2024 AIChE Annual Meeting
(174be) Transporter Engineering for Improved CHO Cell Culture
Author
Chinese Hamster Ovary (CHO) cells are an industrial standard for the manufacturing of some of the most significant biopharmaceutical therapies available. In pursuit of high protein yield, extensive research has been dedicated to culture conditions, media optimization, and metabolic tuning. Yet, membrane transport has been relatively underexplored due to the difficulty of expressing transporters and limited knowledge of their function. Recent work in the field has defined transporter expression and characterized patterns of transporter expression in CHO cell culture. Here, we leverage that information to express transporters that tune the glutamine/glutamate uptake in flask cultures. Specifically, we find that CHO cells expressing small neutral amino acid solute carriers consistently achieve higher viable cell density (VCD) and increased glutamine/glutamate uptake than equivalently burdened control cultures. Notably, this is only true for intermediate expression, as cultures expressing the transporter with the standard CMV promoter appear to be overburdened. Then, we show that using a standard library of different promoters in a modular cloning standard can quickly identify the ideal expression level for these proteins. Due to the diversity of transporters, and the modular nature of our approach, our initial data has provided a strong foundation for increased emphasis on transporter engineering in cell culture optimization. Thus, these initial results support the idea that transporter engineering can add a new level of precision control over cell culture performance, in addition to traditional media optimization and metabolic engineering. This new dimension to cell line development could significantly impact growth and yield of recombinant protein producing cell lines.