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Destro F, Joseph J, Srinivasan P, Kanter JM, Neufeld C, Wolfrum JM, Barone PW, Springs SL, Sinskey AJ, Cecchini S, Kotin RM, Braatz RD. Mechanistic modeling explains the production dynamics of recombinant adeno-associated virus with the baculovirus expression vector system. Mol Ther Methods Clin Dev 2023; 30:122-146. [PMID: 37746245 PMCID: PMC10512016 DOI: 10.1016/j.omtm.2023.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 05/30/2023] [Indexed: 09/26/2023]
Abstract
Current manufacturing processes for recombinant adeno-associated viruses (rAAVs) have less-than-desired yields and produce significant amounts of empty capsids. The increasing demand and the high cost of goods for rAAV-based gene therapies motivate development of more efficient manufacturing processes. Recently, the US Food and Drug Administration (FDA) approved the first rAAV-based gene therapy product manufactured in the baculovirus expression vector system (BEVS), a technology that demonstrated production of high titers of full capsids. This work presents a first mechanistic model describing the key extracellular and intracellular phenomena occurring during baculovirus infection and rAAV maturation in the BEVS. The model predictions are successfully validated for in-house and literature experimental measurements of the vector genome and of structural and non-structural proteins collected during rAAV manufacturing in the BEVS with the TwoBac and ThreeBac constructs. A model-based analysis of the process is carried out to identify the bottlenecks that limit full capsid formation. Vector genome amplification is found to be the limiting step for rAAV production in Sf9 cells using either the TwoBac or ThreeBac system. In turn, vector genome amplification is hindered by limiting Rep78 levels. Transgene and non-essential baculovirus protein expression in the insect cell during rAAV manufacturing also negatively influences the rAAV production yields.
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Affiliation(s)
- Francesco Destro
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - John Joseph
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Prasanna Srinivasan
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Joshua M. Kanter
- Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Caleb Neufeld
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jacqueline M. Wolfrum
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Paul W. Barone
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Stacy L. Springs
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anthony J. Sinskey
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sylvain Cecchini
- Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Robert M. Kotin
- Gene Therapy Center, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
- Carbon Biosciences, Waltham, MA 02451, USA
| | - Richard D. Braatz
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Center for Biomedical Innovation, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Hashemzadeh MS, Gharari N. Biosynthesis of a VLP-type nanocarrier specific to cancer cells using the BEVS expression system for targeted drug delivery. J Genet Eng Biotechnol 2023; 21:20. [PMID: 36795253 PMCID: PMC9932404 DOI: 10.1186/s43141-023-00479-9] [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: 01/03/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023]
Abstract
OBJECTIVE Canine parvovirus (CPV) is a small virus without an envelope that consists of three viral proteins including VP1, VP2, and VP3. Exclusively, the VP2 can form a typically CPV-sized virus-like particle (CPV-VLP) that can be used as a biological nanocarrier for diagnostic and therapeutic purposes since these VLPs can target cancer cells specially through the transferrin surface receptors (TFRs). Consequently, we aimed to produce these nanocarriers to be used for specific targeting of cancer cells. METHODS Sf9 insect cells were transfected with constructed recombinant bacmid shuttle vector encoding an enhanced green fluorescent protein (EGFP) and CPV-VP2 by the cationic lipids of Cellfectin II. Subsequently, two recombinant baculoviruses expressing EGFP and VP2 were produced and expression of VP2 was increased under the optimal condition. In consequence, the CPV-VLP nanoparticles composed of recombinant VP2 subunits were extracted. The purity of VLPs was then evaluated by SDS-PAGE, and the structural integrity and quality of the final product were evaluated by TEM and HA methods. Eventually, the size distribution of the produced biological nanoparticles and their uniformity were determined by the DLS method. RESULTS The expression of EGFP protein was confirmed by fluorescent microscopy, and the expression of VP2 protein was evaluated by SDS-PAGE and western blotting. Infected Sf9 insect cells also showed cytopathic effects (CPEs), and the maximum expression of VP2 occurred at MOI of 10 (pfu/cell) at the harvest time of 72 h post-infection (hpi). After performing various stages of purification, buffer exchange, and concentration, the quality and structural integrity of the VLP product were confirmed. The results of the DLS technique showed the presence of uniform particles (PdI below 0.5) with an approximate size of 25 nm. CONCLUSION The results indicate BEVS as an appropriate and efficient system for generating CPV-VLPs, and the used method based on two-stage ultracentrifugation was appropriate for purifying these nanoparticles. Produced nanoparticles can be used as the biologic nano-carriers in future studies.
