Bulk RNA sequencing of SARS-CoV-2 infected alveolar type I- and type II like cells

Bulk RNA sequencing was performed on control and SARS-CoV-2 infected 2D bronchioalveolar-like and small airway cultures Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), may result in acute respiratory distress syndrome (ARDS), multi-organ failure and death. The alveolar epithelium is a major target of the virus, but representative models to study virus host interactions in more detail are currently lacking. Here, we describe a human 2D air-liquid interphase culture system which was characterized by confocal-, electron-microscopy and mRNA expression analysis. In this model, alveolar type I- (ATI-L) and type II-like (ATII-L) cells, but also basal cells, neuroendocrine cells and club cells, are grown from 3D self-renewing lung bud tip organoids. These cultures were readily infected by SARS-CoV-2 with both ATI-L and ATII-L cells being targeted. Consequently, significant viral titers were detected and mRNA expression analysis revealed induction of a type I/III interferon response program. Hence, these cultures represent an experimental model for SARS-CoV-2 infection and can be applied for drug screens. RNA was extracted from 2D pulmonary cultures that were either grown in expansion conditions (EXP) or differentiation conditions (DIF) and were not treated or SARS-CoV-2 for 72 hours. After this, RNA was collected.