RT Journal Article SR Electronic T1 Human induced pluripotent stem cell-derived alveolar type 2 cells mature at air-liquid interface and respond to airborne stimuli JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 4648 DO 10.1183/13993003.congress-2022.4648 VO 60 IS suppl 66 A1 K Abo A1 A Wilson YR 2022 UL http://erj.ersjournals.com/content/60/suppl_66/4648.abstract AB Human alveolar type II cells (AT2s) are progenitors of the alveolar epithelium and are among the pulmonary cells that are directly exposed to inhaled stimuli. Primary human AT2s can be cultured in three-dimensional alveolospheres, but are difficult to culture in the physiologically relevant air-liquid interface (ALI) format. Human induced pluripotent stem cells (iPSCs) can be directed to differentiate to iPSC-derived AT2s (iAT2s) in alveolospheres, where they transcriptomically resemble fetal lung. Here we report the successful adaptation of iAT2s to ALI culture, which promotes their maturation and permits exposure to inhaled stimuli. We transcriptomically profile iAT2s cultured at ALI and find that they mature as they downregulate cell cycle-associated transcripts. We then evaluate the extent of iAT2 maturation at ALI within the developmental context by comparison to primary AT2s. We find that iAT2s at ALI are more similar to primary AT2s than iAT2s cultured as spheres, and that differences are driven by primary AT2sā€™ response to immune stimuli. We then test the capacity of iAT2s to respond to immune stimuli by infecting with SARS-CoV-2. We find that iAT2s mount an epithelial-intrinsic interferon and inflammatory response to SARS-CoV-2 infection, and can serve as a platform for testing antiviral therapeutics. Finally, we demonstrate that iAT2s at ALI respond to cigarette smoke and electronic cigarette vapor, enabling the direct comparison of these common inhaled stimuli. Overall, we describe a novel disease modeling platform that will enable exploration of gene-environment interactions unique to inhaled exposures of the alveolar epithelium.FootnotesCite this article as Eur Respir J 2022; 60: Suppl. 66, 4648.This article was presented at the 2022 ERS International Congress, in session ā€œ-ā€.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).