Human airway submucosal gland organoids to study respiratory inflammation and infection [bulk RNA-seq]

The human airway lining consists of two physiologically distinct compartments: the surface airway epithelium (SAE) and the submucosal glands (SMGs). Despite their critical role, SMGs have remained largely overlooked in airway in vitro modeling of respiratory inflammation and infection. In this study, we leverage long-term cultured organoids derived separately from SAE and SMG to investigate their unique physiological characteristics. Single-cell RNA sequencing (scRNA-seq) analysis confirms that these organoid models accurately replicate the cellular heterogeneity inherent to each tissue type. Specifically, SMG organoids are enriched in MUC5B-producing mucous cells and generate alpha-Smooth Muscle Actin (αSMA)-expressing myoepithelial cells. We identify ANPEP/CD13 as a specific cell surface marker for SMG secretory cells. Exposure to cytokines elicits distinct transcriptomic responses in SMG secretory cells, providing insights into the cellular mechanisms underpinning inflammatory pathogenesis. Infection assays with human alpha-coronavirus 229E (HCoV-229E) reveal a selective vulnerability of CD13-positive secretory cells within SMG organoids, triggering a specific unfolded protein response associated with endoplasmic reticulum (ER) stress. These findings broaden the utility of airway organoids for precision modeling of respiratory (patho-)physiology