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Affiliation(s)
| | - Nariman Gharari
- grid.7605.40000 0001 2336 6580Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
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Bui-Marinos MP, Todd LA, Wasson MCD, Morningstar BEE, Katzenback BA. Prior induction of cellular antiviral pathways limits frog virus 3 replication in two permissive Xenopus laevis skin epithelial-like cell lines. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 124:104200. [PMID: 34237380 DOI: 10.1016/j.dci.2021.104200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/03/2021] [Accepted: 07/03/2021] [Indexed: 06/13/2023]
Abstract
Frog virus 3 (FV3) causes mortality in a range of amphibian species. Despite the importance of the skin epithelium as a first line of defence against FV3, the interaction between amphibian skin epithelial cells and FV3 remains largely uncharacterized. Here, we used newly established Xenopus laevis skin epithelial-like cell lines, Xela DS2 and Xela VS2, to study the susceptibility and permissiveness of frog skin epithelial cells to FV3, and the innate immune antiviral and proinflammatory gene regulatory responses of these cells to FV3. Both cell lines are susceptible and permissive to FV3, yet do not exhibit appreciable transcript levels of scavenger receptors thought to be used by FV3 for cellular entry. Xela DS2 and Xela VS2 upregulate antiviral and proinflammatory cytokine transcripts in response to poly(I:C) but not to FV3 or UV-inactivated FV3. Poly(I:C) pretreatment limits FV3 replication and FV3-induced cytopathic effects in both cell lines. Thus, Xela DS2 and Xela VS2 can support FV3 replication, represent in vitro systems to investigate antiviral responses of frog skin epithelial cells, and can serve as novel tools for screening compounds that initiate effective antiviral programs to limit FV3 replication.
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Affiliation(s)
| | - Lauren A Todd
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | | | | | - Barbara A Katzenback
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
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Ng SW, Selvarajah GT, Cheah YK, Mustaffa Kamal F, Omar AR. Cellular Metabolic Profiling of CrFK Cells Infected with Feline Infectious Peritonitis Virus Using Phenotype Microarrays. Pathogens 2020; 9:pathogens9050412. [PMID: 32466289 PMCID: PMC7281222 DOI: 10.3390/pathogens9050412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/13/2020] [Accepted: 05/18/2020] [Indexed: 02/07/2023] Open
Abstract
Feline infectious peritonitis (FIP) is a fatal feline immune-mediated disease caused by feline infectious peritonitis virus (FIPV). Little is known about the biological pathways associated in FIP pathogenesis. This is the first study aiming to determine the phenotypic characteristics on the cellular level in relation to specific metabolic pathways of importance to FIP pathogenesis. METHODS The internalization of type II FIPV WSU 79-1146 in Crandell-Rees Feline Kidney (CrFK) cells was visualized using a fluorescence microscope, and optimization prior to phenotype microarray (PM) study was performed. Then, four types of Biolog Phenotype MicroArray™ plates (PM-M1 to PM-M4) precoated with different carbon and nitrogen sources were used to determine the metabolic profiles in FIPV-infected cells. RESULTS The utilization of palatinose was significantly low in FIPV-infected cells; however, there were significant increases in utilizing melibionic acid, L-glutamine, L-glutamic acid and alanyl-glutamine (Ala-Gln) compared to non-infected cells. CONCLUSION This study has provided the first insights into the metabolic profiling of a feline coronavirus infection in vitro using PMs and deduced that glutamine metabolism is one of the essential metabolic pathways for FIPV infection and replication. Further studies are necessary to develop strategies to target the glutamine metabolic pathway in FIPV infection.
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Affiliation(s)
- Shing Wei Ng
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia;
- Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia
| | - Gayathri Thevi Selvarajah
- Department of Veterinary Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia;
- Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia
- Correspondence:
| | - Yoke Kqueen Cheah
- Department of Biomedical Sciences, Faculty of Medicine and Biomedical Health Sciences, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia;
| | - Farina Mustaffa Kamal
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia; (F.M.K.); (A.R.O.)
| | - Abdul Rahman Omar
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia; (F.M.K.); (A.R.O.)
