1
|
Wagner N, Musiychuk K, Shoji Y, Tottey S, Streatfield SJ, Fischer R, Yusibov V. Basic leucine zipper transcription activators - tools to improve production and quality of human erythropoietin in Nicotiana benthamiana. Biotechnol J 2024; 19:e2300715. [PMID: 38797727 DOI: 10.1002/biot.202300715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 04/02/2024] [Accepted: 04/25/2024] [Indexed: 05/29/2024]
Abstract
Human erythropoietin (hEPO) is one of the most in-demand biopharmaceuticals, however, its production is challenging. When produced in a plant expression system, hEPO results in extensive plant tissue damage and low expression. It is demonstrated that the modulation of the plant protein synthesis machinery enhances hEPO production. Co-expression of basic leucine zipper transcription factors with hEPO prevents plant tissue damage, boosts expression, and increases hEPO solubility. bZIP28 co-expression up-regulates genes associated with the unfolded protein response, indicating that the plant tissue damage caused by hEPO expression is due to the native protein folding machinery being overwhelmed and that this can be overcome by co-expressing bZIP28.
Collapse
Affiliation(s)
- Nazgul Wagner
- Biotechnology Division, Fraunhofer USA Inc., Center Mid-Atlantic, Newark, Delaware, USA
- Institute for Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Konstantin Musiychuk
- Biotechnology Division, Fraunhofer USA Inc., Center Mid-Atlantic, Newark, Delaware, USA
| | - Yoko Shoji
- Biotechnology Division, Fraunhofer USA Inc., Center Mid-Atlantic, Newark, Delaware, USA
| | - Stephen Tottey
- Biotechnology Division, Fraunhofer USA Inc., Center Mid-Atlantic, Newark, Delaware, USA
| | - Stephen J Streatfield
- Biotechnology Division, Fraunhofer USA Inc., Center Mid-Atlantic, Newark, Delaware, USA
| | - Rainer Fischer
- Institute for Molecular Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Vidadi Yusibov
- Biotechnology Division, Fraunhofer USA Inc., Center Mid-Atlantic, Newark, Delaware, USA
| |
Collapse
|
2
|
Strasser R. Plant glycoengineering for designing next-generation vaccines and therapeutic proteins. Biotechnol Adv 2023; 67:108197. [PMID: 37315875 DOI: 10.1016/j.biotechadv.2023.108197] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 06/16/2023]
Abstract
Protein glycosylation has a huge impact on biological processes in all domains of life. The type of glycan present on a recombinant glycoprotein depends on protein intrinsic features and the glycosylation repertoire of the cell type used for expression. Glycoengineering approaches are used to eliminate unwanted glycan modifications and to facilitate the coordinated expression of glycosylation enzymes or whole metabolic pathways to furnish glycans with distinct modifications. The formation of tailored glycans enables structure-function studies and optimization of therapeutic proteins used in different applications. While recombinant proteins or proteins from natural sources can be in vitro glycoengineered using glycosyltransferases or chemoenzymatic synthesis, many approaches use genetic engineering involving the elimination of endogenous genes and introduction of heterologous genes to cell-based production systems. Plant glycoengineering enables the in planta production of recombinant glycoproteins with human or animal-type glycans that resemble natural glycosylation or contain novel glycan structures. This review summarizes key achievements in glycoengineering of plants and highlights current developments aiming to make plants more suitable for the production of a diverse range of recombinant glycoproteins for innovative therapies.
Collapse
Affiliation(s)
- Richard Strasser
- Institute of Plant Biotechnology and Cell Biology, Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria.
| |
Collapse
|
3
|
Buyel JF. Product safety aspects of plant molecular farming. Front Bioeng Biotechnol 2023; 11:1238917. [PMID: 37614627 PMCID: PMC10442644 DOI: 10.3389/fbioe.2023.1238917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/31/2023] [Indexed: 08/25/2023] Open
Abstract
Plant molecular farming (PMF) has been promoted since the 1990s as a rapid, cost-effective and (most of all) safe alternative to the cultivation of bacteria or animal cells for the production of biopharmaceutical proteins. Numerous plant species have been investigated for the production of a broad range of protein-based drug candidates. The inherent safety of these products is frequently highlighted as an advantage of PMF because plant viruses do not replicate in humans and vice versa. However, a more nuanced analysis of this principle is required when considering other pathogens because toxic compounds pose a risk even in the absence of replication. Similarly, it is necessary to assess the risks associated with the host system (e.g., the presence of toxic secondary metabolites) and the production approach (e.g., transient expression based on bacterial infiltration substantially increases the endotoxin load). This review considers the most relevant host systems in terms of their toxicity profile, including the presence of secondary metabolites, and the risks arising from the persistence of these substances after downstream processing and product purification. Similarly, we discuss a range of plant pathogens and disease vectors that can influence product safety, for example, due to the release of toxins. The ability of downstream unit operations to remove contaminants and process-related toxic impurities such as endotoxins is also addressed. This overview of plant-based production, focusing on product safety aspects, provides recommendations that will allow stakeholders to choose the most appropriate strategies for process development.
Collapse
Affiliation(s)
- J. F. Buyel
- Department of Biotechnology (DBT), Institute of Bioprocess Science and Engineering (IBSE), University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| |
Collapse
|
4
|
Eidenberger L, Kogelmann B, Steinkellner H. Plant-based biopharmaceutical engineering. NATURE REVIEWS BIOENGINEERING 2023; 1:426-439. [PMID: 37317690 PMCID: PMC10030082 DOI: 10.1038/s44222-023-00044-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/13/2023] [Indexed: 03/24/2023]
Abstract
Plants can be engineered to recombinantly produce high-quality proteins such as therapeutic proteins and vaccines, also known as molecular farming. Molecular farming can be established in various settings with minimal cold-chain requirements and could thus ensure rapid and global-scale deployment of biopharmaceuticals, promoting equitable access to pharmaceuticals. State of the art plant-based engineering relies on rationally assembled genetic circuits, engineered to enable the high-throughput and rapid expression of multimeric proteins with complex post-translational modifications. In this Review, we discuss the design of expression hosts and vectors, including Nicotiana benthamiana, viral elements and transient expression vectors, for the production of biopharmaceuticals in plants. We examine engineering of post-translational modifications and highlight the plant-based expression of monoclonal antibodies and nanoparticles, such as virus-like particles and protein bodies. Techno-economic analyses suggest a cost advantage of molecular farming compared with mammalian cell-based protein production systems. However, regulatory challenges remain to be addressed to enable the widespread translation of plant-based biopharmaceuticals.
Collapse
Affiliation(s)
- Lukas Eidenberger
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Benjamin Kogelmann
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
- acib — Austrian Centre of Industrial Biotechnology, Vienna, Austria
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| |
Collapse
|
5
|
Assessment of transient expression strategies to sialylate recombinant proteins in N. benthamiana. J Biotechnol 2023; 365:48-53. [PMID: 36805356 DOI: 10.1016/j.jbiotec.2023.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/08/2023] [Accepted: 02/12/2023] [Indexed: 02/17/2023]
Abstract
There is a demand for increasing the current manufacturing capacities for recombinant protein-based drugs. Novel expression systems such as plants are being explored as faster, more flexible, and possibly cheaper platforms. Many of these therapeutic proteins are glycosylated and require terminal sialylation to attain full biological activity. In planta protein sialylation has been achieved by the introduction of an entire mammalian biosynthetic pathway in Nicotiana benthamiana, comprising the coordinated expression of the genes for (i) biosynthesis, (ii) activation, (iii) transport, and (iv) transfer of Neu5Ac to terminal galactose. Here we address technical issues that can compromise the efficacy of protein sialylation and how they can be overcome. We used the same reporter protein to compared three strategies to transiently deliver the sialylation pathway-genes evaluating efficacy, heterogeneity and batch-to-batch consistency. In addition, we assess the ability of the single-step method to sialylated additional recombinant proteins with different complexity and number of glycosylation sites. Finally, we show that efficient protein sialylation can be up-scaled for large-scale production of sialylated proteins in plants.
Collapse
|
6
|
Improving Protein Quantity and Quality—The Next Level of Plant Molecular Farming. Int J Mol Sci 2022; 23:ijms23031326. [PMID: 35163249 PMCID: PMC8836236 DOI: 10.3390/ijms23031326] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/21/2022] [Accepted: 01/22/2022] [Indexed: 12/15/2022] Open
Abstract
Plants offer several unique advantages in the production of recombinant pharmaceuticals for humans and animals. Although numerous recombinant proteins have been expressed in plants, only a small fraction have been successfully put into use. The hugely distinct expression systems between plant and animal cells frequently cause insufficient yield of the recombinant proteins with poor or undesired activity. To overcome the issues that greatly constrain the development of plant-produced pharmaceuticals, great efforts have been made to improve expression systems and develop alternative strategies to increase both the quantity and quality of the recombinant proteins. Recent technological revolutions, such as targeted genome editing, deconstructed vectors, virus-like particles, and humanized glycosylation, have led to great advances in plant molecular farming to meet the industrial manufacturing and clinical application standards. In this review, we discuss the technological advances made in various plant expression platforms, with special focus on the upstream designs and milestone achievements in improving the yield and glycosylation of the plant-produced pharmaceutical proteins.
Collapse
|
7
|
Huang Y, Harris BS, Minami SA, Jung S, Shah PS, Nandi S, McDonald KA, Faller R. SARS-CoV-2 spike binding to ACE2 is stronger and longer ranged due to glycan interaction. Biophys J 2021; 121:79-90. [PMID: 34883069 PMCID: PMC8648368 DOI: 10.1016/j.bpj.2021.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/08/2021] [Accepted: 12/02/2021] [Indexed: 01/01/2023] Open
Abstract
Highly detailed steered molecular dynamics simulations are performed on differently glycosylated receptor binding domains of the severe acute respiratory syndrome coronavirus-2 spike protein. The binding strength and the binding range increase with glycosylation. The interaction energy rises very quickly when pulling the proteins apart and only slowly drops at larger distances. We see a catch-slip-type behavior whereby interactions during pulling break and are taken over by new interactions forming. The dominant interaction mode is hydrogen bonds, but Lennard-Jones and electrostatic interactions are relevant as well.
Collapse
Affiliation(s)
- Yihan Huang
- Department of Materials Science, UC Davis, Davis, California
| | | | - Shiaki A Minami
- Department of Chemical Engineering, UC Davis, Davis, California
| | - Seongwon Jung
- Department of Chemical Engineering, UC Davis, Davis, California
| | - Priya S Shah
- Department of Chemical Engineering, UC Davis, Davis, California; Department of Microbiology and Molecular Genetics, UC Davis, Davis, California
| | - Somen Nandi
- Department of Chemical Engineering, UC Davis, Davis, California; Global HealthShare Initiative, UC Davis, Davis, California
| | - Karen A McDonald
- Department of Chemical Engineering, UC Davis, Davis, California; Global HealthShare Initiative, UC Davis, Davis, California
| | - Roland Faller
- Department of Chemical Engineering, UC Davis, Davis, California.
| |
Collapse
|
8
|
Izadi S, Jalali Javaran M, Rashidi Monfared S, Castilho A. Reteplase Fc-fusions produced in N. benthamiana are able to dissolve blood clots ex vivo. PLoS One 2021; 16:e0260796. [PMID: 34847186 PMCID: PMC8631678 DOI: 10.1371/journal.pone.0260796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/16/2021] [Indexed: 11/19/2022] Open
Abstract
Thrombolytic and fibrinolytic therapies are effective treatments to dissolve blood clots in stroke therapy. Thrombolytic drugs activate plasminogen to its cleaved form plasmin, a proteolytic enzyme that breaks the crosslinks between fibrin molecules. The FDA-approved human tissue plasminogen activator Reteplase (rPA) is a non-glycosylated protein produced in E. coli. rPA is a deletion mutant of the wild-type Alteplase that benefits from an extended plasma half-life, reduced fibrin specificity and the ability to better penetrate into blood clots. Different methods have been proposed to improve the production of rPA. Here we show for the first time the transient expression in Nicotiana benthamiana of rPA fused to the immunoglobulin fragment crystallizable (Fc) domain on an IgG1, a strategy commonly used to improve the stability of therapeutic proteins. Despite our success on the expression and purification of dimeric rPA-Fc fusions, protein instability results in high amounts of Fc-derived degradation products. We hypothesize that the "Y"- shape of dimeric Fc fusions cause steric hindrance between protein domains and leads to physical instability. Indeed, mutations of critical residues in the Fc dimerization interface allowed the expression of fully stable rPA monomeric Fc-fusions. The ability of rPA-Fc to convert plasminogen into plasmin was demonstrated by plasminogen zymography and clot lysis assay shows that rPA-Fc is able to dissolve blood clots ex vivo. Finally, we addressed concerns with the plant-specific glycosylation by modulating rPA-Fc glycosylation towards serum-like structures including α2,6-sialylated and α1,6-core fucosylated N-glycans completely devoid of plant core fucose and xylose residues.
