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Tasan I, Eres I, Wei C, Bryant EE, Brisan E, Hubert R. Identification of Loci with High Transgene Expression in CHO Cells. ACS Synth Biol 2025. [PMID: 40357755 DOI: 10.1021/acssynbio.4c00678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2025]
Abstract
Chinese Hamster Ovary (CHO) cells are commonly used for producing therapeutic proteins in the biopharmaceutical industry. Targeted integration (TI) of therapeutic protein-encoding transgenes into predetermined high and stably expressing genomic loci can simplify the cell line development processes for biologics production. Establishing a successful TI system requires identifying genomic loci that allow a high expression of the integrated transgenes. In this work, we demonstrated that the Thousands of Reporters Integrated in Parallel (TRIP) technology can identify such transcriptional hotspots in CHO cells. TRIP simplifies screening for transcriptional hotspots since it utilizes randomly integrated barcoded reporters and uses each barcode as a unique identifier to track the genomic location and activity of the corresponding reporter by next-generation sequencing. Transcriptional hotspots identified by TRIP resulted in up to a 9.4-fold increase in mRNA levels and a 5.6-fold increase in fed-batch titers of a test molecule compared with a medium-expressing control locus. Moreover, single copy expression from one of the identified transcriptional hotspots resulted in up to a 1.6-fold higher titer in comparison to the piggyBac-mediated stable expression of the same molecule. Reporter expression levels from TRIP loci showed positive correlations with active chromatin marks; however, the proximity to active marks was not consistently deterministic. These results suggest that TRIP is a powerful functional screening method for identifying transcriptional hotspots in CHO cells without the need for more complex epigenomic analyses.
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Affiliation(s)
- Ipek Tasan
- Amgen Research, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Ittai Eres
- Amgen Research, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Christopher Wei
- Amgen Research, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Eric Edward Bryant
- Amgen Research, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Emil Brisan
- Amgen Research, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
| | - Rene Hubert
- Amgen Research, Amgen, Inc., One Amgen Center Drive, Thousand Oaks, California 91320, United States
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Ng JPZ, Mariati M, Bi J, Chang MW, Yang Y. A Targeted Integration-Based CHO Cell Platform for Simultaneous Antibody Display and Secretion. Antibodies (Basel) 2025; 14:38. [PMID: 40407690 PMCID: PMC12101391 DOI: 10.3390/antib14020038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2025] [Revised: 04/22/2025] [Accepted: 04/24/2025] [Indexed: 05/26/2025] Open
Abstract
OBJECTIVE We developed a targeted integration-based CHO cell platform for simultaneous antibody display and secretion, enabling a streamlined transition from antibody library screening to production without requiring the re-cloning of antibody genes. METHODS The platform consists of a CHO master cell line with a single-copy landing pad, a helper vector expressing FLPe recombinase, and bi-functional targeting vectors. Recombinase-mediated cassette exchange was utilized to integrate targeting vectors into the landing pad. Bi-functional vectors were designed by incorporating a minimal furin cleavage sequence (mFCS), RRKR, and various 2A peptides between the heavy chain (HC) and a membrane anchor. RESULTS Incomplete cleavage at the mFCS and 2A sites facilitated the expression of both membrane-bound and secreted antibodies, while mutations in the 2A peptide produced a range of display-to-secretion ratios. However, a fraction of secreted antibodies retained 2A residues attached to the HC polypeptides. Further analysis demonstrated that modifying the first five amino acids of the 2A peptide significantly influenced furin cleavage efficiency, resulting in different display-to-secretion ratios for targeting vectors containing mFCS-2A variant combinations. To overcome this, we designed nine-amino-acid FCS variants that, when placed between the HC and membrane anchor, provided a range of display-to-secretion ratios and eliminated the issue of attached 2A residues in the secreted antibodies. Vectors with lower display levels proved more effective at distinguishing cells expressing high-affinity antibodies with closely matched binding affinities. The platform also demonstrated high sensitivity in isolating high-affinity antibody-expressing cells and supported robust antibody production. CONCLUSION This targeted integration-based CHO platform enables efficient, in-format screening and production of antibodies with tunable display-to-secretion profiles. It provides a powerful and scalable tool for accelerating the development of functional, manufacturable therapeutic antibodies.