- Institute of Bioscience, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia
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RNA interference technology to improve the baculovirus-insect cell expression system. Biotechnol Adv 2018; 36:443-451. [DOI: 10.1016/j.biotechadv.2018.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/11/2017] [Accepted: 01/13/2018] [Indexed: 02/02/2023]
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Matindoost L, Nielsen LK, Reid S. Intracellular Trafficking of Baculovirus Particles: A Quantitative Study of the HearNPV/HzAM1 Cell and AcMNPV/Sf9 Cell Systems. Viruses 2015; 7:2288-307. [PMID: 25951488 PMCID: PMC4452906 DOI: 10.3390/v7052288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/21/2015] [Accepted: 04/28/2015] [Indexed: 01/29/2023] Open
Abstract
To replace the in vivo production of baculovirus-based biopesticides with a more convenient in vitro produced product, the limitations imposed by in vitro production have to be solved. One of the main problems is the low titer of HearNPV budded virions (BV) in vitro as the use of low BV titer stocks can result in non-homogenous infections resulting in multiple virus replication cycles during scale up that leads to low Occlusion Body yields. Here we investigate the baculovirus traffic in subcellular fractions of host cells throughout infection with an emphasis on AcMNPV/Sf9 and HearNPV/HzAM1 systems distinguished as "good" and "bad" BV producers, respectively. qPCR quantification of viral DNA in the nucleus, cytoplasm and extracellular fractions demonstrated that although the HearNPV/HzAM1 system produces twice the amount of vDNA as the AcMNPV/Sf9 system, its percentage of BV to total progeny vDNA was lower. vDNA egress from the nucleus to the cytoplasm is sufficient in both systems, however, a higher percentage of vDNA in the HearNPV/HzAM1 system remain in the cytoplasm and do not bud out of the cells compared to the AcMNPV/Sf9 system. In both systems more than 75% of the vDNA produced in the nuclear fraction go unused, without budding or being encapsulated in OBs showing the capacity for improvements that could result from the engineering of the virus/cell line systems to achieve better productivities for both BV and OB yields.
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Affiliation(s)
- Leila Matindoost
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Lars K Nielsen
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, QLD 4072, Australia.
| | - Steve Reid
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, QLD 4072, Australia.
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Matindoost L, Hu H, Chan LCL, Nielsen LK, Reid S. The effect of cell line, phylogenetics and medium on baculovirus budded virus yield and quality. Arch Virol 2013; 159:91-102. [DOI: 10.1007/s00705-013-1789-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 06/04/2013] [Indexed: 12/18/2022]
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Adaptation of the Spodoptera exigua Se301 insect cell line to grow in serum-free suspended culture. Comparison of SeMNPV productivity in serum-free and serum-containing media. Appl Microbiol Biotechnol 2012. [DOI: 10.1007/s00253-012-4576-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Palomares LA, Mena JA, Ramírez OT. Simultaneous expression of recombinant proteins in the insect cell-baculovirus system: production of virus-like particles. Methods 2012; 56:389-95. [PMID: 22300754 DOI: 10.1016/j.ymeth.2012.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 01/16/2012] [Accepted: 01/17/2012] [Indexed: 12/11/2022] Open
Abstract
The insect cell-baculovirus system (IC-BEVS) is widely used for the production of recombinant viral proteins for vaccine applications. It is especially suitable for the production of virus-like particles, which often require the simultaneous production of several recombinant proteins. Here, the available tools and process requirements for the simultaneous production of several recombinant proteins using the IC-BEVS are discussed. The production of double-layered rotavirus like particles is used as a specific example for the simultaneous production of two recombinant proteins. Methods to quantify VLP in small samples are described. The multiplicity and time of infection are presented as tools to manipulate protein concentration, and the effect on protein concentration ratios on the assembly efficiency of double-layered rotavirus like particles is discussed. It was found that not only the ratio between the recombinant proteins is determinant of VLP assembly efficiency, but also that assembly efficiency is related to the characteristics of the assembled proteins. This is the first time that kinetics of VLP production are followed during cultures, and that the assembly efficiency is quantitatively determined.
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Affiliation(s)
- Laura A Palomares
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, Morelos, CP 62250, Mexico.
