Abstract
Gag polyprotein from HIV-1 is able to generate virus-like particles (VLPs) when recombinantly expressed in animal cell platforms. HIV-1 VLP production in HEK293 cells can be improved by the use of different strategies for increasing product titers. One of them is the so-called extended gene expression (EGE), based on repeated medium exchanges and retransfections of the cell culture to prolong the production phase. Another approach is the media supplementation with gene expression enhancers such as valproic acid and caffeine, despite their detrimental effect on cell viability. Valproic acid is a histone deacetylase inhibitor while caffeine has a phosphodiesterase inhibition effect. Here, the combination of the EGE protocol with additive supplementation to maximize VLP production is first tested. As an alternative to the direct additive supplementation, the replacement of these chemical additives by iRNA for obtaining the same inhibition action is also tested. The combination of the EGE protocol with caffeine and valproic acid supplementation resulted in a 1.5-fold improvement in HIV-1 VLP production compared with the EGE protocol alone, representing an overall 18-fold improvement over conventional batch cultivation. shRNAs encoded in the expression vector were tested to substitute valproic acid and caffeine. This novel strategy enhanced VLP production by 2.3 fold without any detrimental effect on cell viability (91.7%) compared with the batch cultivation (92.0%). Finally, the combination of shRNA with EGE resulted in more than 15.6-fold improvement compared with the batch standard protocol traditionally used. The methodology developed enables the production of high titers of HIV-1 VLPs avoiding the toxic effects of additives.
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References
Backliwal G, Hildinger M, Chenuet S, DeJesus M, Wurm FM (2008a) Coexpression of acidic fibroblast growth factor enhances specific productivity and antibody titers in transiently transfected HEK293 cells. New Biotechnol 25:162–166
Backliwal G, Hildinger M, Chenuet S, Wulhfard S, De Jesus M, Wurm FM (2008b) Rational vector design and multi-pathway modulation of HEK 293E cells yield recombinant antibody titers exceeding 1 g/l by transient transfection under serum-free conditions. Nucleic Acids Res 36(15):e96
Backliwal G, Hildinger M, Kuettel I, Delegrange F, Hacker DL, Wurm FM (2008c) Valproic acid: a viable alternative to sodium butyrate for enhancing protein expression in mammalian cell cultures. Biotechnol Bioeng 101:182–189
Baldi L, Hacker DL, Adam M, Wurm FM (2007) Recombinant protein production by large-scale transient gene expression in mammalian cells: state of the art and future perspectives. Biotechnol Lett 29:677–684
Cervera L, Gutiérrez-Granados S, Martínez M, Blanco J, Gòdia F, Segura MM (2013) Generation of HIV-1 Gag VLPs by transient transfection of HEK 293 suspension cell cultures using an optimized animal-derived component free medium. J Biotechnol 166:152–165
Cervera L, Fuenmayor J, González-Domínguez I, Gutiérrez-Granados S, Segura MM, Gòdia F (2015a) Selection and optimization of transfection enhancer additives for increased virus-like particle production in HEK293 suspension cell cultures. Appl Microbiol Biotechnol 99:9935–9949
Cervera L, Gutiérrez-Granados S, Berrow NS, Segura MM, Gòdia F (2015b) Extended gene expression by medium exchange and repeated transient transfection for recombinant protein production enhancement. Biotechnol Bioeng 112:934–946
Choi OH, Shamim MT, Daly JW, Padgett L (1988) Caffeine and theophylline analogues: correlation of behavioral effects with activity as adenosine receptor antagonists and as phosphodiesterase inhibitors. Life Sci 43:387–398
Ellis BL, Potts PR, Porteus MH (2011) Creating higher titer lentivirus with caffeine. Hum Gene Ther 22:93–100
Fischer S, Paul AJ, Wagner A, Mathias S (2015) miR-2861 as novel HDAC5 inhibitor in CHO cells enhances productivity while maintaining product quality. Biotechnol Bioeng 112:2142–2153
