Enhancing CHO cell recombinant protein production using a perfusion-directed host evolution approach

Clonally derived cell lines generated from Chinese hamster ovary (CHO) cells encounter numerous stressors when cultured in high-intensity perfusion bioreactors leading to poor process performance. To circumvent this, the ability of CHO cells to adapt to different culture environments was exploited. Here host cells were selected in the presence of physical and chemical stressors associated with a perfusion environment by culturing at a high cell density in a perfusion bioreactor for 30 days. Following recovery and expansion, the performance of the resulting perfusion-evolved host was evaluated using stable transfectant pools and clones expressing biotherapeutics of different formats. Cell lines generated from the perfusion host outperformed the parental host at several fundamental stages of the clone selection process. Perfusion host-derived pools showed elevations in productivity, cell-specific productivity, end-of-run viability, and reduced lactate production in fed-batch culture. Use of the perfusion host for cell line generation resulted in an increased frequency of high-producing clones. Moreover, the perfusion host-derived clones demonstrated 30% higher productivity and improved mannose profile in the perfusion environment compared to the clones from the parental host. Furthermore, a comparative proteomic analysis between the two host types revealed unique regulatory networks that allowed us to gain insights into the underlying molecular processes influencing production performance. Taken together, the results suggest that the perfusion host may not only increase the efficiency of the cell line development process but may also serve as an efficient tool for improvement in production capability in the perfusion platform.