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Weber W, Weber E, Geisse S, Memmert K. Optimisation of protein expression and establishment of the Wave Bioreactor for Baculovirus/insect cell culture. Cytotechnology 2011; 38:77-85. [PMID: 19003089 DOI: 10.1023/a:1021102015070] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As the interest of research is beginning to shift from genomicsto proteomics the number of proteins to be expressed is rapidlyincreasing. To do so, well-established, high-level expressionsystems and rapid, cost-effective production means are needed. For addressing the latter, a novel cultivation system for recombinant cells, the Wave Bioreactortrade mark has recently becomeavailable. We describe the set-up and the optimisation of parameters essential for successful operation and growth of insect cells to high cell densities in the Wave Bioreactor. According to our experience, the Cellbagtrade mark system comparesvery favorably to conventional cultivation vessels such as bioreactors and roller cultures with respect to simplicity ofoperation and cost. Additionally, we developed a rapid and simple protocol for assessing expression and production conditions for the Baculovirus/insect cell system applicable to many different genes/proteins. Important parameters like MOI,TOI, peak cell density (PCD) and expression levels are determinedin pre-experiments on small scale to achieve optimal expressionof a given protein. These conditions are subsequently transformedand applied to large scale cultures grown in nutrient-supplemented medium in the Wave Bioreactor.
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Affiliation(s)
- Wilfried Weber
- Core Technologies/Biomolecules Production, Novartis Pharma AG, Research, Building WSJ-506.101, CH-4002, Basel, Switzerland
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Gotoh T, Fukuhara M, Kikuchi KI. Mathematical model for change in diameter distribution of baculovirus-infected Sf-9 insect cells. Biochem Eng J 2008. [DOI: 10.1016/j.bej.2008.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Harwood S. Small-scale protein production with the baculovirus expression vector system. Methods Mol Biol 2007; 388:211-24. [PMID: 17951772 DOI: 10.1007/978-1-59745-457-5_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Improved methods of baculovirus cloning and insect cell culture and their commercialization have made the use of the baculovirus expression vector system (BEVS) a routine tool for the production of preparative quantities of recombinant protein. This chapter outlines basic techniques for small-scale protein production using the BEVS, including protocols for expression from adherent and suspension insect cell cultures, titer estimation, and expression optimization.
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Affiliation(s)
- Steve Harwood
- Molecular Probes Invitrogen Detection Technologies, Eugene, OR, USA
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13
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Population kinetics during simultaneous infection of insect cells with two different recombinant baculoviruses for the production of rotavirus-like particles. BMC Biotechnol 2007; 7:39. [PMID: 17610729 PMCID: PMC1929069 DOI: 10.1186/1472-6750-7-39] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 07/04/2007] [Indexed: 11/15/2022] Open
Abstract
Background The simultaneous production of various recombinant proteins in every cell of a culture is often needed for the production of virus-like particles (VLP) or vectors for gene therapy. A common approach for such a purpose is the coinfection of insect cell cultures with different recombinant baculoviruses, each containing one or more recombinant genes. However, scarce information exists regarding kinetics during multiple infections, and to our knowledge, no studies are available on the behavior of the different populations that arise during coinfections. Such information is useful for designing infection strategies that maximize VLP or vector yield. In this work, kinetics of cell populations expressing rotavirus GFPVP2 (infected with bacGFPVP2), VP6 (infected with bacVP6), or both proteins simultaneously (coinfected with both baculoviruses) were followed by flow cytometry. Results In single infections, the population infected with any of the recombinant baculoviruses followed the Poisson distribution, as the population expressing a recombinant protein exhibited a hyperbolic-type function with respect to the multiplicity of infection (MOI) up to 5 pfu/cell. In coinfections, the population fraction expressing each recombinant protein could not be anticipated from results of single infections, as in some cases interference and synergistic effects were found. Only cultures with a total MOI below 5 pfu/cell followed the Poisson distribution. For cultures with a MOI of bacGFPVP2 above that of bacVP6 (overall MOI above 5 pfu/cell), the total population expressing one or both recombinant proteins was as low as 50% below that predicted by Poisson. In contrast, the population fraction expressing VP6 increased in coinfections, compared to that in single infections. The largest population fraction simultaneously expressing both recombinant proteins was 58%, and corresponded to cultures infected at a MOI of 5 and 1 pfu/cell of bacGFPVP2 and bacVP6, respectively. Conclusion The infection conditions that maximize the cell population simultaneously expressing two recombinant proteins were determined. Such conditions could not have been anticipated from population kinetics in individual infections. This information should be taken into account for improved simultaneous production of various recombinant proteins in any work dealing with coinfections.
