9 FAQs About Charles River’s Service Offerings
Charles River has been on the leading edge of supporting the development of novel therapeutics and has made extensive and growing contributions in supporting cell and gene therapy research. Below, they address some commonly asked questions regarding their most current service offerings.
1. What is the difference between a gene and cell therapy?
Both are considered an advanced therapeutic medicinal product, or ATMP. A gene therapy uses genetic material to modify the function of patient cells in the treatment of inherited or acquired disease. Genes are responsible for creating the proteins that control cellular processes. In many diseases, genetic instructions are missing or defective. Gene therapy seeks to replace a missing gene or to provide a normal copy of a mutated gene. Cell therapy involves the infusion or transplantation of whole cells (e.g., bone marrow transplant or CAR-T) and frequently involves prior modification of the cells by a viral vector.
2. What are viral vectors?
A viral vector is a gene therapy delivery system. One of the most common vector types is created from a virus called adeno-associated virus (AAV). This naturally occurring entity does not cause illness in people, and thus, the AAV vector is an ideal vehicle to transmit gene therapies to the body.
3. What are the most common viral vectors for gene therapies?
Typically, gene therapy development uses AAV), but the following viral vectors can also be used: retrovirus, lentivirus and adenovirus, which are all available at Charles River.
4. What are AAV reference materials full and empty capsids used for?
Full capsids can be used in qPCR-based vector genome qualification. Empty capsids are high quality and high purity and can be used as negative controls or reference materials in quality control assays, including HPLC, ELISA, etc. We offer well-characterized AAV reference materials that are needed for quality control assays and for bridging calibration of internal reference materials. Since AAV is known to produce empty particles without payloads, the full-to-empty ratio of standard materials is also very important for product characterization.
5. What types of AAV controls are available at Charles River?
Charles River offers AAV empty capsids in serotypes AAV1, AAV2, AAV6, AAV8 and AAV9. The AAV empty capsids are produced and purified using iodixanol gradient ultracentrifugation. We r also offer control AAVs expressing GFP or other payloads in multiple serotypes and with a range of promoters. The final quality control assays panel can include qPCR for titer, ELISA for titer, endotoxin assay, bioburden, SDS-PAGE, A260/280, HCP and HCD.
6. What AAV serotype should I use?
Tissue specificity is determined by the viral capsid proteins, so it is important to select the correct AAV serotype to ensure optimal gene delivery. The table below lists the recommended AAV serotypes for the different target tissues. If you are unsure which AAV serotype will work best for your system, we recommend that you try out our AAV GFP testing Kit. The testing kit contains the following viruses all driven by the strong CMV promoter: GFP AAV1, GFP AAV2, GFP AAV5, GFP AAV6, GFP AAV8, GFP AAV 9 and GFP AAV-DJ.
Muscle: AAV1, AAV6, AAV8, AAV9
Liver: AAV8, AAV9, AAV-DJ
Lung: AAV5, AAV6, AAV9
CNS: AAV1, AAV5, AAV8, AAV9, AAV-DJ
Retina: AAV1, AAV2, AAV5, AAV8
Kidney: AAV2, AAV9
Heart: AAV1, AAV8, AAV9
7. What volumes of packaging can be requested?
We offer a range of scales, each with differing purposes. Crude (small scale, 500 µL) unpurified preparations are suitable for feasibility and for construct screening. Routine packaging (500 µl – 1ml) is purified and is the typical size for in vitro experiments (gene-expression/efficacy). High titer (2mL to 100mL) are larger batches that are more highly purified, intended for use in smaller animal models. Finally, the pre-clinical offering is suitable for larger-scale animal models and/or potentially for toxicology studies.
8. Do I send plasmid or can Charles River make them?
If you have sufficient transgene plasmid amounts for transfection, we can utilize your supplied plasmid. If you have seed plasmid for your transgene but require plasmid amplification to support quantities necessary for transfection, Charles River has in-house plasmid amplification capabilities. We can also start with a gene sequence and perform cloning of your gene segment into one of our shuttle vectors for the creation of your transgene plasmid. Ask us how much plasmid is needed.
9. What other cell and gene services does Charles River provide?
Charles River offers full end-to-end support of cell and gene therapy product development. This starts with critical starting materials (plasmids, vectors and cell sourcing) and manufacturing capabilities from research through clinical grade. Charles River also provides research models and scientific and regulatory support for IND-enabling development and has full analytical development and QC testing capabilities for research through clinical-grade cell and gene therapy products.
About Charles River
For over 75 years, Charles River has provided essential products and services to help pharmaceutical and biotechnology companies, government agencies, and leading academic institutions around the globe, helping to accelerate their research and drug development efforts. With over 90 sites globally, we’re ready to tackle your product’s most unique challenges. Our focus on timeliness and accuracy in every stage of drug development means you can count on us to deliver reliable results – every step of the way.