The vector technology – known as CHOGUN – was developed as a means of introducing genetic materials – including genes for therapeutic proteins - into CHO cells that lack the gene encoding the enzyme glutamine synthetase (GS).
The vectors are composed of a gene of interest and a copy of the GS gene.
GS Null CHO cells that successfully take up the vector express both genes, which means they can be identified based on their ability to make the amino acid glutamine.
The ability to make glutamine is an established means of selecting cells.
The most common approach is to use the GS inhibitor methionine sulphoximine, which suppresses the enzymes activity. As a result only cells that express the GS gene – and any vectors they have also taken up – at a sufficiently high rate survive the selection process.
The problem is that methionine sulphoximine is toxic, which means it must be removed during product purification. Such processing significantly increases production costs.
Proteonic co-founder Victor Schut told us the CHOGUN vectors were created to make methionine sulphoximine-based selection unnecessary, explaining the “vector has been developed specifically for GS selection and the Horizon GS knock out cell line.”
“ProteoNic expect that the partnership will provide biotechnology and pharma companies a strong alternative to existing GS systems in the market at very competitive and attractive terms and are looking to see a fast uptake of this platform in the coming year and 2017.”
Schut also said, as a result of the Horizon agreement, biopharmaceutical companies – including producers of “economics driven biosimilars” - will have the opportunity to test and license ProteoNic’s ProteoNic 2GUN vectors.
The firm's technology has already been licensed by US contractor Aragen Bioscience, which is using it to increase yields.