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Aucoin MG, Perrier M, Kamen AA. Improving AAV vector yield in insect cells by modulating the temperature after infection. Biotechnol Bioeng 2007; 97:1501-9. [PMID: 17274066 DOI: 10.1002/bit.21364] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Vectors based on adeno-associated viruses (AAV) are sought for therapeutic gene delivery because of their ability to transduce a variety of tissues with no significant immunological response. Production using the baculovirus expression vector (BEV)/insect cell system has the potential to meet the needs for pre-clinical and clinical trials. In this co-infection system, three baculoviruses are used to produce the AAV vector. A strategy aimed at increasing encapsidation/maturation of the viral vector involved varying the temperature over the course of the process. Cultures were subjected to temperature changes at various times pre- and post-infection (up to 24 h post-infection). It was found that raising the culture temperature to 30 degrees C at the time of infection nearly tripled the infectious titer. In fact, increasing the temperature to 30 degrees C at any time in the process investigated resulted in an increase in titer. Also, raising the culture to 33 degrees C or lowering the temperature to 24 degrees or 21 degrees C resulted in lower titers. The rise in infectious titer was also confirmed by an increase in DNase resistant particles (DRPs). Varying the temperature, however, did not affect the total amount of capsids significantly. Therefore increasing the culture temperature resulted in better encapsidation as determined by the ratio of capsids to DRPs to infectious particles. It is believed that an increase in early proteins and possibly a quicker cascade of baculovirus infection events resulted in this increased packaging efficiency.
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Affiliation(s)
- Marc G Aucoin
- Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Ave., Montréal, Quebec, Canada
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15
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Intracellular dynamics in rotavirus-like particles production: Evaluation of multigene and monocistronic infection strategies. Process Biochem 2006. [DOI: 10.1016/j.procbio.2006.06.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Vieira HLA, Estêvão C, Roldão A, Peixoto CC, Sousa MFQ, Cruz PE, Carrondo MJT, Alves PM. Triple layered rotavirus VLP production: Kinetics of vector replication, mRNA stability and recombinant protein production. J Biotechnol 2005; 120:72-82. [PMID: 16023241 DOI: 10.1016/j.jbiotec.2005.03.026] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Revised: 02/25/2005] [Accepted: 03/16/2005] [Indexed: 10/25/2022]
Abstract
Rotavirus infection causes diarrhoeal disease in infants, killing more than half million children each year. Virus-like particles (VLP) seem to be excellent vaccine candidates, since they are cheaper to produce than attenuated viral vaccines and safer, as they do not contain genetic material. The present work focus on a triple layered particle composed by three rotavirus structural proteins: VP2, VP6 and VP7, produced in an insect cell/baculovirus expressing system. Two strategies were evaluated for 2/6/7 VLP production: co-infection with three monocistronic baculovirus vectors or single-infection with a tricistronic multi-gene baculovirus vector; these strategies were followed at different levels: baculovirus DNA replication kinetics, mRNA stability, protein production and VLP formation. This study highlights some of the reasons why the tricistronic baculovirus strategy is more efficient for production of triple layered rotavirus 2/6/7 VLP than monocistronic co-infection, in particular: (i) the tricistronic vector presents higher DNA replication rates than the monocistronic vectors, (ii) the mRNA stability is invariant for all mRNAs corresponding to VP2, VP6 and VP7 and (iii) the tricistronic baculovirus strategy produces an excess of VP7 over VP6 when compared to the VP7/VP6 stoichiometric ratio in the native rotavirus. Although the co-infection strategy leads to protein production akin to the rotavirus VP7/VP6 stoichiometric ratio, the tricistronic vector strategy yields higher amounts of rotavirus-like particles.
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Affiliation(s)
- Helena L A Vieira
- Instituto de Biologia Experimental e Tecnológica (IBET), Apartado 12, 2781-901 Oeiras, Portugal
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Bleckwenn NA, Bentley WE, Shiloach J. Evaluation of production parameters with the vaccinia virus expression system using microcarrier attached HeLa cells. Biotechnol Prog 2005; 21:554-61. [PMID: 15801798 DOI: 10.1021/bp0498443] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Parameters that affect production of the recombinant reporter protein, EGFP, in the T7 promoter based VOTE vaccinia virus-HeLa cell expression system were examined. Length of infection phase, inducer concentration, and timing of its addition relative to infection were evaluated in 6-well plate monolayer cultures. One hour infection with 1.0 mM IPTG added at the time of infection provided a robust process. For larger scale experiments, anchorage-dependent HeLa cells were grown on 5 g/L Cytodex 3 microcarriers. The change to this dynamic culture environment, with cell-covered microcarriers suspended in culture medium in spinner flasks, suggested a re-examination of the multiplicity of infection (MOI) for this culture type that indicated a need for an increase in the number of virus particles per cell to 5.0, higher than that needed for complete infection in monolayer tissue flask culture. Additionally, dissolved oxygen level and temperature during the protein production phase were evaluated for their effect on EGFP expression in microcarrier spinner flask culture. Both increased dissolved oxygen, based on surface area to volume (SA/V) adjustments, and decreased temperature from 37 to 31 degrees C showed increases in EGFP production over the course of the production phase. The level of production achieved with this system reached approximately 17 microg EGFP/10(6) infected cells.
