Enhancing CHO by Systems Biotechnology

Abstract

Earlier this year in March we published the first part of this special issue series on "enhancing CHO by systems biotechnology" presenting 15 papers on this exciting topic to highlight the advances made in the field since the release of genome sequence information on CHO in 2011 [1] and on the Chinese Hamster in 2013. [2,3] With a new and much better assembled reference genome recently released, [4] we are on a good way to genome scale science for this important industrial cell line. In the current issue there will be another 14 papers, including seven coming from students of the EU Horizon 2020 Marie Curie Actions program of the same name (www.echo-systems.eu). These students also designed the cover image, outlining the network, and topics of their program.In this second issue, we find several papers on the CHO cell transcriptome, starting with a high level comparison of transcriptome data of CHO-S, CHO-K1, and DG44 cells by Singh et al., [5] revealing a higher level of expression for genes related to the Golgi, the endosomes, and vesicular transport in CHO-S, all known bottlenecks for high productivity and secretion of recombinant proteins. Tamosaitis and Smales [6] present a similar approach, where publicly available transcriptome data that can be connected to growth and productivity were analyzed in a meta-study, revealing growth related pathways and those associated with fatty acid metabolism and the lysosome to be related to both growth and productivity. Given the recent surge in long-non-coding RNA research and the emerging realization that these so long-ignored molecules are one of the main mechanisms of controlling changes in gene expression and transcript levels, DeVito and Smales [7] then present the long-non-coding transcriptome of CHO cells and how it changes during batch and fed-batch culture.Changes in lipidome over a fed-batch culture are presented by Ali et al., [8] which is of particular interest as fatty acid metabolism was one of the key features related to productivity in the transcriptome analyses discussed above. Significant changes in lipid composition of cells during the culture are highlighted, further stressing its importance for energy metabolism and thus growth, as well as for specific productivity due to the involvement in vesicular transport and as building blocks for the ER and

OPP Labeling Enables Total Protein Synthesis Quantification in CHO Production Cell Lines at the Single‐Cell Level

“…In order to allow for a more direct comparison, we transiently expressed a model protein, hEPO-Fc, in several cell lines. We selected the common host cell lines CHO-K1 and CHO-S; dihydrofolate reductase deficient CHO-DUKX B11, as well as CHO-K1 0mM (a derivative of CHO-K1 adapted to growth in the absence of glutamine [19] ), and the subclones CHO-K1 1D9, CHO-K1 4F10, and CHO-S 4F11, all three selected from their respective host cell line for elevated transient protein production. [20] Batch cultures of all cell lines were either mock-transfected or transfected with 10 or 20 μg of plasmid DNA coding for hEPO-Fc under control of a CMV-promoter.…”