AAV Episomal Persistence Evaluation Service
Episomal adeno-associated virus (AAV) vectors are those AAV genomes yet integrated into the chromosome of transduced cells. Evaluation of the episomal persistence of AAV vectors will provide guidance for further gene therapy. Based on well-constructed gene therapy platform, Creative Biolabs is proud to offer a broad spectrum of AAV design and evaluation services to the universal clients.
Introduction of AAV Episome
AAV plays an increasingly important role in gene therapy since its obvious advantages, including non-toxicity, high transfection efficiency, low immunogenicity and so forth. As early as 2012, the first recombinant AAV gene therapy product was approved for the treatment of lipoprotein lipase deficiency by the European Medicines Agency (EMA). Since then, numbers of AAV-based gene therapy products have been developed for various disease therapies.
Usually, AAV vectors transfer target genes by integrating into the genome of the host cells at a location on the long arm of chromosome 19 in a specific site manner, in which the integration is mediated by the Rep gene in AAV. By removal of the Rep from the DNA of the vector, recombinant AAV vector can not integrate into the chromosome, which results in the formation of AAV episome in the nucleus of transduced cells. AAV vector functions in both integrated and episomal forms displaying respective advantages and limitations.
Figure 1. Steps of recombinant adeno-associated virus transduction and the potential impact of the aged brain environment. (Polinski, 2015)
Service
For those non-integrated AAV vectors, the transferred genes persist predominantly as episomal monomeric or concatemeric circles in the nucleus of infected cells. In quiescent cells, such as rodent muscle cells and non-human primate myocytes, episomal AAV and the stable transgene expression are observed with long periods of time. These episomal vectors are important for clinical applications, which can express therapeutic genes without changing the genome in host cells. However, in dividing cells such as epithelial cells and tumor cells, the episomal AAV would be gradually diluted even lost over the repeated rounds of cell division since the genome can not replicate along with the host cells' DNA. This episomal AAV vector eventually leads to the loss of the transgene and decreased transfection efficiency.
To estimate the expression efficiency of the transgene and determine the initial dosage of vector-based gene therapy, Creative Biolabs at present provides comprehensive evaluation services for AAV episomal persistence after years of effort and experience.
Features
- Various of recombinant AAVs with high titer
- Cutting-edge viral vector technology
- One-stop customized services covering from diverse virus products to related applications
As a leading provider of gene therapy services, Creative Biolabs is wholehearted to provide diversiform of viral vector products and custom services based on the requirements of the clients. Besides AAV episomal persistence evaluation service, other services like AAV vector design, AAV vector purification, AAV vector characterization, etc. are also within the scope of our business.
We believe that our high-quality services will help you get through many thorny issues of AAV vector-based gene therapy. Please feel free to contact us for more details.
Reference
- Polinski, N.K.; et al. (2015). Recombinant adeno-associated virus 2/5-mediated gene transfer is reduced in the aged rat midbrain. Neurobiology of Aging. 36(2): 1110-1120.
