Stable iPSC-derived NKX2-1+ Lung Bud Tip Progenitor Organoids Give Rise to Airway and Alveolar Cell Types

Bud tip progenitors (BTPs) in the developing lung give rise to all epithelial cell types found in the airways and alveoli. The current work aimed to develop an iPSC organoid model enriched with stable NKX2-1+ BTP-like cells. Building on prior work, we optimized a directed differentiation paradigm to generate spheroids with robust NKX2-1 expression. Spheroids were expanded into organoids that possessed NKX2-1+/CPM+ BTP-like cells, which increased in number over time. Single cell RNA-sequencing analysis revealed a high degree of transcriptional similarity between induced BTPs (iBTPs) and in vivo BTPs. Using FACS, iBTPs can be purified and expanded as induced bud tip organoids (iBTO), which maintain an enriched population of bud tip progenitors. When iBTOs are directed to differentiate into airway or alveolar cell types using well-established methods, they give rise to organoids composed of organized airway or alveolar epithelium, respectively. Collectively, iBTOs are transcriptionally and functionally similar to in vivo BTPs, providing an important model to study human lung development and differentiation. SUMMARY STATEMENTiPSC-derived lung bud tip progenitors emerge in organoid culture, can be isolated and expanded, are transcriptionally similar to primary bud tip progenitors, and can differentiate into airway or alveolar organoids.