Introduction
COPD is a disease influenced by the environment and the epigenetic modifications it causes. This pathology could be the result of a profound dysfunction of epithelial repair. We aim to improve the repair of COPD airway epithelium by grafting pre-differentiated induced pluripotent stem cells (iPSCs) from the same patient.

Methods
Epithelial cells from bronchial biopsies were cultured in the air-liquid interface (ALI) and underwent epithelial injury. iPSC-derived epithelial cells generated from patient blood (E. Ahmed et al., Stem Cell Res, 2021) and engineered to express GFP were differentiated to the vAFE early maturation stage and added to the lesion site. GFP expression was monitored by fluorescence microscopy from engraftment to 42 days to monitor cell repair and differentiation. Cultures were then fixed in formaldehyde for immunofluorescence (GFP, eCAD, p63, tubIV), and scRNAseq analysis was performed.

Results
GFP+ cells derived from vAFE-stage iPSCs were successfully grafted onto ALI epithelial lesions, as confirmed by fluorescence microscopy. The GFP signal was detected on day 3, intensified on day 7 and persisted until day 42, indicating the long-term viability of the grafted cells. Immunofluorescence at day 7 revealed that GFP+ cells formed intercellular junctions (eCAD) with GFP- cells and at day 42 differentiated into p63+ basal cells and tubIV+ ciliated cells. These results were validated by scRNAseq.

Conclusion
iPSC-derived epithelium can repair the pathological epithelium of COPD patients, offering insights into therapeutic approaches targeting epigenetics and cell therapy. The next phase will focus on in vivo development, assessing safety and efficacy in an immunodeficient mini-pig model.