High titer oncolytic measles virus production process by integration of dielectric spectroscopy as online monitoring system

Abstract

Oncolytic viruses offer new hope to millions of patients with incurable cancer. One promising class of oncolytic viruses is Measles virus, but its broad administration to cancer patients is currently hampered by the inability to produce the large amounts of virus needed for treatment (10 -10 virus particles per dose). Measles virus is unstable, leading to very low virus titers during production. The time of infection and time of harvest are therefore critical parameters in a Measles virus production process, and their optimization requires an accurate online monitoring system. We integrated a probe based on dielectric spectroscopy (DS) into a stirred tank reactor to characterize the Measles virus production process in adherent growing Vero cells. We found that DS could be used to monitor cell adhesion on the microcarrier and that the optimal virus harvest time correlated with the global maximum permittivity signal. In 16 independent bioreactor runs, the maximum Measles virus titer was achieved approximately 40 hr after the permittivity maximum. Compared to an uncontrolled Measles virus production process, the integration of DS increased the maximum virus concentration by more than three orders of magnitude. This was sufficient to achieve an active Measles virus concentration of > 10 TCID ml .

Enabling PAT in insect cell bioprocesses: In situ monitoring of recombinant adeno‐associated virus production by fluorescence spectroscopy

“…The aim of this study was the development of a fluorescence spectroscopy based approach to monitor rAAV production in IC‐BEVS to enable PAT implementation in this system. Fluorescence spectra predictive power was maximized through a combination of preprocessing techniques, efficiently circumventing the strong fluorescence background of insect cell culture medium to predict rAAV production profiles and supporting the time of harvest decision, an important process parameter for virus‐based processes (Grein et al, ; Nikolay et al, ).…”

“…Fluorescence spectra predictive power was maximized through a combination of preprocessing techniques, efficiently circumventing the strong fluorescence background of insect cell culture medium to predict rAAV production profiles and supporting the time of harvest Table S2. rAAV, recombinant adeno-associated virus [Color figure can be viewed at wileyonlinelibrary.com] decision, an important process parameter for virus-based processes (Grein et al, 2018;Nikolay et al, 2018).…”

Tangential Flow Filtration for the Concentration of Oncolytic Measles Virus: The Influence of Filter Properties and the Cell Culture Medium

“…Measles virus (MV) is a leading candidate owing to the excellent safety profile of the measles vaccine [2]. However, at least 10 8 infectious MV particles are needed per dose for cancer therapy [3,4] and this has prompted extensive studies focusing on the optimization of upstream processes [5][6][7][8][9][10]. The deeper understanding of MV production gained from these studies has shown that shear stress and aeration play a key role in process productivity [7].…”

Cytoplasmic conductivity as a marker for bioprocess monitoring: Study of Chinese hamster ovary cells under nutrient deprivation and reintroduction

“…Carvell and Dowd (2006) Vero cells Enhancement of product yield in the virus production process Different parameters such as permittivity, conductivity, cell size, and concentration were monitored during the measles virus production process using dielectric spectroscopy to enhance the product quality and yield. Grein et al (2018)…”

“…The majority of the available dielectric based label‐free methods for monitoring biomass in a batch culture are based on bulk measurements. Dielectric spectroscopy techniques use the average dielectric properties of the cell culture medium to estimate the concentration of cells and their dielectric properties (Ansorge et al, ; Asami, Takahashi, & Takashima, ; Asami & Yamaguchi, ; Cannizzaro et al, ; Cole et al, ; Courtès et al, ; Druzinec et al, ; Grein et al, ; Justice et al, ; Katsumoto et al, ; Opel et al, ; Ron et al, ). Employing dielectric spectroscopy, also known as capacitance measurement, for real‐time in situ monitoring of the biomass content in fed‐batch cultures has been demonstrated to be successful in the estimation of dielectric properties and hence the physiological state of the cells (Ansorge et al, ; Petiot et al, ).…”