JuNo: Joint Utilization of Novel Imaging Technology for AT2 Organoids

Alveolar type 2 (AT2) cells are essential for maintaining lung homeostasis, fulfill distinct secretory and immunoregulatory functions, can self-renew, and serve as AT1 progenitors. The transition of AT2 cells into mesenchymal cells is suspected to be essential for the development of lung fibrosis. However, the cellular plasticity and stem cell-like properties of AT2 cells lead to substantial heterogeneity in morphology and differentiation states. Thus, in-depth morphological characterization of AT2-derived organoids across stimulation experiments is crucial to better understand the process of epithelial-to-mesenchymal transition. Therefore, non-invasive tomographic imaging is required to investigate these morphological changes. Dynamic optical coherence tomography enables this with ~1 µm resolution and a functional contrast, based solely on signal fluctuations in time-series data. Further, B-Scan-rates of 125 Hz allow for volumetric measurements, capturing the dynamics of entire organoids. We applied this technique in primary human AT2-derived organoids from healthy human lung tissues (n=3) to demonstrate its suitability and were able to show various structural phenotypes. Moreover, outgrowing of organoids from matrigels, a yet unknown behaviour, could be observed.