Collapse
Affiliation(s)
- Shiva Izadi
- Department of Applied Genetics and Cell Biology, Natural Resources and Life Sciences, Vienna, Austria
- Faculty of Agriculture, Department of Plant Genetics and Breeding, Tarbiat Modares University, Tehran, Iran
| | - Mokhtar Jalali Javaran
- Faculty of Agriculture, Department of Agricultural Biotechnology, Tarbiat Modares University, Tehran, Iran
| | - Sajad Rashidi Monfared
- Faculty of Agriculture, Department of Agricultural Biotechnology, Tarbiat Modares University, Tehran, Iran
| | - Alexandra Castilho
- Department of Applied Genetics and Cell Biology, Natural Resources and Life Sciences, Vienna, Austria
| |
Collapse
|
9
|
Schwestka J, König-Beihammer J, Shin YJ, Vavra U, Kienzl NF, Grünwald-Gruber C, Maresch D, Klausberger M, Laurent E, Stadler M, Manhart G, Huber J, Hofner M, Vierlinger K, Weinhäusel A, Swoboda I, Binder CJ, Gerner W, Grebien F, Altmann F, Mach L, Stöger E, Strasser R. Impact of Specific N-Glycan Modifications on the Use of Plant-Produced SARS-CoV-2 Antigens in Serological Assays. FRONTIERS IN PLANT SCIENCE 2021; 12:747500. [PMID: 34646292 PMCID: PMC8503525 DOI: 10.3389/fpls.2021.747500] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 09/08/2021] [Indexed: 05/04/2023]
Abstract
The receptor binding domain (RBD) of the SARS-CoV-2 spike protein plays a key role in the virus-host cell interaction, and viral infection. The RBD is a major target for neutralizing antibodies, whilst recombinant RBD is commonly used as an antigen in serological assays. Such assays are essential tools to gain control over the pandemic and detect the extent and durability of an immune response in infected or vaccinated populations. Transient expression in plants can contribute to the fast production of viral antigens, which are required by industry in high amounts. Whilst plant-produced RBDs are glycosylated, N-glycan modifications in plants differ from humans. This can give rise to the formation of carbohydrate epitopes that can be recognized by anti-carbohydrate antibodies present in human sera. For the performance of serological tests using plant-produced recombinant viral antigens, such cross-reactive carbohydrate determinants (CCDs) could result in false positives. Here, we transiently expressed an RBD variant in wild-type and glycoengineered Nicotiana benthamiana leaves and characterized the impact of different plant-specific N-glycans on RBD reactivity in serological assays. While the overall performance of the different RBD glycoforms was comparable to each other and to a human cell line produced RBD, there was a higher tendency toward false positive results with sera containing allergy-related CCD-antibodies when an RBD carrying β1,2-xylose and core α1,3-fucose was used. These rare events could be further minimized by pre-incubating sera from allergic individuals with a CCD-inhibitor. Thereby, false positive signals obtained from anti-CCD antibodies, could be reduced by 90%, on average.
Collapse
Affiliation(s)
- Jennifer Schwestka
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Julia König-Beihammer
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Yun-Ji Shin
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Ulrike Vavra
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Nikolaus F. Kienzl
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Clemens Grünwald-Gruber
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Daniel Maresch
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Miriam Klausberger
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Elisabeth Laurent
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
- Core Facility Biomolecular & Cellular Analysis, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Maria Stadler
- Institute of Immunology, University of Veterinary Medicine, Vienna, Austria
| | - Gabriele Manhart
- Institute for Medical Biochemistry, University of Veterinary Medicine, Vienna, Austria
| | - Jasmin Huber
- Competence Unit Molecular Diagnostics, Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Vienna, Austria
| | - Manuela Hofner
- Competence Unit Molecular Diagnostics, Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Vienna, Austria
| | - Klemens Vierlinger
- Competence Unit Molecular Diagnostics, Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Vienna, Austria
| | - Andreas Weinhäusel
- Competence Unit Molecular Diagnostics, Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Vienna, Austria
| | - Ines Swoboda
- Biotechnology Section, FH Campus Wien, University of Applied Sciences, Vienna, Austria
| | - Christoph J. Binder
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Wilhelm Gerner
- Institute of Immunology, University of Veterinary Medicine, Vienna, Austria
| | - Florian Grebien
- Institute for Medical Biochemistry, University of Veterinary Medicine, Vienna, Austria
| | - Friedrich Altmann
- Department of Chemistry, Institute of Biochemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Lukas Mach
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Eva Stöger
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| |
Collapse
|
10
|
Castilho A, Schwestka J, Kienzl NF, Vavra U, Grünwald‐Gruber C, Izadi S, Hiremath C, Niederhöfer J, Laurent E, Monteil V, Mirazimi A, Wirnsberger G, Stadlmann J, Stöger E, Mach L, Strasser R. Generation of enzymatically competent SARS-CoV-2 decoy receptor ACE2-Fc in glycoengineered Nicotiana benthamiana. Biotechnol J 2021; 16:e2000566. [PMID: 33481336 PMCID: PMC7995010 DOI: 10.1002/biot.202000566] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 01/05/2023]
Abstract
Human angiotensin-converting enzyme 2 (ACE2) is the primary host cell receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binding and cell entry. Administration of high concentrations of soluble ACE2 can be utilized as a decoy to block the interaction of the virus with cellular ACE2 receptors and potentially be used as a strategy for treatment or prevention of coronavirus disease 2019. Human ACE2 is heavily glycosylated and its glycans impact on binding to the SARS-CoV-2 spike protein and virus infectivity. Here, we describe the production of a recombinant soluble ACE2-fragment crystallizable (Fc) variant in glycoengineered Nicotiana benthamiana. Our data reveal that the produced dimeric ACE2-Fc variant is glycosylated with mainly complex human-type N-glycans and functional with regard to enzyme activity, affinity to the SARS-CoV-2 receptor-binding domain, and wild-type virus neutralization.
Collapse
Affiliation(s)
- Alexandra Castilho
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Jennifer Schwestka
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Nikolaus F. Kienzl
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Ulrike Vavra
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Clemens Grünwald‐Gruber
- Department of ChemistryInstitute of BiochemistryUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Shiva Izadi
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
- Department of BiotechnologyFaculty of AgricultureTarbiat Modares UniversityTehranIran
| | - Chaitra Hiremath
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | | | - Elisabeth Laurent
- Department of Biotechnology and Core Facility Biomolecular & Cellular AnalysisUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Vanessa Monteil
- Department of Laboratory MedicineUnit of Clinical MicrobiologyKarolinska Institute and Karolinska University HospitalStockholmSweden
| | - Ali Mirazimi
- Department of Laboratory MedicineUnit of Clinical MicrobiologyKarolinska Institute and Karolinska University HospitalStockholmSweden
| | | | - Johannes Stadlmann
- Department of ChemistryInstitute of BiochemistryUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Eva Stöger
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Lukas Mach
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| | - Richard Strasser
- Department of Applied Genetics and Cell BiologyInstitute of Plant Biotechnology and Cell BiologyUniversity of Natural Resources and Life Sciences ViennaViennaAustria
| |
Collapse
|
11
|
Buyel JF, Stöger E, Bortesi L. Targeted genome editing of plants and plant cells for biomanufacturing. Transgenic Res 2021; 30:401-426. [PMID: 33646510 PMCID: PMC8316201 DOI: 10.1007/s11248-021-00236-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 02/03/2021] [Indexed: 02/07/2023]
Abstract
Plants have provided humans with useful products since antiquity, but in the last 30 years they have also been developed as production platforms for small molecules and recombinant proteins. This initially niche area has blossomed with the growth of the global bioeconomy, and now includes chemical building blocks, polymers and renewable energy. All these applications can be described as “plant molecular farming” (PMF). Despite its potential to increase the sustainability of biologics manufacturing, PMF has yet to be embraced broadly by industry. This reflects a combination of regulatory uncertainty, limited information on process cost structures, and the absence of trained staff and suitable manufacturing capacity. However, the limited adaptation of plants and plant cells to the requirements of industry-scale manufacturing is an equally important hurdle. For example, the targeted genetic manipulation of yeast has been common practice since the 1980s, whereas reliable site-directed mutagenesis in most plants has only become available with the advent of CRISPR/Cas9 and similar genome editing technologies since around 2010. Here we summarize the applications of new genetic engineering technologies to improve plants as biomanufacturing platforms. We start by identifying current bottlenecks in manufacturing, then illustrate the progress that has already been made and discuss the potential for improvement at the molecular, cellular and organism levels. We discuss the effects of metabolic optimization, adaptation of the endomembrane system, modified glycosylation profiles, programmable growth and senescence, protease inactivation, and the expression of enzymes that promote biodegradation. We outline strategies to achieve these modifications by targeted gene modification, considering case-by-case examples of individual improvements and the combined modifications needed to generate a new general-purpose “chassis” for PMF.
Collapse
Affiliation(s)
- J F Buyel
- Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Forckenbeckstrasse 6, 52074, Aachen, Germany. .,Institute for Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
| | - E Stöger
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - L Bortesi
- Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Brightlands Chemelot Campus, Urmonderbaan 22, 6167 RD, Geleen, The Netherlands
| |
Collapse
|
12
|
Beihammer G, Maresch D, Altmann F, Van Damme EJM, Strasser R. Lewis A Glycans Are Present on Proteins Involved in Cell Wall Biosynthesis and Appear Evolutionarily Conserved Among Natural Arabidopsis thaliana Accessions. FRONTIERS IN PLANT SCIENCE 2021; 12:630891. [PMID: 33777069 PMCID: PMC7991798 DOI: 10.3389/fpls.2021.630891] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/18/2021] [Indexed: 05/02/2023]
Abstract
N-glycosylation is a highly abundant protein modification present in all domains of life. Terminal sugar residues on complex-type N-glycans mediate various crucial biological processes in mammals such as cell-cell recognition or protein-ligand interactions. In plants, the Lewis A trisaccharide constitutes the only known outer-chain elongation of complex N-glycans. Lewis A containing complex N-glycans appear evolutionary conserved, having been identified in all plant species analyzed so far. Despite their ubiquitous occurrence, the biological function of this complex N-glycan modification is currently unknown. Here, we report the identification of Lewis A bearing glycoproteins from three different plant species: Arabidopsis thaliana, Nicotiana benthamiana, and Oryza sativa. Affinity purification via the JIM84 antibody, directed against Lewis A structures on complex plant N-glycans, was used to enrich Lewis A bearing glycoproteins, which were subsequently identified via nano-LC-MS. Selected identified proteins were recombinantly expressed and the presence of Lewis A confirmed via immunoblotting and site-specific N-glycan analysis. While the proteins identified in O. sativa are associated with diverse functions, proteins from A. thaliana and N. benthamiana are mainly involved in cell wall biosynthesis. However, a Lewis A-deficient mutant line of A. thaliana showed no change in abundance of cell wall constituents such as cellulose or lignin. Furthermore, we investigated the presence of Lewis A structures in selected accessions from the 1001 genome database containing amino acid variations in the enzymes required for Lewis A biosynthesis. Besides one relict line showing no detectable levels of Lewis A, the modification was present in all other tested accessions. The data provided here comprises the so far first attempt at identifying Lewis A bearing glycoproteins across different species and will help to shed more light on the role of Lewis A structures in plants.
