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Howe G, Wasmuth M, Emanuelle P, Massaro G, Rahim AA, Ali S, Rivera M, Ward J, Keshavarz-Moore E, Mason C, Nesbeth DN. Engineering an Autonucleolytic Mammalian Suspension Host Cell Line to Reduce DNA Impurity Levels in Serum-Free Lentiviral Process Streams. ACS Synth Biol 2024; 13:466-473. [PMID: 38266181 PMCID: PMC10877604 DOI: 10.1021/acssynbio.3c00682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/26/2024]
Abstract
We engineered HEK293T cells with a transgene encoding tetracycline-inducible expression of a Staphylococcus aureus nuclease incorporating a translocation signal. We adapted the unmodified and nuclease-engineered cell lines to grow in suspension in serum-free media, generating the HEK293TS and NuPro-2S cell lines, respectively. Transient transfection yielded 1.19 × 106 lentiviral transducing units per milliliter (TU/mL) from NuPro-2S cells and 1.45 × 106 TU/mL from HEK293TS cells. DNA ladder disappearance revealed medium-resident nuclease activity arising from NuPro-2S cells in a tetracycline-inducible manner. DNA impurity levels in lentiviral material arising from NuPro-2S and HEK293TS cells were undetectable by SYBR Safe agarose gel staining. Direct measurement by PicoGreen reagent revealed DNA to be present at 636 ng/mL in lentiviral material from HEK293TS cells, an impurity level reduced by 89% to 70 ng/mL in lentiviral material from NuPro-2S cells. This reduction was comparable to the 23 ng/mL achieved by treating HEK293TS-derived lentiviral material with 50 units/mL Benzonase.
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Affiliation(s)
- Geoffrey Howe
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - Matthew Wasmuth
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - Pamela Emanuelle
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - Giulia Massaro
- UCL
School of Pharmacy, University College London, London WC1N 1AX, U.K.
| | - Ahad A. Rahim
- UCL
School of Pharmacy, University College London, London WC1N 1AX, U.K.
| | - Sadfer Ali
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - Milena Rivera
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - John Ward
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - Eli Keshavarz-Moore
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - Chris Mason
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
| | - Darren N. Nesbeth
- Department
of Biochemical Engineering, University College
London, Bernard Katz
Building, London WC1E 6BT, United Kingdom
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