Performance Comparison of Recombinant Baculovirus and Rabies Virus-like Particles production Using Two Culture Platforms

Abstract

This work aimed to assess, following upstream optimization in Schott flasks, the scalability from this culture platform to a stirred-tank bioreactor in order to yield rabies-recombinant baculovirus, bearing genes of G (BVG) and M (BVM) proteins, and to obtain rabies virus-like particles (VLP) from them, using Sf9 insect cells as a host. Equivalent assays in Schott flasks and a bioreactor were performed to compare both systems and a multivariate statistical approach was also carried out to maximize VLP production as a function of BVG and BVM’s multiplicity of infection (MOI) and harvest time (HT). Viable cell density, cell viability, virus titer, BVG and BVM quantification by dot-blot, and BVG quantification by Enzyme-Linked Immunosorbent Assay (ELISA) were monitored throughout the assays. Furthermore, transmission electron microscopy was used to characterize rabies VLP. The optimal combination for maximum VLP expression was BVG and BVM MOI of 2.3 pfu/cell and 5.1 pfu/cell, respectively, and 108 h of harvest time. The current study confirmed that the utilization of Schott flasks and a benchtop bioreactor under the conditions applied herein are equivalent regarding the cell death kinetics corresponding to the recombinant baculovirus infection process in Sf9 cells. According to the results, the hydrodynamic and chemical differences in both systems seem to greatly affect the virus and VLP integrity after release.

Monitoring by Raman spectroscopy of rabies virus‐like particles production since the initial development stages

“…This result can be confirmed, as previous studies comparing the performance of recombinant baculovirus production and rabies VLPs in Schott flasks and bioreactors concluded that, under specific conditions, both culture platforms are equivalent in the infection process. However, hydrodynamic and chemical differences affect viral stability and VLPs, making Schott flasks the suitable culture system for optimizing parameters in experiments of this kind 33 …”

“…The bioreactor experiments were like those performed in Schott flasks when the spectra were acquired as soon as the samples were removed (in line). The primary data from the experiments conducted in the bioreactor were published in a previously published article 33 …”

“…The primary data from the experiments conducted in the bioreactor were published in a previously published article. 33 2). (C) Filtered spectra according to G-J preprocessing approaches (Table 2).…”

“…However, hydrodynamic and chemical differences affect viral stability and VLPs, making Schott flasks the suitable culture system for optimizing parameters in experiments of this kind. 33…”