Virus propagation methods generally use transformed cell lines to grow viruses from clinical specimens, which may force viruses to rapidly adapt to cell culture conditions, a process facilitated by high viral mutation rates. Upon propagation in VeroE6 cells, SARS-CoV-2 may mutate or delete the multibasic cleavage site (MBCS) in the spike protein. Previously, we showed that the MBCS facilitates serine protease-mediated entry into human airway cells (Mykytyn et al., 2021). Here, we report that propagating SARS-CoV-2 on the human airway cell line Calu-3 - that expresses serine proteases - prevents cell culture adaptations in the MBCS and directly adjacent to the MBCS (S686G). Similar results were obtained using a human airway organoid-based culture system for SARS-CoV-2 propagation. Thus, in-depth knowledge on the biology of a virus can be used to establish methods to prevent cell culture adaptation.
All scripts used for data processing are deposited in GitHub: https://github.com/wchnicholas/SARS_CoV2_mutation. Raw sequencing data are available at the NIH Short Read Archive under accession number: BioProject PRJNA694097.
Human airway cells prevent SARS-CoV-2 multibasic cleavage site cell culture adaptationNCBI BioProject, PRJNA694097.
- Bart L Haagmans
- Bart L Haagmans
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Mark Marsh, University College London, United Kingdom
- Received: January 22, 2021
- Accepted: April 8, 2021
- Accepted Manuscript published: April 9, 2021 (version 1)
© 2021, Lamers et al.
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