Collapse
Affiliation(s)
- Gernot Beihammer
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Daniel Maresch
- Division of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Friedrich Altmann
- Division of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Els J. M. Van Damme
- Laboratory of Biochemistry and Glycobiology, Department of Biotechnology, Ghent University, Ghent, Belgium
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, Institute of Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
- *Correspondence: Richard Strasser
| |
Collapse
|
13
|
Gattinger P, Izadi S, Grünwald-Gruber C, Kallolimath S, Castilho A. The Instability of Dimeric Fc-Fusions Expressed in Plants Can Be Solved by Monomeric Fc Technology. FRONTIERS IN PLANT SCIENCE 2021; 12:671728. [PMID: 34305971 PMCID: PMC8299721 DOI: 10.3389/fpls.2021.671728] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 06/18/2021] [Indexed: 05/18/2023]
Abstract
The potential therapeutic value of many proteins is ultimately limited by their rapid in vivo clearance. One strategy to limit clearance by metabolism and excretion, and improving the stability of therapeutic proteins, is their fusion to the immunoglobulin fragment crystallizable region (Fc). The Fc region plays multiple roles in (i) dimerization for the formation of "Y"-shaped structure of Ig, (ii) Fc-mediated effector functions, (iii) extension of serum half-life, and (iv) a cost-effective purification tag. Plants and in particular Nicotiana benthamiana have proven to be suitable expression platforms for several recombinant therapeutic proteins. Despite the enormous success of their use for the production of full-length monoclonal antibodies, the expression of Fc-fused therapeutic proteins in plants has shown limitations. Many Fc-fusion proteins expressed in plants show different degrees of instability resulting in high amounts of Fc-derived degradation products. To address this issue, we used erythropoietin (EPO) as a reporter protein and evaluated the efforts to enhance the expression of full-length EPO-Fc targeted to the apoplast of N. benthamiana. Our results show that the instability of the fusion protein is independent from the Fc origin or IgG subclass and from the peptide sequence used to link the two domains. We also show that a similar instability occurs upon the expression of individual heavy chains of monoclonal antibodies and ScFv-Fc that mimic the "Y"-shape of antibodies but lack the light chain. We propose that in this configuration, steric hindrance between the protein domains leads to physical instability. Indeed, mutations of critical residues located on the Fc dimerization interface allowed the expression of fully stable EPO monomeric Fc-fusion proteins. We discuss the limitations of Fc-fusion technology in N. benthamiana transient expression systems and suggest strategies to optimize the Fc-based scaffolds on their folding and aggregation resistance in order to improve the stability.
Collapse
Affiliation(s)
- Pia Gattinger
- Department of Applied Genetics and Cell Biology, Institute for Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
- Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Shiva Izadi
- Department of Applied Genetics and Cell Biology, Institute for Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
- Department of Plant Genetics and Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Clemens Grünwald-Gruber
- Division of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Somanath Kallolimath
- Department of Applied Genetics and Cell Biology, Institute for Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Alexandra Castilho
- Department of Applied Genetics and Cell Biology, Institute for Plant Biotechnology and Cell Biology, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
- *Correspondence: Alexandra Castilho,
| |
Collapse
|
14
|
Kittur FS, Hung CY, Zhu C, Shajahan A, Azadi P, Thomas MD, Pearce JL, Gruber C, Kallolimath S, Xie J. Glycoengineering tobacco plants to stably express recombinant human erythropoietin with different N-glycan profiles. Int J Biol Macromol 2020; 157:158-169. [PMID: 32348856 PMCID: PMC8349175 DOI: 10.1016/j.ijbiomac.2020.04.199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/31/2020] [Accepted: 04/23/2020] [Indexed: 12/26/2022]
Abstract
Plant-based expression system has many potential advantages to produce biopharmaceuticals, but plants cannot be directly used to express human glycoproteins because of their differences in glycosylation abilities from mammals. To exploit plant-based expression system for producing recombinant human erythropoietin (rhuEPO), we glycoengineered tobacco plants by stably introducing seven to eight mammalian genes including a target human EPO into tobacco in order to generate capacities for β1,4-galactosylation, bisecting N-acetylglucosamine (GlcNAc) and sialylation. Wild type human β1,4-galactosyltransferase gene (GalT) or a chimeric GalT gene (ST/GalT) was co-expressed to produce rhuEPO bearing β1,4-galactose-extended N-glycan chains as well as compare their β1,4-galactosylation efficiencies. Five mammalian genes encoding enzymes/transporter for sialic acid biosynthesis, transport and transfer were co-expressed to build sialylation capacity in plants. The human MGAT3 was co-expressed to produce N-glycan chains with bisecting GlcNAc. Our results demonstrated that the above transgenes were incorporated into tobacco genome and transcribed. ST/GalT was found to be more efficient than GalT for β1,4-galactosylation. Furthermore, co-expressing MGAT3 generated N-glycans likely bearing bisected GlcNAc. However, our current efforts did not result in generating sialylation capacity. Created transgenic plants expressing EPO and ST/GalT could be used to produce rhuEPO with high proportion of β1,4-galactose-extended N-glycan chains for tissue protective purposes.
Collapse
Affiliation(s)
- Farooqahmed S Kittur
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Chiu-Yueh Hung
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Chuanshu Zhu
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA; College of Plant Protection, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Asif Shajahan
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
| | - Michelle D Thomas
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Jackson L Pearce
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Clemens Gruber
- Department of Chemistry, University of Natural Resources and Applied Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Somanath Kallolimath
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Applied Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Jiahua Xie
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA.
| |
Collapse
|
15
|
Kallolimath S, Hackl T, Gahn R, Grünwald-Gruber C, Zich W, Kogelmann B, Lux A, Nimmerjahn F, Steinkellner H. Expression Profiling and Glycan Engineering of IgG Subclass 1-4 in Nicotiana benthamiana. Front Bioeng Biotechnol 2020; 8:825. [PMID: 32793574 PMCID: PMC7393800 DOI: 10.3389/fbioe.2020.00825] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 06/29/2020] [Indexed: 01/19/2023] Open
Abstract
IgG, the main serum immunoglobulin isotype, exists in four subclasses which selectively appear with distinctive glycosylation profiles. However, very little is known about the biological consequences mainly due to the difficulties in the generation of distinct IgG subtypes with targeted glycosylation. Here, we show a comprehensive expression and glycan modulation profiling of IgG variants in planta that are identical in their antigen binding domain but differ in their subclass appearance. While IgG1, 2, and 4 exhibit similar expression levels and purification yields, IgG3 is generated only at low levels due to the in planta degradation of the heavy chain. All IgG subtypes are produced with four distinct N-glycosylation profiles, differing in sugar residues previously shown to impact IgG activities, i.e., galactosylation, sialylation and core fucosylation. Affinity purified IgG variants are shown to be fully assembled to heterodimers but display different biochemical/physical features. All subtypes are equally well amenable to targeted glycosylation, except sialylated IgG4 which frequently accumulates substantial fractions of unusual oligo-mannosidic structures. IgG variants show significant differences in aggregate formation and endotoxin contamination which are eliminated by additional polishing steps (size exclusion chromatography, endotoxin removal treatments). Collectively we demonstrate the generation of 16 IgG variants at high purity and large glycan homogeneity which constitute an excellent toolbox to further study the biological impact of the two main Fc features, subclass and glycosylation.
Collapse
Affiliation(s)
- Somanath Kallolimath
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Thomas Hackl
- Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Raphaela Gahn
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | | | - Wilhelm Zich
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Benjamin Kogelmann
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Anja Lux
- Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Falk Nimmerjahn
- Department Biologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria,*Correspondence: Herta Steinkellner,
| |
Collapse
|
16
|
Kightlinger W, Warfel KF, DeLisa MP, Jewett MC. Synthetic Glycobiology: Parts, Systems, and Applications. ACS Synth Biol 2020; 9:1534-1562. [PMID: 32526139 PMCID: PMC7372563 DOI: 10.1021/acssynbio.0c00210] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Indexed: 12/11/2022]
Abstract
Protein glycosylation, the attachment of sugars to amino acid side chains, can endow proteins with a wide variety of properties of great interest to the engineering biology community. However, natural glycosylation systems are limited in the diversity of glycoproteins they can synthesize, the scale at which they can be harnessed for biotechnology, and the homogeneity of glycoprotein structures they can produce. Here we provide an overview of the emerging field of synthetic glycobiology, the application of synthetic biology tools and design principles to better understand and engineer glycosylation. Specifically, we focus on how the biosynthetic and analytical tools of synthetic biology have been used to redesign glycosylation systems to obtain defined glycosylation structures on proteins for diverse applications in medicine, materials, and diagnostics. We review the key biological parts available to synthetic biologists interested in engineering glycoproteins to solve compelling problems in glycoscience, describe recent efforts to construct synthetic glycoprotein synthesis systems, and outline exemplary applications as well as new opportunities in this emerging space.
Collapse
Affiliation(s)
- Weston Kightlinger
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Tech E136, Evanston, Illinois 60208, United States
- Center
for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Tech B486, Evanston, Illinois 60208, United States
| | - Katherine F. Warfel
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Tech E136, Evanston, Illinois 60208, United States
- Center
for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Tech B486, Evanston, Illinois 60208, United States
| | - Matthew P. DeLisa
- Department
of Microbiology, Cornell University, 123 Wing Drive, Ithaca, New York 14853, United States
- Robert
Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, 120 Olin Hall, Ithaca, New York 14853, United States
- Nancy
E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Weill Hall, Ithaca, New York 14853, United States
| | - Michael C. Jewett
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Tech E136, Evanston, Illinois 60208, United States
- Center
for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Tech B486, Evanston, Illinois 60208, United States
| |
Collapse
|
17
|
Kriechbaum R, Ziaee E, Grünwald‐Gruber C, Buscaill P, van der Hoorn RAL, Castilho A. BGAL1 depletion boosts the level of β-galactosylation of N- and O-glycans in N. benthamiana. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:1537-1549. [PMID: 31837192 PMCID: PMC7292537 DOI: 10.1111/pbi.13316] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/28/2019] [Accepted: 12/05/2019] [Indexed: 05/18/2023]
Abstract
Glyco-design of proteins is a powerful tool in fundamental studies of structure-function relationship and in obtaining profiles optimized for efficacy of therapeutic glycoproteins. Plants, particularly Nicotiana benthamiana, are attractive hosts to produce recombinant glycoproteins, and recent advances in glyco-engineering facilitate customized N-glycosylation of plant-derived glycoproteins. However, with exception of monoclonal antibodies, homogenous human-like β1,4-galactosylation is very hard to achieve in recombinant glycoproteins. Despite significant efforts to optimize the expression of β1,4-galactosyltransferase, many plant-derived glycoproteins still exhibit incomplete processed N-glycans with heterogeneous terminal galactosylation. The most obvious suspects to be involved in trimming terminal galactose residues are β-galactosidases (BGALs) from the glycosyl hydrolase family GH35. To elucidate the so far uncharacterized mechanisms leading to the trimming of terminal galactose residues from glycans of secreted proteins, we studied a N. benthamiana BGAL known to be active in the apoplast (NbBGAL1). Here, we determined the NbBGAL1 subcellular localization, substrate specificity and in planta biological activity. We show that NbBGAL1 can remove β1,4- and β1,3-galactose residues on both N- and O-glycans. Transient BGAL1 down-regulation by RNA interference (RNAi) and BGAL1 depletion by genome editing drastically reduce β-galactosidase activity in N. benthamiana and increase the amounts of fully galactosylated complex N-glycans on several plant-produced glycoproteins. Altogether, our data demonstrate that NbBGAL1 acts on galactosylated complex N-glycans of plant-produced glycoproteins.
