An Evaluation of Different Types of Peptone as Partial Substitutes for Animal-derived Serum in Vero Cell Culture

Abstract

Vero cells are one of the most frequently used cell types in virology. They can be used not only as a vehicle for the replication of viruses, but also as a model for investigating viral infectivity, cytopathology and vaccine production. There is increasing awareness of the need to limit the use of animal-derived components in cell culture media for a number of reasons, which include reducing the risk of contamination and decreasing costs related to the downstream processing of commercial products obtained via cell culture. The current study evaluates the use of protein hydrolysates (PHLs), also known as peptones, as partial substitutes for fetal bovine serum (FBS) in Vero cell culture. Eleven plant-based, two yeast-based, and three casein-based peptones were assessed, with different batches evaluated in the study. We tested the effects of three concentration ratios of FBS and peptone on Vero cell proliferation, four days after the initial cell seeding. Some of the tested peptones, when in combination with a minimal 1% level of FBS, supported cell proliferation rates equivalent to those achieved with 10% FBS. Collectively, our findings showed that plant-based peptones could represent promising options for the successful formulation of serum-reduced cell culture media for vaccine production. This is especially relevant in the context of the current COVID-19 pandemic, in view of the urgent need for SARS-CoV-2 virus production for certain types of vaccine. The current study contributes to the Three Rs principle of reduction, as well as addressing animal ethics concerns associated with FBS, by repurposing PHLs for use in cell culture.

Development of Low-Serum Culture Media for the in Vitro Cultivation of Theileria annulata S15 Cell Line

“…For instance, several commercial peptones were utilized for optimizing the culture of CHO cells, and they resulted in encouraging effects on biomass production ( 10 ). Peptone’s ability to promote cell growth has also been reported in other studies ( 23 , 24 ). Although recombinant supplements and additives, such as growth factors, can be used in serum-free media, their utilization is not always cost-effective ( 25 ).…”

Elucidating the Effectiveness of Antibiotic Treatments in Eliminating the Black Dots Contamination from Vero Cell Line Culture

“…For instance, an antibiotic may interfere with the development of cell walls, alter chromosomal topology by affecting DNA gyrase, and prevent the production of DNA, RNA, and proteins 16 . It is widely accepted that using antibiotics in cultured cells has little/no effect on gene expression 17,18 . Some research groups reported the elimination of black dots from cell culture by using Ampicillin and Gentamicin at the concentration of 50 μg/ml alone and combining these antibiotics at 100 μg/ml for five days 9, 19 .…”

Editorial

“…Transition toward animal-component free medium for Vero cell culture is also explored in this issue, by Lezin et al 3 As discussed by the authors, there are currently several serum-free formulations available for use in the proliferation and expansion of Vero cells. However, their cost can be prohibitive, and their use in culture requires careful optimisation for best cell growth.…”