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Affiliation(s)
- Nicole A Bleckwenn
- Biotechnology Unit, NIDDK, National Institutes of Health, DHHS, 9000 Rockville Pike, Bethesda, Maryland 20892, USA
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Petricevich VL, Mendonça RZ. Inhibitory potential of Crotalus durissus terrificus venom on measles virus growth. Toxicon 2003; 42:143-53. [PMID: 12906885 DOI: 10.1016/s0041-0101(03)00124-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This paper presents the antiviral activity found in a snake with Crotalus durissus terrificus venom (Cdt), studied by use of microplate inhibition assay, using measles virus (MV). Cdt at concentrations below 100 microg/ml showed no cytotoxicity for Vero cells. This study shows the optimal conditions for cell treatment and infection. Two factors that affect virus binding and infection efficiency were studied: the use of an adsorption step, where infection volume was varied; and the concentration of fetal bovine serum (FBS). The adsorption step, with or without FBS, increased the bound virus percentage, whereas it increased bound virus at equilibrium only in FBS-free until 2.5% FBS. In contrast, the addition of 10% FBS decreased the bound virus percentage. The inhibition of MV replication in Vero cells was observed when Cdt was added either before or during cell infection with virus. Its inhibitory concentration against MV replication was 0.1 until 100 microg/ml, respectively. The anti-MV effect of the Cdt was gradually decreased when it was added before or during infection, and little inhibition was observed when Cdt was added 1 h after infection, suggesting that the MV infection was inhibited at the time of the initial events such as at the moment of adsorption and penetration of the viral cycle. In conclusion, Cdt contains anti-MV effects that may be of potential clinical interest.
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Affiliation(s)
- Vera L Petricevich
- Laboratório de Imunoquímica, Instituto Butantan, Av. Vital Brasil n. 1500, CEP 05504-900 São Paulo, Brazil.
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Palomares LA, López S, Ramírez OT. Strategies for manipulating the relative concentration of recombinant rotavirus structural proteins during simultaneous production by insect cells. Biotechnol Bioeng 2002; 78:635-44. [PMID: 11992529 DOI: 10.1002/bit.10243] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Adequate production strategies of virus-like particles are among the challenges that must be addressed before such complex multimeric structures find practical applications as vaccines. Attainment of the correct stoichiometric relation between proteins that constitute virus-like particles should result in an increased productivity by maximizing the concentration of assembled proteins and preventing the accumulation of waste monomers. In this work, strategies for manipulating the relative concentration between two of the structural proteins that constitute rotavirus-like particles (VP2 and VP6) were explored using the insect cell baculovirus expression vector system. It was shown that multiplicity of infection is a useful tool for manipulating protein production rates and maximum concentrations in cultures expressing one or two recombinant proteins. Thus, multiplicity of infection can be employed for improving production of rotavirus-like particles. VP2 and VP6 production rates obtained during individual infections remained unchanged when both were simultaneously produced, indicating that such rates can be utilized for estimating protein concentrations during coexpression. Manipulation of the time of infection between the two recombinant baculoviruses, proposed here for the first time, also proved to be effective for controlling the relative protein concentrations. The use of such sequential infections constituted an effective production alternative that does not require high amounts of virus stocks and is easy to implement. In addition to VP2 and VP6, kinetic parameters for the individual production of the other two proteins (VP4 and VP7) that constitute rotavirus-like particles were also obtained.
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Affiliation(s)
- Laura A Palomares
- Departamento de Bioingeniería, Instituto de Biotecnología, Universidad Nacional Autónoma de México, A.P. 510-3, Cuernavaca Morelos, México.
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