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Affiliation(s)
- Jessica P. Z. Ng
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #03-01 Centros, Singapore 138668, Singapore
| | - Mariati Mariati
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #03-01 Centros, Singapore 138668, Singapore
| | - Jiawu Bi
- Institute of Molecular Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Dr, #07-01 Proteos, Singapore 138673, Singapore;
| | - Matthew Wook Chang
- Synthetic Biology Translation Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117465, Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Dr, #02-07 Centre for Life Sciences, Singapore 117456, Singapore
| | - Yuansheng Yang
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A*STAR), 20 Biopolis Way, #03-01 Centros, Singapore 138668, Singapore
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Xiao W, Jiang W, Chen Z, Huang Y, Mao J, Zheng W, Hu Y, Shi J. Advance in peptide-based drug development: delivery platforms, therapeutics and vaccines. Signal Transduct Target Ther 2025; 10:74. [PMID: 40038239 PMCID: PMC11880366 DOI: 10.1038/s41392-024-02107-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 11/01/2024] [Accepted: 12/13/2024] [Indexed: 03/06/2025] Open
Abstract
The successful approval of peptide-based drugs can be attributed to a collaborative effort across multiple disciplines. The integration of novel drug design and synthesis techniques, display library technology, delivery systems, bioengineering advancements, and artificial intelligence have significantly expedited the development of groundbreaking peptide-based drugs, effectively addressing the obstacles associated with their character, such as the rapid clearance and degradation, necessitating subcutaneous injection leading to increasing patient discomfort, and ultimately advancing translational research efforts. Peptides are presently employed in the management and diagnosis of a diverse array of medical conditions, such as diabetes mellitus, weight loss, oncology, and rare diseases, and are additionally garnering interest in facilitating targeted drug delivery platforms and the advancement of peptide-based vaccines. This paper provides an overview of the present market and clinical trial progress of peptide-based therapeutics, delivery platforms, and vaccines. It examines the key areas of research in peptide-based drug development through a literature analysis and emphasizes the structural modification principles of peptide-based drugs, as well as the recent advancements in screening, design, and delivery technologies. The accelerated advancement in the development of novel peptide-based therapeutics, including peptide-drug complexes, new peptide-based vaccines, and innovative peptide-based diagnostic reagents, has the potential to promote the era of precise customization of disease therapeutic schedule.
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Affiliation(s)
- Wenjing Xiao
- Department of Pharmacy, The General Hospital of Western Theater Command, Chengdu, 610083, China
| | - Wenjie Jiang
- Department of Pharmacy, Personalized Drug Therapy Key Laboratory of Sichuan Province, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Zheng Chen
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Yu Huang
- School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Junyi Mao
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China
| | - Wei Zheng
- Department of Integrative Medicine, Xinqiao Hospital, Army Medical University, Chongqing, 400037, China
| | - Yonghe Hu
- School of Medicine, Southwest Jiaotong University, Chengdu, 610031, China
| | - Jianyou Shi
- Department of Pharmacy, Personalized Drug Therapy Key Laboratory of Sichuan Province, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China.
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Slavny P, Hegde M, Doerner A, Parthiban K, McCafferty J, Zielonka S, Hoet R. Advancements in mammalian display technology for therapeutic antibody development and beyond: current landscape, challenges, and future prospects. Front Immunol 2024; 15:1469329. [PMID: 39381002 PMCID: PMC11459229 DOI: 10.3389/fimmu.2024.1469329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2024] [Accepted: 09/04/2024] [Indexed: 10/10/2024] Open
Abstract
The evolving development landscape of biotherapeutics and their growing complexity from simple antibodies into bi- and multi-specific molecules necessitates sophisticated discovery and engineering platforms. This review focuses on mammalian display technology as a potential solution to the pressing challenges in biotherapeutic development. We provide a comparative analysis with established methodologies, highlighting key aspects of mammalian display technology, including genetic engineering, construction of display libraries, and its pivotal role in hit selection and/or developability engineering. The review delves into the mechanisms underpinning developability-driven selection via mammalian display and their broader implications. Applications beyond antibody discovery are also explored, alongside advancements towards function-first screening technologies, precision genome engineering and AI/ML-enhanced libraries, situating them in the context of mammalian display. Overall, the review provides a comprehensive overview of the current mammalian display technology landscape, underscores the expansive potential of the technology for biotherapeutic development, addresses the critical challenges for the full realisation of this potential, and examines advances in related disciplines that might impact the future application of mammalian display technologies.
