Proteins improving recombinant antibody production in mammalian cells

Abstract

Mammalian cells have been successfully used for the industrial manufacture of antibodies due to their ability to synthesize antibodies correctly. Nascent polypeptides must be subjected to protein folding and assembly in the ER and the Golgi to be secreted as mature proteins. If these reactions do not proceed appropriately, unfolded or misfolded proteins are degraded by the ER-associated degradation (ERAD) pathway. The accumulation of unfolded proteins or intracellular antibody crystals accompanied by this failure triggers the unfolded protein response (UPR), which can considerably attenuate the levels of translation, folding, assembly, and secretion, resulting in reduction of antibody productivity. Accumulating studies by omics-based analysis of recombinant mammalian cells suggest that not only protein secretion processes including protein folding and assembly but also translation are likely to be the rate-limiting factors for increasing antibody production. Here, this review describes the mechanism of antibody folding and assembly and recent advantages which could improve recombinant antibody production in mammalian cells by utilizing proteins such as ER chaperones or UPR-related proteins.

A long non-coding SINEUP RNA boosts semi-stable production of fully human monoclonal antibodies in HEK293E cells

“…Our SINEUP system adds to those already established for optimization of mAb production. 11-13 The combination of SINEUP technology with existing and upcoming technologies will be evaluated in the future, to verify whether optimal mAb production can be reached, in terms of even more pronounced yields and unaltered PTMs.…”

“…Since apoptosis is the main cause of cell death during cultivation, different anti-apoptotic engineering approaches have been exploited to select apoptosis-resistant cells by, for instance, overexpression of anti-apoptotic Bcl-2 family proteins, human telomerase reverse transcriptase (hTert), or acting on cell cycle through p53, cyclin E, E2F-1, p21, p27 and p18 6 11 , 12 Other authors have focused on enhancing protein folding or reducing unfolded protein response (UPR), typical conditions of highly producing cell lines 13 . Thanks to these engineering approaches, to date, very good productivity in HEK293 cells, up to about 300 mg/L has been reported 12 …”

Improving the secretory capacity of Chinese hamster ovary cells by ectopic expression of effector genes: Lessons learned and future directions

“…In contrast to PDI, the effect of many effector genes on volumetric productivity or q p has only been reported once (Hussain et al, 2014;Nishimiya, 2013). Notwithstanding product specificity, it is likely that a considerable number of these effects are conditional -for example, specific to the monoclonal cell line or the expression platform being used.…”

“…In many cases, such engineering efforts have led to positive effects on q p on a variety of r-proteins (see recent reviews (Fischer et al, 2015;Hussain et al, 2014;Nishimiya, 2013)). This multitude of studies showing positive effects clearly underpins the potential of modulating the expression of effector genes.…”

Network reconstruction of the mouse secretory pathway applied on CHO cell transcriptome data

“…In Fig. 5 it is noticed that several of the known targets for optimised protein production in CHO cells (XBP1, ATF4, BIP, ERP72/PDI4, CNX [27, 32] have high negative correlation to growth, but interestingly with little correlation to IgG production. Possibly, many of these are a part of a stress response under normal regulation, and therefore correlate with low growth rates.…”