Protein expression and production in mammalian cells
Instruct has 5 centres offering Mammalian expression across Europe. Navigate the map and click on the pins to discover centres near you.
Production of functional mammalian proteins in prokaryotic or insect cells can be hindered by the lack of the correct folding machinery and post translational modifications. To overcome this problem the mammalian expression platform proposes to express intra cellular and secreted proteins and protein complexes in several mammalian cell lines with a number of expressions systems. In addition to the commercially available expression vectors, specific expressions systems developed on the platform will be available to the user. The platform will offer a facility with two levels of complexity. The first level will be to produce recombinant proteins with vectors provided by the user. The second level will be the construction and screening of several expression vectors to optimize the production of functional and soluble protein and protein complexes.
Large scale biomass production
The Instruct facility also supports the routine production of recombinant mammalian proteins by mammalian cell lines or the Baculovirus system in 50 L scale. Both secreted as well as intracellular proteins can be produced in up to 200 L of cell culture by a perfusion process or semi-continuous fermentation.
Stable CHO cell line development by RMCE
A unique and fast method to create stable, glycosylation mutant CHO production cell lines using a high producer master cell line and site specific recombination allows faster access to difficult to express mammalian glycoproteins (Wilke et al., Protein Science, Prot Science 19 (2010), p1264). The method is based on cloning a gene of interest into an exchange vector and subsequent specific integration of the expression cassette into a preselected high producer master cell line. The resulting production cell lines can be generated in two to four months, which is substantially faster than by classical integration techniques. The resulting cell lines allow the production of mg amounts of mammalian protein. The performance and stability of new producer cell lines has been tested in batch and continuous fermentation. This strategy increases the throughput of producing difficult target proteins in the mammalian stable CHO expression system.
The strategy for protein expression in mammalian cells is the transfection with plasmid vectors or infection with viral vectors (inducible or constitutive) of cell culture (adherent or suspension). The platform will perform cell cultures ready for transfection or infection with the vector carrying the recombinant gene provided by the user. In a second step, the platform will propose a set of expression vectors (commercial or developed on site) to be screened together with cell type for the optimization of functional and soluble protein and protein complexes production.