Développement d'un système innovant de type organoïde pulmonaire pour modéliser la bronchopneumopathie chronique obstructive (BPCO)

Airflow limitation is the hallmark of obstructive pulmonary diseases, with the distal airways being a major site of obstruction. Despite the availability of multiple in vitro bronchial models, no culture system currently replicates the architecture and function of small airways in obstructive diseases. During my thesis, I aimed to engineer a so-called bronchioid model by encapsulating human bronchial adult stem cells derived from clinical samples within an alginate-based tubular scaffold. This system enabled the spontaneous self-organization of epithelial cells into a tubular structure mimicking the bronchiolar architecture. Collapse of the tube was observed within a few days; however, the addition of Y27632, a ROCK inhibitor, allowed the bronchioid to be maintained in culture for up to 21 days with good viability. Three-dimensional imaging, gene expression analysis (RT-qPCR and single cell transcriptomic) and flow cytometry confirmed epithelial differentiation into ciliated and goblet cells, as well as the formation of epithelial junctions. In bronchioids derived from cells from patients with COPD we evidenced altered differentiation of epithelial cells with a more secretory phenotype. Ciliary beating was observed, with a decreased frequency in bronchioids derived from COPD patients. Epithelial cells were infected with rhinovirus, which was introduced into the lumen of the model. It was also possible to establish an air–liquid interface by perfusing air at a controlled flow rate. This air–liquid interface appears to modulate the expression of certain genes. To further enhance the model, a concentric peripheral layer of smooth muscle cells was added, simulating the epithelial-mesenchymal trophic unit. Their capacity for contraction and proliferation was assessed, and epithelial-mesenchymal interactions were analysed using immunostaining, RT-qPCR, and flow cytometry. Here, we provide proof of concept for a perfusable bronchioid with proper mucociliary and contractile functions. The key advantages of this approach—air‒liquid interface integration, lumen accessibility, potential integration of different cell types, pathological feature recapitulation—position our pulmonary organoid model as a powerful tool for preclinical studies.