CAP-T cell expression system: a novel rapid and versatile human cell expression system for fast and high yield transient protein expression
© Wölfel et al; licensee BioMed Central Ltd. 2011
Published: 22 November 2011
CAP (CEVEC's Amniocyte Production) cells are an immortalized cell line based on primary human amniocytes. They were generated by transfection of these primary cells with a vector containing the functions E1 and pIX of adenovirus 5. CAP cells allow for competitive stable production of recombinant proteins with excellent biologic activity and therapeutic efficacy as a result of authentic human posttranslational modification. In order to gain access to the benefits of the CAP technology also for early research, target evaluation or assay development, the transient expression system CAP-T was developed. CAP-T cells are based on the original CAP cells and additionally express the large T antigen of simian virus 40 (SV40).
Table 1 summarizes the relevant data from transient transfections of CAP-T cells in different scales with plasmids coding for different proteins of interest (hAAT, erythropoietin (EPO), C1-Inhibitor and IgG). Cells were either transfected by nucleofection (1 x 107 cells) or by PEI (1.7 x 109 cells).
1 x 107
1.7 x 109
1 x 107
1 x 107
1 x 107
culture volume [ml]
culture time [days]
viability at harvest [%]
volumetric productivity [mg/L]
In summary, CAP-T cells present a highly efficient transient expression system enabling the generation of mg amounts of the protein of interest for early research and development within only two weeks from gene to product. Furthermore, CAP-T cell produced proteins showed fully human posttranslational modification pattern, which was also observed for the original human CAP cells, the CAP-T cells were derived from. The CAP technology based on CAP-T cells for transient transfection and CAP cells for stable protein production  therefore provides a unique system in which the whole process from early research to production of therapeutic proteins can be run through with the same cell type.
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