SARS-CoV-2 replication in hepatocyte cell lines

Background: A high proportion of patients with COVID-19 demonstrate liver enzyme abnormalities which have been attributed to a variety of etiologies including sepsis, coagulopathy with ischemic injury, and drug effects. We sought to determine the potential for replication and injury due to SARS-CoV-2 infection of hepatocyte cells. Methods: SARS-CoV-2 viral stocks were obtained from ATCC and expanded in Vero E6 cells. The virus was diluted to a multiplicity of infection of 0.1 plaque forming units and placed in medium overlying confluent cells. HepG2 andHuh7.5 hepatocyte cell lines were utilized, with Vero E6 cells (kidney) and WI-38 (lung) cell cultures serving as infection controls. For each cell line, uninfected cells were also maintained for comparison. Infection experiments were run in triplicate. Plaque assays were used to determine supernatant viral titer on days 2 through 8 post infection. Cell culture morphology was monitored by light microscopy. Results: All cell lines demonstrated significant replication potential with multi-log increase in plaque-forming units by day 3 post-infection. Rapid replication was observed through day 5. This was associated with the presence of severe cell injury with loss of attachment of the monolayer, suggesting that hepatocyte cell death limited overall levels of viral replication. Conclusion: Both HepG2 and Huh7.5 cell lines support active replication of SARS-CoV-2, leading to multi-log increases in viral titer. Replication in these cell lines is accompanied by severe injury leading to loss of attachment and cell death. These findings support the concept that SARS-CoV-2 infection may be associated with liver enzyme abnormalities due to acute viral-induced liver injury. (Table Presented).