Genetic Engineering & Biotechnology News

JAN15 2018

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0 1 2 3 4 5 6 7 8 0 50 100 CHO-S cell growth in ActiCHO media V iable cell density (10^6 cell/mL) Genetic Engineering & Biotechnology News | GENengnews.com | JANUARY 15, 2018 | 19 nonviral, insect cell–based, protein-expres- sion platform. ExpreS2 can produce com- plex proteins at very high yields and quality with uniformity of glycosylation and excel- lent protein folding. The platform consists of Drosophila melanogaster S2 cells, expres- sion vectors for stable integration into the genome, and transfection reagent, enabling rapid production of recombinant proteins for in vitro and in vivo use, with a typical timeline of 3–4 weeks from DNA to purified protein (Figure 2). S2 cells proliferate in suspension, reach- ing densities of 30–350 million cells/mL in shake flasks. Also, these cells are compatible with batch, fed-batch, and perfusion pro- duction modes. Frozen recombinant cells recover quickly, for on-demand, reproduc- ible production of proteins within one week from thawing the cells. "The ExpreS2 platform has been used in the production of more than 250 different proteins, even in cases where other expres- sion systems have failed," says Teit Max Moscote Soegaard, Ph.D., director of process development, Expres2ion Biotechnologies. "Products have been approved by regu- latory authorities in Europe and the United States, and some are currently running in Phase I/IIa trials, including two malaria vac- cine candidates—a pregnancy-associated malaria vaccine developed by Copenhagen University, and a blood-stage vaccine devel- oped by Oxford University." Unlike the lytic baculovirus expression vector systems (BEVs), the ExpreS2 platform relies on virus-free transfection and genomic integration followed by selection of stable polyclonal pools, or a monoclonal cell line. The protein of interest is secreted to the cell supernatant. Product secretion simplifies product harvesting and purification, and for VLP production, it has no baculovirus contamination. Secretion of fully processed viral glycoproteins in other systems (such as CHO systems) often requires overexpression of Furin protease to achieve the same level of homogeneity. This provides batch-to-batch reproduc- ibility and cultivation options, such as per- fusion systems for high yield/reduced cost. Cell and process robustness facilitates the transfer to GMP facilities for manufactur- ing, decreases process transfer time, and lowers the risk of batch failure/rejection. Lytic systems, such as BEVs, have significant issues with proteolysis of the protein of in- terest, as well as instability of the viral stock over time. ExpreS2ion and NextGen, a spin-out from the University of Copenhagen, recently formed AdaptVac, a joint venture company focused on expediting the development of plug-and-play vaccines. AdaptVac says that it utilizes the split-protein conjugation system to generate stable isopeptide-bound antigen- VLP complexes by simply mixing of the an- tigen and VLP components. That is, simple click-on chemistry is used to display antigens on the surface of generic VLPs. Compared with single-antigen presenta- tion, the multiple presentation of the antigen on this VLP platform, which in itself is highly immunogenic, elicits stronger and longer-last- ing immune responses than traditional sub- unit vaccines. This provides the ability to effi- ciently break self-tolerance, which is required for targeting human tumor suppressor pro- teins. A recent paper 1 presents very promising data constituting proof-of-concept-in-animals of a vaccine candidate for HER2-positive breast cancer in an advanced humanized mouse model of breast cancer. Reference 1. A. Palladini et al. "Virus-Like Particle Display of HER2 Induces Potent Anti-Cancer Responses," OncoImmunology (November 29, 2017), doi:10.1080/2162402X.2017.1408749. 0 1 2 3 4 5 6 7 8 0 50 100 CHO-S cell growth in ActiCHO media Viable cell density (10^6 cell/mL) Viability (%) 50 h 100 h 150 h 0.0 2.5 5.0 7.5 10.0 12.5 15.0 0 50 100 CHO-S cell growth in CD CHO media Viable cell density (10^6 cell/mL) Viability (%) 50 h 100 h 150 h 0.0 2.5 5.0 7.5 10.0 12.5 15.0 0 50 100 CHO-S cell growth in FortiCHO media Viable cell density (10^6 cell/mL) Viability (%) 50 h 100 h 150 h 0 m g/L In su lin 5 m g/L In su lin 1 m g/L In su lin 1 m g/L In su lin 0 m g/L In su lin 5 m g/L In su lin CHO cells are one of the most widely used platforms for the production of biopharmaceuticals. Increased demand for safety and reliability has moved the standard for CHO cell culture media from Serum to Serum free and further on to chemically defi ned media. UAB in collaboration with Novo Nordisk Pharmatech (world's largest supplier of recombinant insulin) has shown that addition of animal origin free insulin to three leading commercially available off-the-shelf chemically defi ned media resulted in signifi cant increases in viable cell density. In addition to this benefi t insulin has been proven to aid in the expression of diffi cult to express proteins. To learn more visit www.novonordiskpharmatech.com Increase viable CHO cell density by supplementation with recombinant Insulin Human AF Consistency. Proven CD CHO and CD FortiCHO are trademarks of Thermo Fisher Scientifi c and ActiCHO are trademarks of GE Healthcare Biosciences AB. Bioprocessing Figure 2. ExpreS2 is a nonviral, insect cell–based, protein- expression platform. It is being used to produce two malaria vaccine candidates— a pregnancy-associated malaria vaccine developed by Copenhagen University, and a blood-stage vaccine developed by Oxford University. ExpreS2ion Biotechnologies

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