Mitigating Clonal Variation in Recombinant Mammalian Cell Lines

• Published in: Trends in biotechnology (Regular ed.) Vol. 37; no. 9; pp. 931 - 942
• Main Authors: Lee, Jae Seong, Kildegaard, Helene Faustrup, Lewis, Nathan E., Lee, Gyun Min
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2019; Elsevier Limited
• Subjects: Biotechnology; Cell culture; Cell cycle; cell line development; Cell lines; clonal variation; Cloning; Efficiency; Engineering; Epigenetics; Gene amplification; Gene expression; Genome editing; Genomes; Heterogeneity; Integration; Mammals; Noise; Phenotypes; Post-translation; Predictive control; Primary production; Proteins; rational cell engineering; transgene integration; Variation; cell line development; clonal variation; rational cell engineering; transgene integration
• ISSN: 0167-7799; 1879-3096
• DOI: 10.1016/j.tibtech.2019.02.007

Mammalian expression platforms are primary production systems for therapeutic proteins that require complex post-translational modifications. Current processes used for developing recombinant mammalian cell lines generate clonal cell lines with high phenotypic heterogeneity, which has puzzled researchers that use mammalian cell culture systems for a long time. Advances in mammalian genome-editing technologies and systems biotechnology have shed light on clonal variation and enabled rational cell engineering in a targeted manner. We propose a new approach for a next-generation cell line development platform that can minimize clonal variation. Combined with the knowledge-based selection of ideal integration sites and engineering targets, targeted integration-based cell line development will allow tailored control of recombinant gene expression with predicted phenotypes. Recombinant mammalian cell line development is a critical step in the current manufacturing process for large-scale production of therapeutic proteins. The current process of cell line development using random transgene integration induces high phenotypic heterogeneity among recombinant clones, thus limiting predictive value, process streamlining, and cost-effectiveness in biopharmaceutical drug discovery and development. Recent advances in genome-editing technologies and systems biology approaches offer new insight into cell line development to minimize clonal variation. Targeted engineering strategies, combined with engineering target/integration site discovery based on multiomics data sets and in silico models, have the potential to streamline the process of cell line development with highly predictable gene expression among recombinant clones.