Organoid Models of SARS-CoV-2 Infection: What Have We Learned about COVID-19?

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which was classified as a pandemic in March 2020. As of 22 January 2022, globally more than 347 million cases of COVID-19 have been diagnosed, with 5.6 million deaths, making it the deadliest pandemic since the influenza pandemic in 1918. The clinical presentation of COVID-19-related illness spans from asymptomatic to mild respiratory symptoms akin to influenza infection to acute symptoms, including pneumonia necessitating hospitalisation and admission to intensive care units. COVID-19 starts in the upper respiratory tract and lungs but in severe cases can also involve the heart, blood vessels, brain, liver, kidneys and intestine. The increasing global health and economic burden of COVID-19 necessitates an urgent and global response. Understanding the functional characteristics and cellular tropism of SARS-CoV-2, and the pathogenesis that leads to multi-organ failure and death, has prompted an unprecedented adoption of organoid models. Successful drug discovery and vaccine development rely on pre-clinical models that faithfully recapitulate the viral life cycle and the host cell response to infection. Human stem cell-derived organoids fulfill these criteria. Here we highlight the role of organoids in the study of SARS-CoV-2 infection and modelling of COVID-19 pathogenesis.