Lipid and nucleocapsid N-protein accumulation in COVID-19 patient lung and infected cells

Grootemaat, Anita E.; van der Niet, Sanne; Scholl, Edwin R.; Roos, Eva; Schurink, Bernadette; Bugiani, Marianna; Miller, Sara E.; Larsen, Per; Pankras, Jeannette; Reits, Eric A.; van der Wel, Nicole N.

The pandemic of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global outbreak and prompted an enormous research effort. Still, the subcellular localization of the corona virus in lungs of COVID-19 patients is not well understood. Here, the localization of the SARS-CoV-2 proteins is studied in postmortem lung material of COVID-19 patients and in SARS- CoV-2 infected Vero cells, processed identically. Correlative light and electron microscopy on semi- thick cryo-sections, demonstrated induction of electron-lucent, lipid filled compartments after SARS- CoV-2 infection in both lung and cell cultures. In lung tissue, the non-structural protein 4 and the stable nucleocapsid N-protein, were detected on these novel lipid filled compartments. The induction of such lipid filled compartments and the localization of the viral proteins in lung of patients with fatal COVID-19, may explain the extensive inflammatory response and provide a new hallmark for SARS- Cov-2 infection at the final, fatal stage of infection.