Collapse
Affiliation(s)
- Ricarda Kriechbaum
- Department of Applied Genetics and Cell BiologyUniversity of Natural Resources and Life SciencesViennaAustria
| | - Esmaiel Ziaee
- Department of Applied Genetics and Cell BiologyUniversity of Natural Resources and Life SciencesViennaAustria
- Department of Food Science and TechnologyCollege of AgricultureShiraz UniversityShirazIran
| | | | - Pierre Buscaill
- The Plant Chemetics LaboratoryDepartment of Plant SciencesUniversity of OxfordOxfordUK
| | | | - Alexandra Castilho
- Department of Applied Genetics and Cell BiologyUniversity of Natural Resources and Life SciencesViennaAustria
| |
Collapse
|
18
|
Van Landuyt L, Lonigro C, Meuris L, Callewaert N. Customized protein glycosylation to improve biopharmaceutical function and targeting. Curr Opin Biotechnol 2019; 60:17-28. [DOI: 10.1016/j.copbio.2018.11.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 11/30/2018] [Indexed: 11/26/2022]
|
19
|
Kopertekh L, Schiemann J. Transient Production of Recombinant Pharmaceutical Proteins in Plants: Evolution and Perspectives. Curr Med Chem 2019; 26:365-380. [DOI: 10.2174/0929867324666170718114724] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/07/2017] [Accepted: 06/07/2017] [Indexed: 11/22/2022]
Abstract
During the last two decades, the production of pharmaceutical proteins in plants
evolved from proof of concept to established technology adopted by several biotechnological
companies. This progress is particularly based on intensive research starting stable genetic
transformation and moving to transient expression. Due to its advantages in yield and
speed of protein production transient expression platforms became the leading plant-based
manufacturing technology. Current transient expression methods rely on Agrobacteriummediated
delivery of expression vectors into plant cells. In recent years, great advances have
been made in the improvement of expression vectors, host cell engineering as well as in the
development of commercial manufacturing processes. Several GMP-certified large-scale
production facilities exist around the world to utilize agroinfiltration method. A number of
pharmaceutical proteins produced by transient expression are currently in clinical development.
The great potential of transient expression platform in respect to rapid response to
emerging pandemics was demonstrated by the production of experimental ZMapp antibodies
against Ebola virus as well as influenza vaccines. This review is focused on current design,
status and future perspectives of plant transient expression system for the production
of biopharmaceutical proteins.
Collapse
Affiliation(s)
- Lilya Kopertekh
- Federal Research Centre for Cultivated Plants, Institute for Biosafety in Plant Biotechnology, Erwin-Baur- Str. 27, D-06484, Quedlinburg, Germany
| | - Joachim Schiemann
- Federal Research Centre for Cultivated Plants, Institute for Biosafety in Plant Biotechnology, Erwin-Baur- Str. 27, D-06484, Quedlinburg, Germany
| |
Collapse
|
20
|
Top O, Geisen U, Decker EL, Reski R. Critical Evaluation of Strategies for the Production of Blood Coagulation Factors in Plant-Based Systems. FRONTIERS IN PLANT SCIENCE 2019; 10:261. [PMID: 30899272 PMCID: PMC6417376 DOI: 10.3389/fpls.2019.00261] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/19/2019] [Indexed: 05/30/2023]
Abstract
The use of plants as production platforms for pharmaceutical proteins has been on the rise for the past two decades. The first marketed plant-made pharmaceutical, taliglucerase alfa against Gaucher's disease produced in carrot cells by Pfizer/Protalix Biotherapeutics, was approved by the US Food and Drug Administration (FDA) in 2012. The advantages of plant systems are low cost and highly scalable biomass production compared to the fermentation systems, safety compared with other expression systems, as plant-based systems do not produce endotoxins, and the ability to perform complex eukaryotic post-translational modifications, e.g., N-glycosylation that can be further engineered to achieve humanized N-glycan structures. Although bleeding disorders affect only a small portion of the world population, costs of clotting factor concentrates impose a high financial burden on patients and healthcare systems. The majority of patients, ∼75% in the case of hemophilia, have no access to an adequate treatment. The necessity of large-scale and less expensive production of human blood coagulation factors, particularly factors associated with rare bleeding disorders, may be an important area for plant-based systems, as coagulation factors do not fit into the industry-favored production models. In this review, we explore previous studies on recombinant production of coagulation Factor II, VIII, IX, and XIII in different plant species. Production of bioactive FII and FIX in plants was not achieved yet due to complex post-translational modifications, including vitamin K-dependent γ-carboxylation and propeptide removal. Although plant-made FVIII and FXIII showed specific activities, there are no follow-up studies like pre-clinical/clinical trials. Significant progress has been achieved in oral delivery of bioencapsulated FVIII and FIX to induce immune tolerance in murine models of hemophilia A and B, resp. Potential strategies to overcome bottlenecks in the production systems are also addressed in this review.
Collapse
Affiliation(s)
- Oguz Top
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Ulrich Geisen
- Faculty of Medicine, Institute for Clinical Chemistry and Laboratory Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Eva L. Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg im Breisgau, Germany
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg im Breisgau, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg im Breisgau, Germany
| |
Collapse
|
21
|
Montero-Morales L, Steinkellner H. Advanced Plant-Based Glycan Engineering. Front Bioeng Biotechnol 2018; 6:81. [PMID: 29963553 PMCID: PMC6010556 DOI: 10.3389/fbioe.2018.00081] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 05/30/2018] [Indexed: 01/08/2023] Open
Abstract
With respect to biomanufacturing, glycosylation is one of the most addressed post-translational modifications, since it is well-known that the attachment of sugar residues efficiently affects protein homogeneity and functionality. Much effort has been taken into engineering various expression systems to control glycosylation and to generate molecules with targeted sugar profiles. Nevertheless, engineering of N- and O-linked glycans on well-established expression systems remains challenging. On the one side the glycosylation machinery in mammalian cells is hard to control due to its complexity. Most bacteria, on the other side, completely lack such glycan formations, and in general exhibit fundamental differences in their glycosylation abilities. Beyond that, plants generate complex N-glycans typical of higher eukaryotes, but simpler than those produced by mammals. Paradoxically, it seems that the limited glycosylation capacity of plant cells is an advantage for specific glycan manipulations. This review focuses on recent achievements in plant glycan engineering and provides a short outlook on how new developments (in synthetic biology) might have a positive impact.
Collapse
Affiliation(s)
- Laura Montero-Morales
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| |
Collapse
|
22
|
Margolin E, Chapman R, Williamson A, Rybicki EP, Meyers AE. Production of complex viral glycoproteins in plants as vaccine immunogens. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:1531-1545. [PMID: 29890031 PMCID: PMC6097131 DOI: 10.1111/pbi.12963] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/30/2018] [Accepted: 06/05/2018] [Indexed: 05/19/2023]
Abstract
Plant molecular farming offers a cost-effective and scalable approach to the expression of recombinant proteins which has been proposed as an alternative to conventional production platforms for developing countries. In recent years, numerous proofs of concept have established that plants can produce biologically active recombinant proteins and immunologically relevant vaccine antigens that are comparable to those made in conventional expression systems. Driving many of these advances is the remarkable plasticity of the plant proteome which enables extensive engineering of the host cell, as well as the development of improved expression vectors facilitating higher levels of protein production. To date, the only plant-derived viral glycoprotein to be tested in humans is the influenza haemagglutinin which expresses at ~50 mg/kg. However, many other viral glycoproteins that have potential as vaccine immunogens only accumulate at low levels in planta. A critical consideration for the production of many of these proteins in heterologous expression systems is the complexity of post-translational modifications, such as control of folding, glycosylation and disulphide bridging, which is required to reproduce the native glycoprotein structure. In this review, we will address potential shortcomings of plant expression systems and discuss strategies to optimally exploit the technology for the production of immunologically relevant and structurally authentic glycoproteins for use as vaccine immunogens.
Collapse
Affiliation(s)
- Emmanuel Margolin
- Division of Medical VirologyDepartment of PathologyFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
- Institute of Infectious Disease and Molecular MedicineFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
- Biopharming Research UnitDepartment of Molecular and Cell BiologyUniversity of Cape TownCape TownSouth Africa
| | - Ros Chapman
- Division of Medical VirologyDepartment of PathologyFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
- Institute of Infectious Disease and Molecular MedicineFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
| | - Anna‐Lise Williamson
- Division of Medical VirologyDepartment of PathologyFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
- Institute of Infectious Disease and Molecular MedicineFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
| | - Edward P. Rybicki
- Division of Medical VirologyDepartment of PathologyFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
- Institute of Infectious Disease and Molecular MedicineFaculty of Health SciencesUniversity of Cape TownCape TownSouth Africa
- Biopharming Research UnitDepartment of Molecular and Cell BiologyUniversity of Cape TownCape TownSouth Africa
| | - Ann E. Meyers
- Biopharming Research UnitDepartment of Molecular and Cell BiologyUniversity of Cape TownCape TownSouth Africa
| |
Collapse
|
23
|
Rozov SM, Permyakova NV, Deineko EV. Main Strategies of Plant Expression System Glycoengineering for Producing Humanized Recombinant Pharmaceutical Proteins. BIOCHEMISTRY (MOSCOW) 2018; 83:215-232. [PMID: 29625542 DOI: 10.1134/s0006297918030033] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Most the pharmaceutical proteins are derived not from their natural sources, rather their recombinant analogs are synthesized in various expression systems. Plant expression systems, unlike mammalian cell cultures, combine simplicity and low cost of procaryotic systems and the ability for posttranslational modifications inherent in eucaryotes. More than 50% of all human proteins and more than 40% of the currently used pharmaceutical proteins are glycosylated, that is, they are glycoproteins, and their biological activity, pharmacodynamics, and immunogenicity depend on the correct glycosylation pattern. This review examines in detail the similarities and differences between N- and O-glycosylation in plant and mammalian cells, as well as the effect of plant glycans on the activity, pharmacokinetics, immunity, and intensity of biosynthesis of pharmaceutical proteins. The main current strategies of glycoengineering of plant expression systems aimed at obtaining fully humanized proteins for pharmaceutical application are summarized.
Collapse
Affiliation(s)
- S M Rozov
- Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
| | | | | |
Collapse
|
24
|
Ramírez-Alanis IA, Renaud JB, García-Lara S, Menassa R, Cardineau GA. Transient co-expression with three O-glycosylation enzymes allows production of GalNAc- O-glycosylated Granulocyte-Colony Stimulating Factor in N. benthamiana. PLANT METHODS 2018; 14:98. [PMID: 30410568 PMCID: PMC6219069 DOI: 10.1186/s13007-018-0363-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 10/19/2018] [Indexed: 05/03/2023]
Abstract
BACKGROUND Expression of economically relevant proteins in alternative expression platforms, especially plant expression platforms, has gained significant interest in recent years. A special interest in working with plants as bioreactors for the production of pharmaceutical proteins is related to low production costs, product safety and quality. Among the different properties that plants can also offer for the production of recombinant proteins, protein glycosylation is crucial since it may have an impact on pharmaceutical functionality and/or stability. RESULTS The pharmaceutical glycoprotein human Granulocyte-Colony Stimulating Factor was transiently expressed in Nicotiana benthamiana plants and subjected to mammalian-specific mucin-type O-glycosylation by co-expressing the pharmaceutical protein together with the glycosylation machinery responsible for such post-translational modification. CONCLUSIONS The pharmaceutical glycoprotein human Granulocyte-Colony Stimulating Factor can be expressed in N. benthamiana plants via agroinfiltration with its native mammalian-specific mucin-type O-glycosylation.
Collapse
Affiliation(s)
- Israel A. Ramírez-Alanis
- School of Engineering and Sciences, Tecnologico de Monterrey, Campus Monterrey, Av. Eugenio Garza Sada 2501 Sur, C.P. 64849 Monterrey, NL Mexico
| | | | - Silverio García-Lara
- School of Engineering and Sciences, Tecnologico de Monterrey, Campus Monterrey, Av. Eugenio Garza Sada 2501 Sur, C.P. 64849 Monterrey, NL Mexico
| | - Rima Menassa
- Agriculture and Agri-Food Canada, London, ON Canada
- Department of Biology, University of Western Ontario, London, ON Canada
| | - Guy A. Cardineau
- School of Engineering and Sciences, Tecnologico de Monterrey, Campus Monterrey, Av. Eugenio Garza Sada 2501 Sur, C.P. 64849 Monterrey, NL Mexico
- Arizona State University, Phoenix, AZ 85004-4467 USA
| |
Collapse
|
25
|
Glyco-Engineering of Plant-Based Expression Systems. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2018; 175:137-166. [PMID: 30069741 DOI: 10.1007/10_2018_76] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Most secreted proteins in eukaryotes are glycosylated, and after a number of common biosynthesis steps the glycan structures mature in a species-dependent manner. Therefore, human therapeutic proteins produced in plants often carry plant-like rather than human-like glycans, which can affect protein stability, biological function, and immunogenicity. The glyco-engineering of plant-based expression systems began as a strategy to eliminate plant-like glycans and produce human proteins with authentic or at least compatible glycan structures. The precise replication of human glycans is challenging, owing to the absence of a pathway in plants for the synthesis of sialylated proteins and the necessary precursors, but this can now be achieved by the coordinated expression of multiple human enzymes. Although the research community has focused on the removal of plant glycans and their replacement with human counterparts, the presence of plant glycans on proteins can also provide benefits, such as boosting the immunogenicity of some vaccines, facilitating the interaction between therapeutic proteins and their receptors, and increasing the efficacy of antibody effector functions. Graphical Abstract Typical structures of native mammalian and plant glycans with symbols indicating sugar residues identified by their short form and single-letter codes. Both glycans contain fucose, albeit with different linkages.
