We generate stable cell lines you can count on
Our GPEx® technology is a proprietary, pseudo-typed, high-titer vector that generates stable mammalian cell lines - in record time. Virtually any cDNA (mAb and multigenic applications) can be packaged into the GPEx® retrovector and used to transduce your choice of mammalian cell line. To date, over 200 different mAb and mAb fusions and over 50 different recombinant proteins have been produced using the GPEx® system.
Case Studies of Success Utilizing GPEx Technology
- Cost- and time-effective
- Because of its reliability, GPEx® technology can reduce your overall expenses by cutting development time by more than half.
- Using conventional gene insertion and expression techniques, the development of a stable production cell line for a target protein can take as long as 18 months.
- In contrast, GPEx® technology can deliver a stable production cell line for your target protein in as little as 4.5 months.
- High-producing stable cell lines suitable for Master Cell Banking (MCB) and subsequent cGMP production are typically obtained in less than 5 months after receipt of your cDNA.
- Reliable and precise
- What sets our GPEx® technology apart from traditional methods is its spot-on reliability.
- By ensuring that stable transductions occur in virtually 100% of target cells (any mammalian cell line), GPEx® technology eliminates the need for selectable markers.
- In contrast, conventional transfection or electroporation methods produce an insertion frequency as low as 1 out of every 100,000 cells, thus necessitating additional selection steps and selectable marker genes.
- Other methods carry the risk of gene excision or silencing, making them relatively unstable.
- Higher yields
- The GPEx® gene insertion technology produces mammalian cell lines - typically CHO cells - that deliver higher initial yields of proteins than any conventional system based on transfection or electroporation. Here are two reasons why:
- The GPEx® retrovector targets high-expressing, chromosomal matrix attachment sites in the target cell genome; this leads to markedly higher expression of the gene in transduced cells compared with other systems.
- The optimization of GPEx® cell lines employs an iterative insertion process that drives up the inserted gene copy number and proportionally increases protein expression levels. As a result, the optimized cell line may have a dozen or more copies of the desired gene, all stably inserted and expressing the target protein.
- Better flexibility
- With better flexibility and unmatched versatility, GPEx® technology allows for a wide range of cell types to be used.
- Monoclonal antibody heavy- and light-chain coexpression
- Receptors coexpressed with a secreted surrogate
- Inactive proteins coexpressed with associated processing enzymes
- Sequential transduction used to introduce required genes without antibiotic selection
- Expressions enhanced by clonal selection or additional rounds of transduction without antibiotic selection
How It Works
- Retrovector technology
- GPEx® technology uses a retrovector technology that ensures the stable transduction of targeted cells, approaching 100% efficiency. This level of efficiency eliminates the requirement for selectable markers - something conventional methods must use during selection and gene amplification.
- IgGmAb Expression
- GPEx® technology expresses all types of IgGmAb: full-length mAbs, Fab fragments, chimeric antibodies, antibody fusion proteins and single-chain antibodies. Variable regions can be inserted into our retrovectors for cell line development and protein production.
- Backbone vectors
- GPEx® technology maintains backbone vectors containing the gamma constant region for human IgGs 1, 2, 3, and 4 and light-chain kappa and lambda constant regions as well as others. DNA sequences encoding IgG variable regions can be fused to any constant region in the GPEx® retrovector system. Using this system, we can produce virtually any desired IgG molecule. The technology can be applied to any mammalian cell line or used with in-house Master Cell Banked CHO parental cell line.
- Feasibility studies
- Reflecting your product development plan and leading to cell bank production, cell culture manufacturing, and purification process development
- Cell line
- Initial protein product in four months and MCB candidate in 4.5 months
- Process development
- Cell line optimization and gram-scale production and purification from small bioreactors
- cGMP manufacturing
- Phase I/Phase II cGMP production of clinical trial material
- Manufacturing capabilities of cGMP product for Phase I/Phase II clinical trials at our Madison, Wisconsin facility