Engineering of Chinese Hamster Ovary Cells With NDPK-A to Enhance DNA Nuclear Delivery Combined With EBNA1 Plasmid Maintenance Gives Improved Exogenous Transient Reporter, mAb and SARS-CoV-2 Spike Protein Expression

Transient gene expression (TGE) in mammalian cells is a method of rapidly generating recombinant protein material for initial characterisation studies that does not require time-consuming processes associated with stable cell line construction. High TGE yields are heavily dependent on efficient delivery plasmid DNA across both the plasma and nuclear membranes. Here, we harness nucleoside diphosphate kinase (NDPK-A) contains localisation signal (NLS) to enhance into nucleus CHO cells. We show co-expression NDPK-A during transient results improved transfection efficiency cells, presumably due enhanced transportation via pore complex. Furthermore, introduction Epstein Barr Nuclear Antigen-1 (EBNA-1), capable inducing extrachromosomal maintenance, when coupled complementary oriP elements plasmid, was utilised reduce effect dilution. Whilst there attenuated growth upon EBNA-1 system import mediated technologies were employed together this resulted superior those generated using either approach independently, including expressing complex SARS-CoV-2 spike (S) glycoprotein.