Collapse
|
26
|
Vanier G, Stelter S, Vanier J, Hempel F, Maier UG, Lerouge P, Ma J, Bardor M. Alga-Made Anti-Hepatitis B Antibody Binds to Human Fcγ Receptors. Biotechnol J 2017; 13:e1700496. [DOI: 10.1002/biot.201700496] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 11/20/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Gaëtan Vanier
- Normandie Univ, UNIROUEN; Laboratoire Glycobiologie et Matrice Extracellulaire Végétale; Rouen 76000 France
| | - Szymon Stelter
- Molecular Immunology Unit, Institute for Infection and Immunity; St. George's University of London Cranmer Terrace; London SW17 0RE UK
| | - Jessica Vanier
- Normandie Univ, UNIROUEN; Laboratoire Glycobiologie et Matrice Extracellulaire Végétale; Rouen 76000 France
| | - Franziska Hempel
- LOEWE Center for Synthetic Microbiology; Philipps-Universität Marburg; Marburg 35032 Germany
| | - Uwe G. Maier
- LOEWE Center for Synthetic Microbiology; Philipps-Universität Marburg; Marburg 35032 Germany
- Department of Cell Biology; Philipps-Universität Marburg; Marburg 35032 Germany
| | - Patrice Lerouge
- Normandie Univ, UNIROUEN; Laboratoire Glycobiologie et Matrice Extracellulaire Végétale; Rouen 76000 France
| | - Julian Ma
- Molecular Immunology Unit, Institute for Infection and Immunity; St. George's University of London Cranmer Terrace; London SW17 0RE UK
| | - Muriel Bardor
- Normandie Univ, UNIROUEN; Laboratoire Glycobiologie et Matrice Extracellulaire Végétale; Rouen 76000 France
- Institut Universitaire de France (I.U.F.) 1; rue Descartes Paris Cedex 05 75231 France
| |
Collapse
|
27
|
Schoberer J, Strasser R. Plant glyco-biotechnology. Semin Cell Dev Biol 2017; 80:133-141. [PMID: 28688929 DOI: 10.1016/j.semcdb.2017.07.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 07/03/2017] [Accepted: 07/04/2017] [Indexed: 11/17/2022]
Abstract
Glycosylation is an important protein modification in all eukaryotes. Whereas the early asparagine-linked glycosylation (N-glycosylation) and N-glycan processing steps in the endoplasmic reticulum are conserved between mammals and plants, the maturation of complex N-glycans in the Golgi apparatus differs considerably. Due to a restricted number of Golgi-resident N-glycan processing enzymes and the absence of nucleotide sugars such as CMP-N-acetylneuraminic acid, plants produce only a limited repertoire of different N-glycan structures. Moreover, mammalian mucin-type O-glycosylation of serine or threonine residues has not been described in plants and the required machinery is not encoded in their genome which enables de novo build-up of the pathway. As a consequence, plants are very well-suited for the production of homogenous N- and O-glycans and are increasingly used for the production of recombinant glycoproteins with custom-made glycans that may result in the generation of biopharmaceuticals with improved therapeutic potential.
Collapse
Affiliation(s)
- Jennifer Schoberer
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria.
| |
Collapse
|
28
|
Abstract
Sialic acids (Sias) are abundant terminal modifications of protein-linked glycans. A unique feature of Sia, compared with other monosaccharides, is the formation of linear homo-polymers, with its most complex form polysialic acid (polySia). Sia and polySia mediate diverse biological functions and have great potential for therapeutic use. However, technological hurdles in producing defined protein sialylation due to the enormous structural diversity render their precise investigation a challenge. Here, we describe a plant-based expression platform that enables the controlled in vivo synthesis of sialylated structures with different interlinkages and degree of polymerization (DP). The approach relies on a combination of stably transformed plants with transient expression modules. By the introduction of multigene vectors carrying the human sialylation pathway into glycosylation-destructed mutants, transgenic plants that sialylate glycoproteins in α2,6- or α2,3-linkage were generated. Moreover, by the transient coexpression of human α2,8-polysialyltransferases, polySia structures with a DP >40 were synthesized in these plants. Importantly, plant-derived polySia are functionally active, as demonstrated by a cell-based cytotoxicity assay and inhibition of microglia activation. This pathway engineering approach enables experimental investigations of defined sialylation and facilitates a rational design of glycan structures with optimized biotechnological functions.
Collapse
|
29
|
Burlakovskiy MS, Yemelyanov VV, Lutova LA. Plant Based Bioreactors of Recombinant Cytokines (Review). APPL BIOCHEM MICRO+ 2016; 52:121-137. [PMID: 32214409 PMCID: PMC7087682 DOI: 10.1134/s0003683816020034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Indexed: 01/16/2023]
Abstract
Cytokines are a family of signaling polypeptides involved in intercellular interactions in the process of the immune response, as well as in the regulation of a number of normal physiological functions. Cytokines are used in medicine for the treatment of cancer, immune disorders, viral infections, and other socially significant diseases, but the extent of their use is limited by the high production cost of the active agent. The development of this area of pharmacology is associated with the success of genetic engineering, which allows the production of significant amounts of protein by transgenic organisms. The review discusses the latest advances in the production of various cytokines with the use of genetically modified plants.
Collapse
Affiliation(s)
- M. S. Burlakovskiy
- Biology Faculty, St. Petersburg State University, St. Petersburg, 199034 Russia
| | - V. V. Yemelyanov
- Biology Faculty, St. Petersburg State University, St. Petersburg, 199034 Russia
| | - L. A. Lutova
- Biology Faculty, St. Petersburg State University, St. Petersburg, 199034 Russia
| |
Collapse
|
30
|
Giddens JP, Lomino JV, Amin MN, Wang LX. Endo-F3 Glycosynthase Mutants Enable Chemoenzymatic Synthesis of Core-fucosylated Triantennary Complex Type Glycopeptides and Glycoproteins. J Biol Chem 2016; 291:9356-70. [PMID: 26966183 DOI: 10.1074/jbc.m116.721597] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Indexed: 11/06/2022] Open
Abstract
Chemoenzymatic synthesis is emerging as a promising approach to the synthesis of homogeneous glycopeptides and glycoproteins highly demanded for functional glycomics studies, but its generality relies on the availability of a range of enzymes with high catalytic efficiency and well defined substrate specificity. We describe in this paper the discovery of glycosynthase mutants derived from Elizabethkingia meningoseptica endoglycosidase F3 (Endo-F3) of the GH18 family, which are devoid of the inherent hydrolytic activity but are able to take glycan oxazolines for transglycosylation. Notably, the Endo-F3 D165A and D165Q mutants demonstrated high acceptorsubstrate specificity toward α1,6-fucosyl-GlcNAc-Asn or α1,6-fucosyl-GlcNAc-polypeptide in transglycosylation, enabling a highly convergent synthesis of core-fucosylated, complex CD52 glycopeptide antigen. The Endo-F3 mutants were able to use both bi- and triantennary glycan oxazolines as substrates for transglycosylation, in contrast to previously reported endoglycosidases derived from Endo-S, Endo-M, Endo-D, and Endo-A mutants that could not recognize triantennary N-glycans. Using rituximab as a model system, we have further demonstrated that the Endo-F3 mutants are highly efficient for glycosylation remodeling of monoclonal antibodies to produce homogeneous intact antibody glycoforms. Interestingly, the new triantennary glycan glycoform of antibody showed much higher affinity for galectin-3 than that of the commercial antibody. The Endo-F3 mutants represent the first endoglycosidase-based glycosynthases capable of transferring triantennary complex N-glycans, which would be very useful for glycoprotein synthesis and glycosylation remodeling of antibodies.
Collapse
Affiliation(s)
- John P Giddens
- From the Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland 21201 and the Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Joseph V Lomino
- From the Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland 21201 and
| | - Mohammed N Amin
- From the Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland 21201 and the Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Lai-Xi Wang
- From the Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland 21201 and the Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| |
Collapse
|
31
|
Wilbers RHP, Westerhof LB, Reuter LJ, Castilho A, van Raaij DR, Nguyen DL, Lozano-Torres JL, Smant G, Hokke CH, Bakker J, Schots A. The N-glycan on Asn54 affects the atypical N-glycan composition of plant-produced interleukin-22, but does not influence its activity. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:670-81. [PMID: 26059044 DOI: 10.1111/pbi.12414] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/14/2015] [Accepted: 05/03/2015] [Indexed: 05/27/2023]
Abstract
Human interleukin-22 (IL-22) is a member of the IL-10 cytokine family that has recently been shown to have major therapeutic potential. IL-22 is an unusual cytokine as it does not act directly on immune cells. Instead, IL-22 controls the differentiation, proliferation and antimicrobial protein expression of epithelial cells, thereby maintaining epithelial barrier function. In this study, we transiently expressed human IL-22 in Nicotiana benthamiana plants and investigated the role of N-glycosylation on protein folding and biological activity. Expression levels of IL-22 were up to 5.4 μg/mg TSP, and N-glycan analysis revealed the presence of the atypical Lewis A structure. Surprisingly, upon engineering of human-like N-glycans on IL-22 by co-expressing mouse FUT8 in ΔXT/FT plants a strong reduction in Lewis A was observed. Also, core α1,6-fucoylation did not improve the biological activity of IL-22. The combination of site-directed mutagenesis of Asn54 and in vivo deglycosylation with PNGase F also revealed that N-glycosylation at this position is not required for proper protein folding. However, we do show that the presence of a N-glycan on Asn54 contributes to the atypical N-glycan composition of plant-produced IL-22 and influences the N-glycan composition of N-glycans on other positions. Altogether, our data demonstrate that plants offer an excellent tool to investigate the role of N-glycosylation on folding and activity of recombinant glycoproteins, such as IL-22.
Collapse
Affiliation(s)
- Ruud H P Wilbers
- Plant Sciences Department, Laboratory of Nematology, Wageningen University and Research Centre, Wageningen, The Netherlands
| | - Lotte B Westerhof
- Plant Sciences Department, Laboratory of Nematology, Wageningen University and Research Centre, Wageningen, The Netherlands
| | - Lauri J Reuter
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Alexandra Castilho
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Debbie R van Raaij
- Plant Sciences Department, Laboratory of Nematology, Wageningen University and Research Centre, Wageningen, The Netherlands
| | - Dieu-Linh Nguyen
- Department of Parasitology, Parasite Glycobiology Group, Leiden University Medical Center, Leiden, The Netherlands
| | - Jose L Lozano-Torres
- Plant Sciences Department, Laboratory of Nematology, Wageningen University and Research Centre, Wageningen, The Netherlands
| | - Geert Smant
- Plant Sciences Department, Laboratory of Nematology, Wageningen University and Research Centre, Wageningen, The Netherlands
| | - Cornelis H Hokke
- Department of Parasitology, Parasite Glycobiology Group, Leiden University Medical Center, Leiden, The Netherlands
| | - Jaap Bakker
- Plant Sciences Department, Laboratory of Nematology, Wageningen University and Research Centre, Wageningen, The Netherlands
| | - Arjen Schots
- Plant Sciences Department, Laboratory of Nematology, Wageningen University and Research Centre, Wageningen, The Netherlands
| |
Collapse
|
32
|
Castilho A, Steinkellner H. Transient Expression of Mammalian Genes in N. benthamiana to Modulate N-Glycosylation. Methods Mol Biol 2016; 1385:99-113. [PMID: 26614284 DOI: 10.1007/978-1-4939-3289-4_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Nicotiana benthamiana has shown great success as a platform for the production of recombinant proteins. Here, we describe methods to transiently express high levels of recombinant proteins and simultaneously modulate their glycosylation pattern toward human-like structures. The method aims to generate recombinant proteins with a targeted largely homogeneous glycosylation profile for structure-function studies.
