Abstract: The invention concerns the field of cell culture technology. The invention describes production host cell lines comprising vector constructs comprising a DHFR expression cassette. Those cell lines have improved growth characteristics in comparison to DHFR-deficient or DHFR-reduced cell lines such as CHO DG44 and CHO DUKX-B11. The invention especially concerns two cell lines, a representative of each cell line is deposited with the DSMZ under the number DSM ACC2909 (CHOpper® Discovery) and DSM ACC2910 (CHOpper® Standard). The invention further concerns a method of producing proteins using the cells generated by the described method.

Abstract: The present invention concerns the field of cell culture technology. It describes a novel method for enhancing the secretory transport of proteins in eukaryotic cells by heterologous expression of Munc18c, Sly1 or other members of the SM protein family. This method is particularly useful for the generation of optimized host cell systems with enhanced production capacity for the expression and manufacture of recombinant protein products.

Abstract: Production of biopharmaceuticals from CHO cells requires generation of master-, working- and post-production cell banks of high quality, partly under GMP conditions. An optimal cryopreservation strategy is needed for each new production cell line, particularly with regard to the desire to establish production processes that are completely devoid of serum or even any animal components and to ensure robust thaw performance for reliable production. Here we describe a novel strategy employing flow cytometric (FC) analysis of Annexin V-stained cells for high-throughput characterization of CHO cell banks. Our data show that this method enables evaluation of a cryopreservation procedure just 6 h after thaw.

Abstract: The invention concerns the field of protein production and cell culture technology. CERT is identified as a novel in vivo PKD substrate. Phosphorylation on serine 132 by PKD decreases the affinity of CERT towards its lipid target phosphatidylinositol 4-phosphate at Golgi membranes and reduces ceramide transfer activity, identifying PKD as a regulator of lipid homeostasis. The present invention shows that CERT in turn is critical for PKD activation and PKD dependent protein cargo transport to the plasma membrane. The interdependence of PKD and CERT is thus a key to the maintenance of Golgi membrane integrity and secretory transport.

Abstract: The invention concerns the field of protein production and cell culture technology. CERT is identified as a novel in vivo PKD substrate. Phosphorylation on serine 132 by PKD decreases the affinity of CERT towards its lipid target phosphatidylinositol 4-phosphate at Golgi membranes and reduces ceramide transfer activity, identifying PKD as a regulator of lipid homeostasis. The present invention shows that CERT in turn is critical for PKD activation and PKD dependent protein cargo transport to the plasma membrane. The interdependence of PKD and CERT is thus a key to the maintenance of Golgi membrane integrity and secretory transport.

Abstract: The invention describes novel methods for selecting cell clones which produce high amounts of protein of interest. In one method the amount of protein is measured before the cells are passaged for the first time. In another method a high throughput automated platform is used under sterile environment conditions with class A particle load of less than 100 particles per m3.

Abstract: Production of biopharmaceuticals from CHO cells requires generation of master-, working- and post-production cell banks of high quality, partly under GMP conditions. An optimal cryopreservation strategy is needed for each new production cell line, particularly with regard to the desire to establish production processes that are completely devoid of serum or even any animal components and to ensure robust thaw performance for reliable production. Here we describe a novel strategy employing flow cytometric (FC) analysis of Annexin V-stained cells for high-throughput characterization of CHO cell banks. Our data show that this method enables evaluation of a cryopreservation procedure just 6 h after thaw.