title: Critical phases of viral production processes monitored by capacitance.
abstract: Over the last decade industrial manufacturing of viral vaccines and viral vectors for prophylactic and therapeutic applications is experiencing a remarkable growth. Currently, the quality attributes of viral derived products are assessed only at the end-point of the production process, essentially because in-process monitoring tools are not available or not implemented at industrial scale. However, to demonstrate process reproducibility and robustness, manufacturers are strongly advised by regulatory agencies to adopt more on-line process monitoring and control. Dielectric spectroscopy has been successfully used as an excellent indicator of the cell culture state in mammalian and yeast cell systems. We previously reported the use of this technique for monitoring influenza and lentiviral productions in HEK293 cell cultures. For both viruses, multi-frequency capacitance measurements allowed not only the on-line monitoring of the production kinetics, but also the identification of the viral release time from the cells. The present study demonstrates that the same approach can be successfully exploited for the on-line monitoring of different enveloped and non-enveloped virus production kinetics in cell culture processes. The on-line monitoring multi-frequency capacitance method was assessed in human HEK293 and Sf9 insect cells expression systems, with viral productions initiated by either infection or transfection. The comparative analyses of all the data acquired indicate that the characteristic capacitance signals were highly correlated with the occurrence of viral replication phases. Furthermore the evolution of the cell dielectric properties (intracellular conductivity and membrane capacitance) were indicative of each main replication steps. In conclusion, multi-frequency capacitance has a great potential for on-line monitoring, supervision and control of viral vector production in cell culture processes.
authors.affiliation: NRC, Human Health Therapeutics Portfolio, 6100 Royalmount Ave, Montréal, QC, H4P 2R2, Canada; Virologie et Pathologie Humaine - VirPath Team, International Center for Infectious diseases Research, Inserm U1111, CNRS UMR5308, ENS Lyon, Université Claude Bernard Lyon 1, Faculté de Médecine RTH Laennec, Lyon, France. Electronic address: emma.petiot@univ-lyon1.fr.
authors.forename: Emma
authors.initials: E
authors.lastname: Petiot
authors.affiliation: NRC, Human Health Therapeutics Portfolio, 6100 Royalmount Ave, Montréal, QC, H4P 2R2, Canada. Electronic address: sven.ansorge@cnrc-nrc.gc.ca.
authors.forename: Sven
authors.initials: S
authors.lastname: Ansorge
authors.affiliation: Virologie et Pathologie Humaine - VirPath Team, International Center for Infectious diseases Research, Inserm U1111, CNRS UMR5308, ENS Lyon, Université Claude Bernard Lyon 1, Faculté de Médecine RTH Laennec, Lyon, France. Electronic address: manuel.rosa-calatrava@univ-lyon1.frm.
authors.forename: Manuel
authors.initials: M
authors.lastname: Rosa-Calatrava
authors.affiliation: NRC, Human Health Therapeutics Portfolio, 6100 Royalmount Ave, Montréal, QC, H4P 2R2, Canada; McGill University, Bioengineering Dpt. 817, Sherbrooke St. W., Montreal, QC, H2 B 2C6, Canada. Electronic address: amine.kamen@mcgill.ca.
authors.forename: Amine
authors.initials: A
authors.lastname: Kamen
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D019149:Bioreactors; D025802:Electric Capacitance; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D016086:Lentivirus / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D009975:Orthomyxoviridae / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D015203:Reproducibility of Results; D061987:Sf9 Cells; D014765:Viral Vaccines / Q000096:biosynthesis / Q000235:genetics; D014773:Virology / Q000379:methods; D019065:Virus Assembly / Q000502:physiology; D014779:Virus Replication / Q000502:physiology
chemical_list: D014765:Viral Vaccines
keywords: Capacitance probe; Characteristic frequency fc; Dielectric cell properties; Membrane capacitance; On-line monitoring; Permittivity; Viral infection; Virus production kinetics