Optimization of an adenovirus-vectored zoster vaccine production process with chemically defined medium and a perfusion system

Objectives Cells grown in chemically defined medium are sensitive to shear force, potentially resulting in decreased cell growth. We optimized the perfusion process for HEK293 cell-based recombinant adenovirus-vectored zoster vaccine (Ad-HER) production with chemically defined medium. Methods We first studied the pseudo-continuous strategies in shake flasks as a mimic of the bioreactor equipped with perfusion systems. Using design of experiment (DoE) in shake flasks, we obtained the regression models between Ad-HER titer/virus input-output ratio and three production process parameters: time of infection (TOI), multiplicity of infection (MOI), and virus production pH (pH). We then confirmed the effect of Pluronic F68 (PF-68) at 3.0 g/L on HEK293 cell growth and Ad-HER production in shake flasks and a 2 L benchtop bioreactor. Results The optimized process was scale-up to a 2 L benchtop bioreactor with the PATFP perfusion system, which yielded cell density of 7.4 x 10(6) cells/mL and Ad-HER titer of 9.8 x 10(9) IFU/mL at 2 dpi, comparable to the bioreactor with a ATF2 system. Conclusion This optimization strategy could be used to develop a robust process with stable cell culture performance and adenovirus titer. Increasing PF-68 concentration in chemically defined medium could protect cells from shear stress generated by perfusion system.

Automated summary

This study optimized the perfusion process for cell culture to improve the stability and adenovirus titer. The addition of PF-68 in chemically defined medium was found to protect cells from shear stress caused by the perfusion system.