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Affiliation(s)
- Peter Slavny
- Discovery & Engineering Division, Iontas Ltd./FairJourney Biologics, Cambridge, United Kingdom
| | - Manjunath Hegde
- Technology Division, Iontas/FairJourney Biologics, Cambridge, United Kingdom
| | - Achim Doerner
- Antibody Discovery & Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | - Kothai Parthiban
- Discovery & Engineering Division, Iontas Ltd./FairJourney Biologics, Cambridge, United Kingdom
| | - John McCafferty
- Maxion Therapeutics, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Stefan Zielonka
- Antibody Discovery & Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | - Rene Hoet
- Technology Division, Iontas/FairJourney Biologics, Cambridge, United Kingdom
- Technology Division, FairJourney Biologics, Porto, Portugal
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Huhtinen O, Prince S, Lamminmäki U, Salbo R, Kulmala A. Increased stable integration efficiency in CHO cells through enhanced nuclear localization of Bxb1 serine integrase. BMC Biotechnol 2024; 24:44. [PMID: 38926833 PMCID: PMC11210126 DOI: 10.1186/s12896-024-00871-4] [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: 02/02/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Mammalian display is an appealing technology for therapeutic antibody development. Despite the advantages of mammalian display, such as full-length IgG display with mammalian glycosylation and its inherent ability to select antibodies with good biophysical properties, the restricted library size and large culture volumes remain challenges. Bxb1 serine integrase is commonly used for the stable genomic integration of antibody genes into mammalian cells, but presently lacks the efficiency required for the display of large mammalian display libraries. To increase the Bxb1 integrase-mediated stable integration efficiency, our study investigates factors that potentially affect the nuclear localization of Bxb1 integrase. METHODS In an attempt to enhance Bxb1 serine integrase-mediated integration efficiency, we fused various nuclear localization signals (NLS) to the N- and C-termini of the integrase. Concurrently, we co-expressed multiple proteins associated with nuclear transport to assess their impact on the stable integration efficiency of green fluorescent protein (GFP)-encoding DNA and an antibody display cassette into the genome of Chinese hamster ovary (CHO) cells containing a landing pad for Bxb1 integrase-mediated integration. RESULTS The nucleoplasmin NLS from Xenopus laevis, when fused to the C-terminus of Bxb1 integrase, demonstrated the highest enhancement in stable integration efficiency among the tested NLS fusions, exhibiting over a 6-fold improvement compared to Bxb1 integrase lacking an NLS fusion. Subsequent additions of extra NLS fusions to the Bxb1 integrase revealed an additional 131% enhancement in stable integration efficiency with the inclusion of two copies of C-terminal nucleoplasmin NLS fusions. Further improvement was achieved by co-expressing the Ran GTPase-activating protein (RanGAP). Finally, to validate the applicability of these findings to more complex proteins, the DNA encoding the membrane-bound clinical antibody abrilumab was stably integrated into the genome of CHO cells using Bxb1 integrase with two copies of C-terminal nucleoplasmin NLS fusions and co-expression of RanGAP. This approach demonstrated over 14-fold increase in integration efficiency compared to Bxb1 integrase lacking an NLS fusion. CONCLUSIONS This study demonstrates that optimizing the NLS sequence fusion for Bxb1 integrase significantly enhances the stable genomic integration efficiency. These findings provide a practical approach for constructing larger libraries in mammalian cells through the stable integration of genes into a genomic landing pad.
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Affiliation(s)
- Olli Huhtinen
- Protein & Antibody Engineering, Orion Corporation, Turku, Finland.
- Department of Life Technologies, University of Turku, Turku, Finland.
| | - Stuart Prince
- MediCity Research Laboratory, University of Turku, Turku, Finland
- Institute of Biomedicine, University of Turku, Turku, Finland
| | - Urpo Lamminmäki
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Rune Salbo
- Protein & Antibody Engineering, Orion Corporation, Turku, Finland
| | - Antti Kulmala
- Protein & Antibody Engineering, Orion Corporation, Turku, Finland.
