To produce large quantities of vaccines in a rapid and cost-effective way is the main challenge that the vaccine industry is facing. Major changes to current bioprocesses are difficult to implement due to costs associated with the regulatory approval process. Therefore, we propose to use insulin, a protein currently used and approved in several processes and production platforms, as an additive to boost cell growth and viral production.
The HEK293SF-3F6 cell line is a GMP cell line that has been adapted to growth in suspension in serum-free condition. In a commercially available media, the cell density was increased by four-fold upon addition of 10mg/L insulin. In a media formulated in-house, the growth was accelerated with insulin and we reached maximal cell density within 6 days instead of 10 days.
HEK293SF-3F6 cells constitute a permissive host for influenza viruses and several different strains have been produced. In order to improve production of viruses and viral vectors, the addition of increasing concentrations of insulin at different time points during the infection process has been examined in a microbioreactor. Traditional quantification methods used to titer influenza are variable and low-throughput. In this presentation, we will also describe an approach that allows rapid and robust quantification of multiple strains of influenza using universal antibodies in conjunction with a dot blot technique. When 25 to 100µg/ml insulin was added to the culture at the time of infection, the productivity of an H1N1 influenza strain was increased by nearly two-fold. This increase in production was accompanied by an activation of signaling pathways associated with cell survival. Results with an H3N2 strain will also be presented.