Collapse
Affiliation(s)
- Alexandra Castilho
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria.
| |
Collapse
|
33
|
Chen R. The sweet branch of metabolic engineering: cherry-picking the low-hanging sugary fruits. Microb Cell Fact 2015; 14:197. [PMID: 26655367 PMCID: PMC4674990 DOI: 10.1186/s12934-015-0389-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/25/2015] [Indexed: 02/08/2023] Open
Abstract
In the first science review on the then nascent Metabolic Engineering field in 1991, Dr. James E. Bailey described how improving erythropoietin (EPO) glycosylation can be achieved via metabolic engineering of Chinese hamster ovary (CHO) cells. In the intervening decades, metabolic engineering has brought sweet successes in glycoprotein engineering, including antibodies, vaccines, and other human therapeutics. Today, not only eukaryotes (CHO, plant, insect, yeast) are being used for manufacturing protein therapeutics with human-like glycosylation, newly elucidated bacterial glycosylation systems are enthusiastically embraced as potential breakthrough to revolutionize the biopharmaceutical industry. Notwithstanding these excitement in glycoprotein, the sweet metabolic engineering reaches far beyond glycoproteins. Many different types of oligo- and poly-saccharides are synthesized with metabolically engineered cells. For example, several recombinant hyaluronan bioprocesses are now in commercial production, and the titer of 2′-fucosyllactose, the most abundant fucosylated trisaccharide in human milk, reaches over 20 g/L with engineered E. coli cells. These successes represent only the first low hanging fruits, which have been appreciated scientifically, medically and fortunately, commercially as well. As one of the four building blocks of life, sugar molecules permeate almost all aspects of life. They are also unique in being intimately associated with all major types of biopolymers (including DNA/RNA, proteins, lipids) meanwhile they stand alone as bioactive polysaccharides, or free soluble oligosaccharides. As such, all sugar moieties in biological components, small or big and free or bound, are important targets for metabolic engineering. Opportunities abound at the interface of glycosciences and metabolic engineering. Continued investment and successes in this branch of metabolic engineering will make vastly diverse sugar-containing molecules (a.k.a. glycoconjugates) available for biomedical applications, sustainable technology development, and as invaluable tools for basic scientific research. This short review focuses on the most recent development in the field, with emphasis on the synthesis technology for glycoprotein, polysaccharide, and oligosaccharide.
Collapse
Affiliation(s)
- Rachel Chen
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, NW, Atlanta, GA, 30332-0100, USA.
| |
Collapse
|
34
|
Reski R, Parsons J, Decker EL. Moss-made pharmaceuticals: from bench to bedside. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:1191-8. [PMID: 26011014 PMCID: PMC4736463 DOI: 10.1111/pbi.12401] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/16/2015] [Accepted: 04/17/2015] [Indexed: 05/10/2023]
Abstract
Over the past two decades, the moss Physcomitrella patens has been developed from scratch to a model species in basic research and in biotechnology. A fully sequenced genome, outstanding possibilities for precise genome-engineering via homologous recombination (knockout moss), a certified GMP production in moss bioreactors, successful upscaling to 500 L wave reactors, excellent homogeneity of protein glycosylation, remarkable batch-to-batch stability and a safe cryopreservation for master cell banking are some of the key features of the moss system. Several human proteins are being produced in this system as potential biopharmaceuticals. Among the products are tumour-directed monoclonal antibodies with enhanced antibody-dependent cytotoxicity (ADCC), vascular endothelial growth factor (VEGF), complement factor H (FH), keratinocyte growth factor (FGF7/KGF), epidermal growth factor (EGF), hepatocyte growth factor (HGF), asialo-erythropoietin (asialo-EPO, AEPO), alpha-galactosidase (aGal) and beta-glucocerebrosidase (GBA). Further, an Env-derived multi-epitope HIV protein as a candidate vaccine was produced, and first steps for a metabolic engineering of P. patens have been made. Some of the recombinant biopharmaceuticals from moss bioreactors are not only similar to those produced in mammalian systems such as CHO cells, but are of superior quality (biobetters). The first moss-made pharmaceutical, aGal to treat Morbus Fabry, is in clinical trials.
Collapse
Affiliation(s)
- Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
- FRIAS - Freiburg Institute for Advanced Studies, Freiburg, Germany
- BIOSS - Centre for Biological Signalling Studies, Freiburg, Germany
| | - Juliana Parsons
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Eva L Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| |
Collapse
|
35
|
Saberianfar R, Joensuu JJ, Conley AJ, Menassa R. Protein body formation in leaves of Nicotiana benthamiana: a concentration-dependent mechanism influenced by the presence of fusion tags. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:927-37. [PMID: 25640969 DOI: 10.1111/pbi.12329] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 12/03/2014] [Accepted: 12/15/2014] [Indexed: 05/20/2023]
Abstract
Protein bodies (PBs) are endoplasmic reticulum (ER) derived organelles originally found in seeds whose function is to accumulate seed storage proteins. It has been shown that PB formation is not limited to seeds and green fluorescent protein (GFP) fused to either elastin-like polypeptide (ELP) or hydrophobin (HFBI) fusion tags induce the formation of PBs in leaves of N. benthamiana. In this study, we compared the ELP- and HFBI-induced PBs and showed that ELP-induced PBs are larger than HFBI-induced PBs. The size of ELP- and HFBI-induced PBs increased over time along with the accumulation levels of their fused protein. Our results show that PB formation is a concentration-dependent mechanism in which proteins accumulating at levels higher than 0.2% of total soluble protein are capable of inducing PBs in vivo. Our results show that the presence of fusion tags is not necessary for the formation of PBs, but affects the distribution pattern and size of PBs. This was confirmed by PBs induced by fluorescent proteins as well as fungal xylanases. We noticed that in the process of PB formation, secretory and ER-resident molecules are passively sequestered into the lumen of PBs. We propose to use this property of PBs as a tool to increase the accumulation levels of erythropoietin and human interleukin-10 by co-expression with PB-inducing proteins.
Collapse
Affiliation(s)
- Reza Saberianfar
- Department of Biology, Western University, London, ON, Canada
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, ON, Canada
| | | | | | - Rima Menassa
- Department of Biology, Western University, London, ON, Canada
- Southern Crop Protection and Food Research Centre, Agriculture and Agri-Food Canada, London, ON, Canada
| |
Collapse
|
36
|
Abstract
INTRODUCTION Glycans are increasingly important in the development of new biopharmaceuticals with optimized efficacy, half-life, and antigenicity. Current expression platforms for recombinant glycoprotein therapeutics typically do not produce homogeneous glycans and frequently display non-human glycans which may cause unwanted side effects. To circumvent these issues, glyco-engineering has been applied to different expression systems including mammalian cells, insect cells, yeast, and plants. AREAS COVERED This review summarizes recent developments in glyco-engineering focusing mainly on in vivo expression systems for recombinant proteins. The highlighted strategies aim at producing glycoproteins with homogeneous N- and O-linked glycans of defined composition. EXPERT OPINION Glyco-engineering of expression platforms is increasingly recognized as an important strategy to improve biopharmaceuticals. A better understanding and control of the factors leading to glycan heterogeneity will allow simplified production of recombinant glycoprotein therapeutics with less variation in terms of glycosylation. Further technological advances will have a major impact on manufacturing processes and may provide a completely new class of glycoprotein therapeutics with customized functions.
Collapse
Affiliation(s)
- Martina Dicker
- a 1 University of Natural Resources and Life Sciences , Department of Applied Genetics and Cell Biology , Muthgasse 18, Vienna, Austria
| | - Richard Strasser
- b 2 University of Natural Resources and Life Sciences, Department of Applied Genetics and Cell Biology , Muthgasse 18, Vienna, Austria +43 1 47654 6705 ; +43 1 47654 6392 ;
| |
Collapse
|
37
|
Corfield AP, Berry M. Glycan variation and evolution in the eukaryotes. Trends Biochem Sci 2015; 40:351-9. [PMID: 26002999 DOI: 10.1016/j.tibs.2015.04.004] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/16/2015] [Accepted: 04/27/2015] [Indexed: 11/18/2022]
Abstract
In this review, we document the evolution of common glycan structures in the eukaryotes, and illustrate the considerable variety of oligosaccharides existing in these organisms. We focus on the families of N- and O-glycans, glycosphingolipids, glycosaminoglycans, glycosylphosphatidylinositol (GPI) anchors, sialic acids (Sias), and cytoplasmic and nuclear glycans. We also outline similar and divergent aspects of the glycans during evolution within the groups, which include inter- and intraspecies differences, molecular mimicry, viral glycosylation adaptations, glycosyltransferase specificity relating to function, and the natural dynamism powering these events. Finally, we present an overview of the patterns of glycosylation found within the groups comprising the Eukaryota, namely the Deuterostomia, Fungi, Viridiplantae, Nematoda, and Arthropoda.
Collapse
Affiliation(s)
- Anthony P Corfield
- Mucin Research Group, University of Bristol, School of Clinical Sciences, Bristol Royal Infirmary, Bristol, BS2 8HW, UK.
| | - Monica Berry
- University of Bristol, School of Physics, Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol, BS8 1FD, UK.
| |
Collapse
|
38
|
Kittur FS, Lalgondar M, Hung CY, Sane DC, Xie J. C-Terminally fused affinity Strep-tag II is removed by proteolysis from recombinant human erythropoietin expressed in transgenic tobacco plants. PLANT CELL REPORTS 2015; 34:507-16. [PMID: 25504272 PMCID: PMC4329255 DOI: 10.1007/s00299-014-1730-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 12/03/2014] [Accepted: 12/05/2014] [Indexed: 06/04/2023]
Abstract
KEY MESSAGE C -terminally fused Strep -tag II is removed from rhuEPO expressed in tobacco plants. The finding suggests that direct fusion of purification tags at the C -terminus of rhuEPO should be avoided. Asialo-erythropoietin (asialo-EPO), a desialylated form of EPO, is a potent tissue-protective agent. Recently, we and others have exploited a low-cost plant-based expression system to produce recombinant human asialo-EPO (asialo-rhuEPO(P)). To facilitate purification from plant extracts, Strep-tag II was engineered at the C-terminus of EPO. Although asialo-rhuEPO(P) was efficiently expressed in transgenic tobacco plants, affinity purification based on Strep -tag II did not result in the recovery of the protein. In this study, we investigated the stability of Strep-tag II tagged asialo-rhuEPO(P) expressed in tobacco plants to understand whether this fused tag is cleaved or inaccessible. Sequencing RT-PCR products confirmed that fused DNA sequences encoding Strep-tag II were properly transcribed, and three-dimensional protein structure model revealed that the tag must be fully accessible. However, Western blot analysis of leaf extracts and purified asialo-rhuEPO(P) revealed that the Strep-tag II was absent on the protein. Additionally, no peptide fragment containing Strep-tag II was identified in the LC-MS/MS analysis of purified protein further supporting that the affinity tag was absent on asialo-rhuEPO(P). However, Strep-tag II was detected on asialo-rhuEPO(P) that was retained in the endoplasmic reticulum, suggesting that the Strep-tag II is removed during protein secretion or extraction. These findings together with recent reports that C-terminally fused Strep-tag II or IgG Fc domain are also removed from EPO in tobacco plants, suggest that its C-terminus may be highly susceptible to proteolysis in tobacco plants. Therefore, direct fusion of purification tags at the C-terminus of EPO should be avoided while expressing it in tobacco plants.