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Evers A, Krah S, Demir D, Gaa R, Elter D, Schroeter C, Zielonka S, Rasche N, Dotterweich J, Knuehl C, Doerner A. Engineering hydrophobicity and manufacturability for optimized biparatopic antibody-drug conjugates targeting c-MET. MAbs 2024; 16:2302386. [PMID: 38214660 PMCID: PMC10793681 DOI: 10.1080/19420862.2024.2302386] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 01/03/2024] [Indexed: 01/13/2024] Open
Abstract
Optimal combinations of paratopes assembled into a biparatopic antibody have the capacity to mediate high-grade target cross-linking on cell membranes, leading to degradation of the target, as well as antibody and payload delivery in the case of an antibody-drug conjugate (ADC). In the work presented here, molecular docking suggested a suitable paratope combination targeting c-MET, but hydrophobic patches in essential binding regions of one moiety necessitated engineering. In addition to rational design of HCDR2 and HCDR3 mutations, site-specific spiking libraries were generated and screened in yeast and mammalian surface display approaches. Comparative analyses revealed similar positions amendable for hydrophobicity reduction, with a broad combinatorial diversity obtained from library outputs. Optimized variants showed high stability, strongly reduced hydrophobicity, retained affinities supporting the desired functionality and enhanced producibility. The resulting biparatopic anti-c-MET ADCs were comparably active on c-MET expressing tumor cell lines as REGN5093 exatecan DAR6 ADC. Structural molecular modeling of paratope combinations for preferential inter-target binding combined with protein engineering for manufacturability yielded deep insights into the capabilities of rational and library approaches. The methodologies of in silico hydrophobicity identification and sequence optimization could serve as a blueprint for rapid development of optimal biparatopic ADCs targeting further tumor-associated antigens in the future.
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Affiliation(s)
- Andreas Evers
- Antibody Discovery and Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | - Simon Krah
- Antibody Discovery and Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | - Deniz Demir
- Antibody Discovery and Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | - Ramona Gaa
- Antibody Discovery and Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | - Desislava Elter
- Antibody Discovery and Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | | | - Stefan Zielonka
- Antibody Discovery and Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
| | - Nicolas Rasche
- ADC and Targeted Therapeutics, Merck Healthcare KGaA, Darmstadt, Germany
| | | | - Christine Knuehl
- Research Unit Oncology, Merck Healthcare KGaA, Darmstadt, Germany
| | - Achim Doerner
- Antibody Discovery and Protein Engineering, Merck Healthcare KGaA, Darmstadt, Germany
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Gaa R, Mayer HM, Noack D, Kumari K, Guenther R, Tsai SP, Ji Q, Doerner A. Mammalian display to secretion switchable libraries for antibody preselection and high throughput functional screening. MAbs 2023; 15:2251190. [PMID: 37646089 PMCID: PMC10469430 DOI: 10.1080/19420862.2023.2251190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/10/2023] [Accepted: 08/20/2023] [Indexed: 09/01/2023] Open
Abstract
Recently, there has been a co-evolution of mammalian libraries and diverse microfluidic approaches for therapeutic antibody hit discovery. Mammalian libraries enable the preservation of full immune repertoires, produce hit candidates in final format and facilitate broad combinatorial bispecific antibody screening, while several available microfluidic methodologies offer opportunities for rapid high-content screens. Here, we report proof-of-concept studies exploring the potential of combining microfluidic technologies with mammalian libraries for antibody discovery. First, antibody secretion, target co-expression and integration of appropriate reporter cell lines enabled the selection of in-trans acting agonistic bispecific antibodies. Second, a functional screen for internalization was established and comparison of autocrine versus co-encapsulation setups highlighted the advantages of an autocrine one cell approach. Third, synchronization of antibody-secreting cells prior to microfluidic screens reduced assay variability. Furthermore, a display to secretion switchable system was developed and applied for pre-enrichment of antibody clones with high manufacturability in conjunction with subsequent screening for functional properties. These case studies demonstrate the system's feasibility and may serve as basis for further development of integrated workflows combining manufacturability sorting and functional screens for the identification of optimal therapeutic antibody candidates.
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Affiliation(s)
- Ramona Gaa
- NBE Technologies, Merck KGaA, Darmstadt, Germany
| | | | | | - Kavita Kumari
- Discovery Biology, Syngene International, Bangalore, India
| | | | | | - Qingyong Ji
- NBE Technologies, EMD Serono, Billerica, MA, USA
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