Adeno-associated viruses (AAVs) are highly effective gene therapy vectors due to their harmless nature and ability to infect humans readily. In AAV-based gene therapy, there is a crucial need for accurate and precise AAV titer.
There is an urgent need for standardized quantification methods for AAV titer purposes. Developing and employing these standardized techniques across different laboratories and production systems is a central challenge in AAV-based gene therapy.
What are AAVs and how are they used?
AAVs are a group of viruses that infect primates and humans. These viruses are tiny, with a diameter of around 20 nm, and require the aid of other viruses to replicate.
Extremely simple viruses consisting of just a protein shell with a single-stranded DNA payload, they score low on the scale of virus complexity. AAVs induce a minor immune response in humans but are unknown to cause any disease.
AAVs are highly prevalent in humans, with around 50-80% exhibiting seropositivity for antibodies directed against AAV capsid proteins.1
Due to their qualities, AAV serotypes (especially AAV2) are outstanding gene therapy candidates. The use of AAVs in targeting genetic disorders and preventing disease by replacing faulty genes with healthy ones has become a central focus of genetic research in recent years.2
What is AAV titer?
AAVs have rapidly become one of the most actively investigated gene therapy vehicles over the past 20 years. Scientists have successfully employed recombinant AAVs as protein-based DNA delivery systems to treat several genetic conditions.
Accurate AAV titer and characterization are key to developing safe and effective AAV-based gene therapies.5 The need for efficient AAV vector manufacturing and downstream processing was highlighted by the commercial demise of the first EU-approved AAV-based gene therapy product.6
If the field of AAV-based gene therapy and disease treatment is to be fully realized in the near future, there is an urgent need to develop standardized methods that can effectively characterize and quantitate this class of viral vectors.
Challenges in AAV titer
Multiple methods have been developed and employed in recent years to improve genome titer and AAV quantitation. These include enzyme-linked immunosorbent assay (ELISA), quantitative polymerase chain reaction (qPCR), and high-pressure liquid chromatography (HPLC).7,8
There are some key drawbacks to these methods in terms of time consumption and a lack of standardized methods.9
AAV titer from Gator Bio
Gator Bio has developed a solution to overcome the current challenges with AAV quantitation. The company has developed high-specificity antibody-based biosensors for use as AAV probes.
The technological solutions offered by Gator Bio are highly accurate and possess a wide dynamic range of 109-1013 VP/mL for most AAV serotypes.
Faster and more efficient than time- and labor-intensive conventional techniques, such as ELISA, cost-effectiveness is enhanced by the probes’ crude sample tolerance and reusability.
AAV titer probes from Gator Bio are suitable for multiple-stage deployment in the development and manufacture of AAV-based gene therapies, providing significant benefits for researchers working in this field.
Contact the experts
Gator Bio is an industry-leading developer of BLI systems and solutions. To find out more about AAV titer solutions from Gator Bio, get in touch with an expert today.
References and further reading
- Grieger, J. C. & Samulski, R. J (2005). Adeno-associated Virus as a Gene Therapy Vector: Vector Development, Production and Clinical Applications. Gene Therapy and Gene Delivery Systems vol. 99 pp. 119–145
- Zinn, E. & Vandenberghe L. H. (2014) Adeno-associated virus: fit to serve. Curr Opin Virol 8, pp. 90–97
- Naso, M. F et al. (2017) Adeno-Associated Virus (AAV) as a Vector for Gene Therapy. BioDrugs 31, pp. 317–334
- How does gene therapy work?: MedlinePlus Genetics. https://medlineplus.gov/genetics/understanding/therapy/procedures/.
- Dobnik, D. et al. (2019)Accurate Quantification and Characterization of Adeno-Associated Viral Vectors. Front. Microbiol. 10, 1570
- Ai, J. et al. (2017) Scalable and Accurate Method for Quantifying Vector Genomes of Recombinant Adeno-Associated Viruses in Crude Lysate. Human Gene Therapy Methods 28, pp. 139–147
- D’Costa, S. et al. (2016) Practical utilization of recombinant AAV vector reference standards: focus on vector genomes titration by free ITR qPCR. Mol Ther Methods Clin Dev 5, 16019
- Dorange, F. & Le Bec, C. Analytical approaches to characterize AAV vector production & purification: Advances and challenges. Cell and Gene Therapy Insights 4, 119–129 (2018).
- Aucoin, M. G.et al. (2008) Critical assessment of current adeno-associated viral vector production and quantification methods. Biotechnology Advances 26, pp. 73–88
About Gator Bio, Inc.
Gator Bio is a world-leading biosensor company headquartered in Palo Alto, CA. At Gator Bio, we provide researchers the tools and instrumentation to advance their research. From antibody engineering to small molecule drug discovery to basic research, Gator Bio can be used to bring meaning to the unknown. From the original inventors of label-free biolayer interferometry (BLI), Gator Bio provides the next generation of BLI technology.
Sponsored Content Policy: News-Medical.net publishes articles and related content that may be derived from sources where we have existing commercial relationships, provided such content adds value to the core editorial ethos of News-Medical.Net which is to educate and inform site visitors interested in medical research, science, medical devices and treatments.