Collapse
Affiliation(s)
- Farooqahmed S. Kittur
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Mallikarjun Lalgondar
- Center for Agribusiness Excellence, Tarleton State University, Stephenville, TX 76402, USA
| | - Chiu-Yueh Hung
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - David C. Sane
- Carilion Clinic and Virginia Tech Carilion School of Medicine, Roanoke VA 24014, USA
| | - Jiahua Xie
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA. 1801 Fayetteville Street, Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA; Phone:+1 919 530 6705; Fax: +1 919 530 6600
| |
Collapse
|
39
|
Loos A, Castilho A. Transient Glyco-Engineering of N. benthamiana Aiming at the Synthesis of Multi-antennary Sialylated Proteins. Methods Mol Biol 2015; 1321:233-48. [PMID: 26082227 DOI: 10.1007/978-1-4939-2760-9_17] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recombinantly produced therapeutic proteins bring benefits to patients and production companies alike. However, due to high production costs the potential of this technology cannot be fully tapped and therefor safe, scalable, and economic alternatives to the standard mammalian cell culture-based manufacturing systems are needed. Plant-based expression systems with their current technological advances constitute such an alternative. Many recombinant biopharmaceuticals are glycoproteins and their structural properties and pharmacokinetics are strongly influenced by their glycosylation profile. Differences in glycosylation between plants and mammals can for this reason result in different therapeutic efficacies. In particular, low levels of sialylation may lead to a short serum half-life of therapeutic proteins and nonhuman types of glycosylation can induce degradation and immunogenic responses. Controlling glycosylation of plant-derived therapeutics is therefore fundamental to enhance their efficacy and eliminate possible adverse effects caused by non-authentic glycosylation. Here we describe methods to transiently express high levels of recombinant proteins in Nicotiana benthamiana and simultaneously modulate their glycosylation pattern towards the synthesis of highly sialylated humanlike structures.
Collapse
Affiliation(s)
- Andreas Loos
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | | |
Collapse
|
40
|
Abstract
Plants are being developed as a cost-effective production system for biopharmaceuticals in large quantities. Although plants properly fold and assemble complex proteins from human origin, one issue that needs to be addressed is their glycan structure. In the past years we have been witnessing outstanding results in targeted manipulation of the plant N-glycosylation pathway allowing recombinant proteins to be produced with human-type oligosaccharides at large homogeneity. This opens new possibility in manufacturing next-generation biopharmaceuticals.This review presents a variety of technologies and strategies that are being employed to engineer the plant N-glycosylation, thus pointing to the enormous potential of plants being used as a novel production system with unique features and possibilities.
Collapse
|
41
|
Kittur FS, Arthur E, Nguyen M, Hung CY, Sane DC, Xie J. Two-step purification procedure for recombinant human asialoerythropoietin expressed in transgenic plants. Int J Biol Macromol 2015; 72:1111-6. [PMID: 25450830 PMCID: PMC4260996 DOI: 10.1016/j.ijbiomac.2014.10.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 10/13/2014] [Accepted: 10/15/2014] [Indexed: 12/19/2022]
Abstract
Asialoerythropoietin (asialo-EPO) is a desialylated form of human glycoprotein hormone erythropoietin (EPO), which has been reported to be neuro-, cardio-, and renoprotective in animal models of organ injuries. Since the current method of production of asialo-EPO from mammalian cell-made recombinant human EPO (rhuEPO(M)) by enzymatic desialylation is not commercially viable, we and others used plant-based expression systems to produce recombinant human asialo-EPO (asialo-rhuEPO(P)). Despite achieving high expression levels in plants, its purification from plant extracts has remained a greater challenge, which has prevented studying its tissue-protective effects and translating it into clinical practice. In this study, a procedure was developed to purify asialo-rhuEPO(P) from transgenic tobacco leaf tissues in two steps: ion-exchange chromatography based on its high pI (8.75) to separate it from acidic plant proteins, and immunoaffinity chromatography to obtain pure asialo-rhuEPO(P). Using this process, up to 31% of the asialo-rhuEPO(P) could be recovered to near homogeneity from plant extracts. This work demonstrates that asialo-rhuEPO(P) expressed in tobacco plants could be purified in high yield and purity using minimal steps, which might be suitable for scale-up. Furthermore, the ion-exchange chromatography step together with the use of protein-specific antibody column could be used to purify a wide variety of basic recombinant proteins from transgenic leaf tissues.
Collapse
Affiliation(s)
- Farooqahmed S Kittur
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Elena Arthur
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Maikhanh Nguyen
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - Chiu-Yueh Hung
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA
| | - David C Sane
- Carilion Clinic and Virginia Tech Carilion School of Medicine, Roanoke, VA 24014, USA
| | - Jiahua Xie
- Department of Pharmaceutical Sciences, Biomanufacturing Research Institute & Technology Enterprise, North Carolina Central University, Durham, NC 27707, USA.
| |
Collapse
|
42
|
Castilho A, Windwarder M, Gattinger P, Mach L, Strasser R, Altmann F, Steinkellner H. Proteolytic and N-glycan processing of human α1-antitrypsin expressed in Nicotiana benthamiana. PLANT PHYSIOLOGY 2014; 166:1839-51. [PMID: 25355867 PMCID: PMC4256845 DOI: 10.1104/pp.114.250720] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 10/28/2014] [Indexed: 05/19/2023]
Abstract
Plants are increasingly being used as an expression system for complex recombinant proteins. However, our limited knowledge of the intrinsic factors that act along the secretory pathway, which may compromise product integrity, renders process design difficult in some cases. Here, we pursued the recombinant expression of the human protease inhibitor α1-antitrypsin (A1AT) in Nicotiana benthamiana. This serum protein undergoes intensive posttranslational modifications. Unusually high levels of recombinant A1AT were expressed in leaves (up to 6 mg g(-1) of leaf material) in two forms: full-length A1AT located in the endoplasmic reticulum displaying inhibitory activity, and secreted A1AT processed in the reactive center loop, thus rendering it unable to interact with target proteinases. We found that the terminal protein processing is most likely a consequence of the intrinsic function of A1AT (i.e. its interaction with proteases [most likely serine proteases] along the secretory pathway). Secreted A1AT carried vacuolar-type paucimannosidic N-glycans generated by the activity of hexosaminidases located in the apoplast/plasma membrane. Notwithstanding, an intensive glycoengineering approach led to secreted A1AT carrying sialylated N-glycan structures largely resembling its serum-derived counterpart. In summary, we elucidate unique insights in plant glycosylation processes and show important aspects of postendoplasmic reticulum protein processing in plants.
Collapse
Affiliation(s)
- Alexandra Castilho
- Departments of Applied Genetics and Cell Biology (A.C., P.G., L.M., R.S., H.S.) andChemistry (M.W., F.A.), University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Markus Windwarder
- Departments of Applied Genetics and Cell Biology (A.C., P.G., L.M., R.S., H.S.) andChemistry (M.W., F.A.), University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Pia Gattinger
- Departments of Applied Genetics and Cell Biology (A.C., P.G., L.M., R.S., H.S.) andChemistry (M.W., F.A.), University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Lukas Mach
- Departments of Applied Genetics and Cell Biology (A.C., P.G., L.M., R.S., H.S.) andChemistry (M.W., F.A.), University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Richard Strasser
- Departments of Applied Genetics and Cell Biology (A.C., P.G., L.M., R.S., H.S.) andChemistry (M.W., F.A.), University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Friedrich Altmann
- Departments of Applied Genetics and Cell Biology (A.C., P.G., L.M., R.S., H.S.) andChemistry (M.W., F.A.), University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Herta Steinkellner
- Departments of Applied Genetics and Cell Biology (A.C., P.G., L.M., R.S., H.S.) andChemistry (M.W., F.A.), University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| |
Collapse
|
43
|
Mohammadzadeh S, Khabiri A, Roohvand F, Memarnejadian A, Salmanian AH, Ajdary S, Ehsani P. Enhanced-Transient Expression of Hepatitis C Virus Core Protein in Nicotiana tabacum, a Protein With Potential Clinical Applications. HEPATITIS MONTHLY 2014; 14:e20524. [PMID: 25598788 PMCID: PMC4286711 DOI: 10.5812/hepatmon.20524] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 09/29/2014] [Accepted: 10/23/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hepatitis C virus (HCV) is major cause of liver cirrhosis in humans. HCV capsid (core) protein (HCVcp) is a highly demanded antigen for various diagnostic, immunization and pathogenesis studies. Plants are considered as an expression system for producing safe and inexpensive biopharmaceutical proteins. Although invention of transgenic (stable) tobacco plants expressing HCVcp with proper antigenic properties was recently reported, no data for "transient-expression" that is currently the method of choice for rapid, simple and lower-priced protein expression in plants is available for HCVcp. OBJECTIVES The purpose of this study was to design a highly codon-optimized HCVcp gene for construction of an efficient transient-plant expression system for production of HCVcp with proper antigenic properties in a regional tobacco plant (Iranian Jafarabadi-cultivar) by evaluation of different classes of vectors and suppression of gene-silencing in tobacco. MATERIALS AND METHODS A codon-optimized gene encoding the Kozak sequence, 6xHis-tag, HCVcp (1-122) and KDEL peptide in tandem (from N- to C-terminal) was designed and inserted into potato virus-X (PVX) and classic pBI121 binary vectors in separate cloning reactions. The resulted recombinant plasmids were transferred into Agrobacterium tumefaciens and vacuum infiltrated into tobacco leaves. The effect of gene silencing suppressor P19 protein derived from tomato bushy stunt virus on the expression yield of HCVcp by each construct was also evaluated by co-infiltration in separate groups. The expressed HCVcp was evaluated by dot and western blotting and ELISA assays. RESULTS The codon-optimized gene had an increased adaptation index value (from 0.65 to 0.85) and reduced GC content (from 62.62 to 51.05) in tobacco and removed the possible deleterious effect of "GGTAAG" splice site in native HCVcp. Blotting assays via specific antibodies confirmed the expression of the 15 kDa HCVcp. The expression level of HCVcp was enhanced by 4-5 times in P19 co-agroinfiltrated plants with better outcomes for PVX, compared to pBI121 vector (0.022% versus 0.019% of the total soluble protein). The plant-derived HCVcp (pHCVcp) could properly identify the HCVcp antibody in HCV-infected human sera compared to Escherichia coli-derived HCVcp (eHCVcp), indicating its potential for diagnostic/immunization applications. CONCLUSIONS By employment of gene optimization strategies, use of viral-based vectors and suppression of plant-derived gene silencing effect, efficient transient expression of HCVcp in tobacco with proper antigenic properties could be possible.
Collapse
Affiliation(s)
- Sara Mohammadzadeh
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, IR Iran
| | - Alireza Khabiri
- Department of Mycology, Pasteur Institute of Iran, Tehran, IR Iran
| | - Farzin Roohvand
- Department of Virology, Pasteur Institute of Iran, Tehran, IR Iran
- Corresponding Authors: Parastoo Ehsani, Department of Molecular Biology, Pasteur Institute of Iran, Tehran, IR Iran. Tel/Fax.: +98 21 6411-2167, E-mail: . Farzin Roohvand, Department of Virology, Pasteur Institute of Iran, Tehran, IR Iran. Tel/Fax: +98-2166496682, E-mail:
| | - Arash Memarnejadian
- Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, IR Iran
| | - Ali Hatef Salmanian
- Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, IR Iran
| | - Soheila Ajdary
- Department of Immunology, Pasteur Institute of Iran, Tehran, IR Iran
| | - Parastoo Ehsani
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, IR Iran
- Corresponding Authors: Parastoo Ehsani, Department of Molecular Biology, Pasteur Institute of Iran, Tehran, IR Iran. Tel/Fax.: +98 21 6411-2167, E-mail: . Farzin Roohvand, Department of Virology, Pasteur Institute of Iran, Tehran, IR Iran. Tel/Fax: +98-2166496682, E-mail:
| |
Collapse
|
44
|
Schneider JD, Marillonnet S, Castilho A, Gruber C, Werner S, Mach L, Klimyuk V, Mor TS, Steinkellner H. Oligomerization status influences subcellular deposition and glycosylation of recombinant butyrylcholinesterase in Nicotiana benthamiana. PLANT BIOTECHNOLOGY JOURNAL 2014; 12:832-9. [PMID: 24618259 PMCID: PMC4265266 DOI: 10.1111/pbi.12184] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 12/15/2013] [Indexed: 05/20/2023]
Abstract
Plants have a proven track record for the expression of biopharmaceutically interesting proteins. Importantly, plants and mammals share a highly conserved secretory pathway that allows similar folding, assembly and posttranslational modifications of proteins. Human butyrylcholinesterase (BChE) is a highly sialylated, tetrameric serum protein, investigated as a bioscavenger for organophosphorous nerve agents. Expression of recombinant BChE (rBChE) in Nicotiana benthamiana results in accumulation of both monomers as well as assembled oligomers. In particular, we show here that co-expression of BChE with a novel gene-stacking vector, carrying six mammalian genes necessary for in planta protein sialylation, resulted in the generation of rBChE decorated with sialylated N-glycans. The N-glycosylation profile of monomeric rBChE secreted to the apoplast largely resembles the plasma-derived orthologue. In contrast, rBChE purified from total soluble protein extracts was decorated with a significant portion of ER-typical oligomannosidic structures. Biochemical analyses and live-cell imaging experiments indicated that impaired N-glycan processing is due to aberrant deposition of rBChE oligomers in the endoplasmic reticulum or endoplasmic-reticulum-derived compartments. In summary, we show the assembly of rBChE multimers, however, also points to the need for in-depth studies to explain the unexpected subcellular targeting of oligomeric BChE in plants.
