testing is particularly important when studying disorders that affect multiple systems or regions of the body, such as muscular dystrophies. For these disorders, in vitro testing might not be sufficient to comprehensively assess the safety, efficacy, pharmacokinetics, and pharmacodynamics of therapeutics intended to reach different body regions after systemic administration14.
Various systemic administration routes can be used to deliver drugs. Each route has its advantages, drawbacks, and degree of compatibility with the animal model and drug being investigated15. Intravenous (IV) lateral tail-vein injection is a commonly used route for systemic delivery of AAV in mice16. Lateral tail-vein injections allow fast and direct administration of the injectate into the mouse bloodstream ensuring high drug bioavailability in systemic circulation17. They also require relatively simple and commonly available tools to be performed. However, mainly due to the small tail vein diameter and difficulty in locating the vein, lateral tail-vein injections are technically challenging and require a high degree of skill and constant practice to avoid failed injection attempts or incomplete dose delivery16,17,18,19. These can result in the loss of expensive reagents or inaccurate results, especially if the incomplete injection is not recognized while performing the injection. Our experience summarized here is based on protocols reported in well-documented articles that we have adapted for our use, optimizing various steps of the lateral tail-vein injection procedure to ensure consistently successful injections20,21,22,23,24,25,26,27.
Here, we describe this detailed optimized lateral tail-vein injection protocol to deliver AAV into unsedated 7-9-week-old mice using simple and commonly available tools. Additionally, we provide the protocols for methods used to assess AAV delivery and biodistribution. These protocols cover post injection tissue collection, tissue fixation, DNA extraction, and digital polymerase chain reaction (dPCR) vector genome per diploid genome (vg/dg) quantification. The IV injection protocol and pointers provided here aim to enhance the ease of successfully performing lateral tail-vein injections. This will potentially help reduce the time needed to master the injection skills while simultaneously improving the accuracy and consistency of injections.

Author Spotlight: Developing Gene Therapies for Muscular Dystrophies and Neuromuscular Disorders

Consistent Delivery of Adeno-Associated Virus via Lateral Tail-Vein Injection in Adult Mice

Lateral Tail-Vein Injection for Systemic Therapeutic Delivery of Adeno-Associated Virus in Mice

lateral-tail-vein-injection-for-systemic-therapeutic-delivery-adeno

Research

JoVE Journal

Medicine

214 Views. Lateral Tail-Vein Injection for Systemic Therapeutic Delivery of Adeno-Associated Virus in Mice

Video: Lateral Tail-Vein Injection for Systemic Therapeutic Delivery of Adeno-Associated Virus in Mice

Many disorders affect multiple organs or involve different regions of the body, so it is critical to deliver therapeutics systemically to target the affected cells located in different sites. Intravenous injection is a widely used systemic delivery route in preclinical studies that assess treatments intended for body-wide administration. In adult mice, it involves the intravenous administration of the therapeutic agent into the mouse&#39;s lateral tail veins. When mastered, tail-vein injections are safe and fast, and only require simple and commonly available tools. However, tail-vein injections are technically challenging and require extensive training and continuous practice to ensure the accurate delivery of the intended dose.
Here we describe a detailed, optimized, lateral tail-vein injection protocol that we have developed based on our experience and on recommendations that had been previously reported by other groups. Other than the mouse restrainers and insulin syringes, this protocol requires only reagents and equipment that are readily available in most labs. We found that following this protocol results in consistently successful intravenous delivery of adeno-associated virus (AAV) into the tail veins of unsedated 7-9 week-old mice. Additionally, we describe the optimized protocols for the histological detection of fluorescent reporter proteins and vector genome per diploid genome (vg/dg) quantification used to assess AAV transduction and biodistribution. The goal of this protocol is to aid experimenters in easily performing tail-vein injections successfully and consistently, which can reduce the practice time needed to master the technique.

Here we detail an optimized protocol for mouse lateral tail-vein injection to systemically administer adeno-associated virus (AAV) in adult mice. Additionally, we describe protocols of commonly used assays to assess AAV transduction.

Many disorders affect multiple organs or involve different regions of the body, so it is critical to deliver therapeutics systemically to target the ...