1. Genomic features of recombinant CHO clones arising from transposon-based and randomized integration.
- Author
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Huhn SC, Chang M, Jiang B, Tang X, Betenbaugh M, and Du Z
- Subjects
- Cricetinae, Animals, Cricetulus, CHO Cells, Clone Cells, Genomics, DNA Transposable Elements genetics, Transposases genetics, Transposases metabolism
- Abstract
The use of transposase in cell line development (CLD) programs has experienced increased popularity over the past decade. However, few studies have described the mechanism of action and the genomic and phenotypic characteristics of clones derived from transposase. Additionally, how these traits impact long-term bioproduction is unknown. Here, we use chromosome painting, deep sequencing, and ddPCR to characterize the unique fingerprints associated with transposase-derived clones. Transposase reduces the cellular pool of transient vector as early as three days post transfection following transfection and expedites stable pool establishment by up to two weeks. Furthermore, recombinant DNA expression is significantly improved up to ∼3 fold along with a greater balance of antibody heavy and light chain transcripts, resulting in higher titers in transposase generated pools. Transposase derived pools contained an often innumerable number of integration sites, representing a vast increase in integration site diversity over randomly generated pools, which were bottlenecked at 1-3 integration sites per pool. These transposase mediated integrations typically occurred in clean singlets, free of genomic scars such as deletions, inversions, and other modifications associated with legacy transfection methods which exhibited higher copy numbers per integration site. Relative declines in gene expression occur with copy number increase in the randomly generated, but not the transposase derived clones. Furthermore, transposase-derived clones were more likely to exhibit enhanced a long term stability profile, including product quality attributes such as mannose-5. This improved stability may result from circumventing mechanisms associated with the silencing of tandem repeats. Thus, transposase-mediated approaches can provide multifaceted molecular and phenotypic advantages in cell line development when compared to legacy random-integration methods., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: S. Huhn, B. Jiang, M. Chang, X. Tang, Z. Du are employees of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA and potentially own stock and/or hold stock options in Merck & Co., Inc., Kenilworth, NJ, USA. Merck & Co., Inc provided support in the form of salaries for all authors but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the “author contributions” section., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
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