Collapse
Affiliation(s)
- Jeannine D Schneider
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life SciencesVienna, Austria
| | | | - Alexandra Castilho
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life SciencesVienna, Austria
| | - Clemens Gruber
- Department of Chemistry, University of Natural Resources and Life SciencesVienna, Austria
| | | | - Lukas Mach
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life SciencesVienna, Austria
| | | | - Tsafrir S Mor
- The Biodesign Institute, Arizona State UniversityTempe, Arizona, USA
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life SciencesVienna, Austria
| |
Collapse
|
45
|
Mathieu-Rivet E, Kiefer-Meyer MC, Vanier G, Ovide C, Burel C, Lerouge P, Bardor M. Protein N-glycosylation in eukaryotic microalgae and its impact on the production of nuclear expressed biopharmaceuticals. FRONTIERS IN PLANT SCIENCE 2014; 5:359. [PMID: 25183966 PMCID: PMC4135232 DOI: 10.3389/fpls.2014.00359] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/04/2014] [Indexed: 05/09/2023]
Abstract
Microalgae are currently used for the production of food compounds. Recently, few microalgae species have been investigated as potential biofactories for the production of biopharmaceuticals. Indeed in this context, microalgae are cheap, classified as Generally Recognized As Safe (GRAS) organisms and can be grown easily. However, problems remain to be solved before any industrial production of microalgae-made biopharmaceuticals. Among them, post-translational modifications of the proteins need to be considered. Especially, N-glycosylation acquired by the secreted recombinant proteins is of major concern since most of the biopharmaceuticals are N-glycosylated and it is well recognized that glycosylation represent one of their critical quality attribute. Therefore, the evaluation of microalgae as alternative cell factory for biopharmaceutical productions thus requires to investigate their N-glycosylation capability in order to determine to what extend it differs from their human counterpart and to determine appropriate strategies for remodeling the microalgae glycosylation into human-compatible oligosaccharides. Here, we review the secreted recombinant proteins which have been successfully produced in microalgae. We also report on recent bioinformatics and biochemical data concerning the structure of glycans N-linked to proteins from various microalgae phyla and comment the consequences on the glycan engineering strategies that may be necessary to render those microalgae-made biopharmaceuticals compatible with human therapy.
Collapse
Affiliation(s)
- Elodie Mathieu-Rivet
- Laboratoire Glyco-MEV, Faculté des Sciences et Techniques, UPRES EA 4358, Normandie Université, IRIB, VASIMont-Saint-Aignan, France
| | - Marie-Christine Kiefer-Meyer
- Laboratoire Glyco-MEV, Faculté des Sciences et Techniques, UPRES EA 4358, Normandie Université, IRIB, VASIMont-Saint-Aignan, France
| | - Gaëtan Vanier
- Laboratoire Glyco-MEV, Faculté des Sciences et Techniques, UPRES EA 4358, Normandie Université, IRIB, VASIMont-Saint-Aignan, France
| | - Clément Ovide
- Laboratoire Glyco-MEV, Faculté des Sciences et Techniques, UPRES EA 4358, Normandie Université, IRIB, VASIMont-Saint-Aignan, France
| | - Carole Burel
- Laboratoire Glyco-MEV, Faculté des Sciences et Techniques, UPRES EA 4358, Normandie Université, IRIB, VASIMont-Saint-Aignan, France
| | - Patrice Lerouge
- Laboratoire Glyco-MEV, Faculté des Sciences et Techniques, UPRES EA 4358, Normandie Université, IRIB, VASIMont-Saint-Aignan, France
| | - Muriel Bardor
- Laboratoire Glyco-MEV, Faculté des Sciences et Techniques, UPRES EA 4358, Normandie Université, IRIB, VASIMont-Saint-Aignan, France
- Institut Universitaire de FranceParis, France
| |
Collapse
|
46
|
Recombinant plant-derived pharmaceutical proteins: current technical and economic bottlenecks. Biotechnol Lett 2014; 36:2367-79. [DOI: 10.1007/s10529-014-1621-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/09/2014] [Indexed: 10/25/2022]
|
47
|
Strasser R, Altmann F, Steinkellner H. Controlled glycosylation of plant-produced recombinant proteins. Curr Opin Biotechnol 2014; 30:95-100. [PMID: 25000187 DOI: 10.1016/j.copbio.2014.06.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 06/11/2014] [Accepted: 06/11/2014] [Indexed: 01/01/2023]
Abstract
Despite their recognized importance for therapeutic proteins, the production of structurally defined glycans is still a challenging issue. However, an increased understanding of glycosylation pathways, recent advances in analytical tools, and emerging technologies for subcellular targeting using chimeric glycosyltransferases are facilitating the rational design of new glycan biosynthetic pathways. Plants are particularly amenable to glyco-engineering approaches and thus they are increasingly being used for the production of recombinant proteins. Here we summarize the main achievements in the field of in planta glyco-engineering for the production of therapeutically relevant proteins.
Collapse
Affiliation(s)
- Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna, Austria
| | - Friedrich Altmann
- Department of Chemistry, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna, Austria
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Muthgasse 18, A-1190 Vienna, Austria.
| |
Collapse
|
48
|
Teh AY, Maresch D, Klein K, Ma JK. Characterization of VRC01, a potent and broadly neutralizing anti-HIV mAb, produced in transiently and stably transformed tobacco. PLANT BIOTECHNOLOGY JOURNAL 2014; 12:300-11. [PMID: 24256218 PMCID: PMC4112721 DOI: 10.1111/pbi.12137] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 09/19/2013] [Accepted: 09/29/2013] [Indexed: 05/07/2023]
Abstract
The proposed clinical trial in Africa of VRC01, a potent broadly neutralizing antibody (bNAb) capable of neutralizing 91% of known HIV-1 isolates, raises concerns about testing a treatment which will be too expensive to be accessible by the most important target population, the poor in under-developed regions such as sub-Saharan Africa. Here, we report the expression of VRC01 in plants as an economic alternative to conventional mammalian-cell-based production platforms. The heavy and light chain genes of VRC01 were cloned onto a single vector, pTRAk.2, which was transformed into Nicotiana benthamiana or Nicotiana tabacum using transient and stable expression production systems respectively. VRC01 has been successfully expressed transiently in plants with expression level of approximately 80 mg antibody/kg; stable transgenic lines expressing up to 100 mg antibody/kg were also obtained. Plant-produced VRC01 from both systems showed a largely homogeneous N-glycosylation profile with a single dominant glycoform. The binding kinetics to gp120 IIIB (approximately 1 nM), neutralization of HIV-1 BaL or a panel of 10 VRC01-sensitive HIV-1 Env pseudoviruses of VRC01 produced in transient and stable plants were also consistent with VRC01 from HEK cells.
Collapse
Affiliation(s)
- Audrey Y‐H. Teh
- Molecular Immunology UnitInfection and Immunity Research CentreSt. George's University of LondonLondonUK
| | - Daniel Maresch
- Department of ChemistryUniversity of Natural Resources and Applied Life SciencesViennaAustria
| | - Katja Klein
- Department of Infectious DiseasesDivision of MedicineImperial College LondonLondonUK
| | - Julian K‐C. Ma
- Molecular Immunology UnitInfection and Immunity Research CentreSt. George's University of LondonLondonUK
| |
Collapse
|
49
|
Schneider JD, Castilho A, Neumann L, Altmann F, Loos A, Kannan L, Mor TS, Steinkellner H. Expression of human butyrylcholinesterase with an engineered glycosylation profile resembling the plasma-derived orthologue. Biotechnol J 2014; 9:501-10. [PMID: 24130173 PMCID: PMC3975692 DOI: 10.1002/biot.201300229] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 09/26/2013] [Accepted: 10/14/2013] [Indexed: 11/07/2022]
Abstract
Human butyrylcholinesterase (BChE) is considered a candidate bioscavenger of nerve agents for use in pre- and post-exposure treatment. However, the presence and functional necessity of complex N-glycans (i.e. sialylated structures) is a challenging issue in respect to its recombinant expression. Here we transiently co-expressed BChE cDNA in the model plant Nicotiana benthamiana with vectors carrying the genes necessary for in planta protein sialylation. Site-specific sugar profiling of secreted recombinant BChE (rBChE) collected from the intercellular fluid revealed the presence of mono- and di-sialylated N-glycans, which largely resembles to the plasma-derived orthologue. Attempts to increase that sialylation content of rBChE by the over-expression of an additional glycosylation enzyme that generates branched N-glycans (i.e. β1,4-N-acetylglucosaminyl-transferase IV), allowed the production of rBChE decorated with tri-sialylated structures (up to 70%). Sialylated and non-sialylated plant-derived rBChE exhibited functional in vitro activity comparable to that of its commercially available equine-derived counterpart. These results demonstrate the ability of plants to generate valuable proteins with designed sialylated glycosylation profiles optimized for therapeutic efficacy. Moreover, the efficient synthesis of carbohydrates present only in minute amounts on the native protein (tri-sialylated N-glycans) facilitates the generation of a product with superior efficacies and/or new therapeutic functions.
Collapse
Affiliation(s)
- Jeannine D. Schneider
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Alexandra Castilho
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Laura Neumann
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Friedrich Altmann
- Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Andreas Loos
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Latha Kannan
- The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Tsafrir S. Mor
- The Biodesign Institute, Arizona State University, Tempe, Arizona, USA
| | - Herta Steinkellner
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| |
Collapse
|
50
|
Loos A, Steinkellner H. Plant glyco-biotechnology on the way to synthetic biology. FRONTIERS IN PLANT SCIENCE 2014; 5:523. [PMID: 25339965 PMCID: PMC4189330 DOI: 10.3389/fpls.2014.00523] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/16/2014] [Indexed: 05/04/2023]
Abstract
Plants are increasingly being used for the production of recombinant proteins. One reason is that plants are highly amenable to glycan engineering processes and allow the production of therapeutic proteins with increased efficacies due to optimized glycosylation profiles. Removal and insertion of glycosylation reactions by knock-out/knock-down approaches and introduction of glycosylation enzymes have paved the way for the humanization of the plant glycosylation pathway. The insertion of heterologous enzymes at exactly the right stage of the existing glycosylation pathway has turned out to be of utmost importance. To enable such precise targeting chimeric enzymes have been constructed. In this short review we will exemplify the importance of correct targeting of glycosyltransferases, we will give an overview of the targeting mechanism of glycosyltransferases, describe chimeric enzymes used in plant N-glycosylation engineering and illustrate how plant glycoengineering builds on the tools offered by synthetic biology to construct such chimeric enzymes.
Collapse
Affiliation(s)
| | - Herta Steinkellner
- *Correspondence: Herta Steinkellner, Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria e-mail:
| |
Collapse
|