Fuenmayor J, Cervera L, Gutiérrez-Granados S, Godia F (2017a) Transient gene expression optimization and expression vector comparison to improve HIV-1 VLP production in HEK293 cell lines. Appl Microbiol Biotechnol 102:165–174
Fuenmayor J, Gòdia F, Cervera L (2017b) Production of virus-like particles for vaccines. New Biotechnol 39:174–180
Gutiérrez-Granados S, Cervera L, Gòdia F, Carrillo J, Segura MM (2013) Development and validation of a quantitation assay for fluorescently tagged HIV-1 virus-like particles. J Virol Methods 193:85–95
Hermida-Matsumoto L, Resh MD (2000) Localization of human immunodeficiency virus type 1 Gag and Env at the plasma membrane by confocal imaging. J Virol 74:8670–8679
Khochbin S, Verdel A, Lemercier C, Seigneurin-Berny D (2001) Functional significance of histone deacetylase diversity. Curr Opin Genet Dev 11:162–166
Liu C, Dalby B, Chen W, Kilzer JM, Chiou HC (2008) Transient transfection factors for high-level recombinant protein production in suspension cultured mammalian cells. Mol Biotechnol 39:141–153
Lowe SW (2014) Stable RNA interference rules for silencing. Nat Cell Biol 16:10–18
Middleton T, Sugden B (1994) Retention of plasmid DNA in mammalian cells is enhanced by binding of the Epstein-Barr virus replication protein EBNA1. J Virol 68:4067–4071
Roldao A, Mellado MC, Castilho LR, Carrondo MJ, Alves PM (2010) Virus-like particles in vaccine development. Expert Rev Vaccines 9:1149–1176
Roy S, Packman K, Jeffrey R, Tenniswood M (2005) Histone deacetylase inhibitors differentially stabilize acetylated p53 and induce cell cycle arrest or apoptosis in prostate cancer cells. Cell Death Differ 12:482–491
Schiestl RH, Gietz RD (1989) High efficiency transformation of intact yeast cells using single-stranded nucleic acids as carrier. Curr Genet 16:339–346
Suzuki E, Ollis DF (1990) Enhanced antibody production at slowed growth rates: experimental demonstration and a simple structured model. Biotechnol Prog 6:231–236
Tait AS, Brown CJ, Galbraith DJ, Hines MJ, Hoare M, Birch JR, James DC (2004) Transient production of recombinant proteins by Chinese hamster ovary cells using polyethyleneimine/DNA complexes in combination with microtubule disrupting anti-mitotic agents. Biotechnol Bioeng 88:707–721
Wade-Martins R, Frampton J, James MR (1999) Long-term stability of large insert genomic DNA episomal shuttle vectors in human cells. Nucleic Acids Res 27:1674–1682
Ye J, Kober V, Tellers M, Naji Z, Salmon P, Markusen JF (2009) High-level protein expression in scalable CHO transient transfection. Biotechnol Bioeng 103:542–551
Zhu J (2012) Mammalian cell protein expression for biopharmaceutical production. Biotechnol Adv 30:1158–1170
Acknowledgements
The authors wish to thank Dr. Amine Kamen (McGill University, Montreal, Canada) for providing theHEK293SF-3F6 used in this work. We would also like to thank Dr. Julià Blanco at IRSI Caixa (Badalona, Spain) for providing the plasmid construct for Gag-GFP. The contribution of Manuela Costa (Institut de Biotecnologia i Biomedicina, UAB) to the FACS analysis is deeply appreciated. The support of Dr. Salvador Bartolomé (Department de Bioquímica i de Biologia Molecular, UAB) in fluorimetry analysis is recognized.
Funding
This study is supported by a grant of SEIDI – Ministerio de Economía y Competitividad of SPAIN (BIO2012-31251).
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This article does not contain any studies with human participants or animals performed by any of the authors.
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Fuenmayor, J., Cervera, L., Rigau, C. et al. Enhancement of HIV-1 VLP production using gene inhibition strategies. Appl Microbiol Biotechnol 102, 4477–4487 (2018). https://doi.org/10.1007/s00253-018-8930-8
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DOI: https://doi.org/10.1007/s00253-018-8930-8