Phd Candidate The University of Hong Kong, Hong Kong
Abstract: Human organoids derived from reprogrammed and tissue stem cells offer a valuable in vitro platform for studying human development, regeneration, and disease modeling. Current platforms mainly focus on generating airway epithelial cells from human ESCs and iPSCs but do not effectively translate complex communications across various cellular and tissue niches of the human airway. Moreover, there is a lack of consensus benchmarking standards across different organoid platforms and human samples. Addressing this knowledge and technological gap, we developed an improved method to create human airway organoids containing both epithelial and stromal lineages. These organoids exhibit functional motile ciliated cells and mucin-secreting submucosal gland cells within a well-organized pseudostratified epithelium, with transcriptomic profiles displaying a high similarity to human tissues. They contain a FOXF1+ fibroblast niche conserved in both fetal human and mouse airways. We introduced a co-culture approach incorporating blood-circulating monocytes, leading to enhanced mesenchymal-epithelial crosstalk, the emergence of fetal-specific pulmonary neuroendocrine cells, and the differentiation of monocytes into self-sustaining alveolar macrophages. Our multi-lineage organoid system, incorporating mesenchymal, immune, and epithelial cells, successfully recapitulates the cellular heterogeneity and organization of the human conducting airway and provides insights into the organized cell-cell interactions in the proximal airway. By presenting an integrated analysis using published single-cell RNA-seq datasets pertinent to the proximal airway of mice, humans as well as human organoids, we address current benchmarking progress and future challenges in the field. Our analyses underscore the importance of constructing a complex signaling niche for a better understanding of human tissue regeneration, highlighting the potential of this research in translating discoveries into clinical applications.
