Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has been identified as the etiologic agent for the Coronavirus Disease 2019 (COVID-19) outbreak that started in early December 2019. To date, COVID-19 has caused almost 6000 deaths in Malaysia since its first outbreak in January 2020.
Objective: Understanding the pathophysiology of the virus is important for the researchers to identify the potential targets against COVID-19. For this purpose, the virus must be isolated and propagated in a suitable host that allows the virus to grow well and at the same time would not cause immediate cell death to the host.
Method: In the effort to identify the best host cells for the propagation of SARS-CoV-2, we infected several mammalian cells lines (i.e., Vero, Vero E6, Calu-3, MRC-5, and A549) with different lineages of SARS-CoV-2 that are widely circulated in Malaysia.
Results: We found that SARS-CoV-2 multiplied only in Vero, Vero E6 and Calu-3 cells. Propagation of the virus in these cell lines were confirmed with real-time RT-PCR. Images from transmission electron microscopy (TEM) revealed multiplication of the virus in various vesicles of these cells. Multiplication of these viruses was accompanied by apoptosis of the host cells (cytopathic effect (CPE)) except for Calu-3 cells.
Conclusion: These findings revealed the potential of Calu-3 as the model cell line to assist scientists into recapitulating the relevant responses of SARS-CoV-2 infection in vitro.