Ventral anterior foregut endoderm cells as progenitors for airway epithelial cell replacement in primary ciliary dyskinesia

BackgroundLung transplantation remains the ultimate treatment option for patients with end-stage lung disease, but has many limitations. This underlines the urgent need of developing alternative approaches to treat lung disorders. Among the emergent strategies, gene therapy holds great potential for the treatment of monogenic lung diseases. However, so far, aerosolized viral vector-based delivery for gene therapy has failed likely because of difficulties in accessing the target cells. Combined gene and cell therapy approaches could be a promising alternative. Trials using basal cell transplantation already showed encouraging results. Moreover, the induced pluripotent stem cell (iPSC) technology broadens the scope of personalized therapies by paving the way for autologous approaches. Our group previously derived iPSC lines from patients with Primary Ciliary Dyskinesia (PCD) and found that their correction by gene conversion allows functional recovery. This study aimed to identify the best progenitors and airway conditioning technique to develop an autologous cell replacement strategy for PCD. MethodsAirway epithelial cells were differentiated from induced pluripotent stem cell (iPSC) lines from a healthy donor (parental Hy03) and Hy03 in which MCIDAS was knocked out (PCD model) and maintained in air-liquid interface (iALI). The engraftment of GFP+ ventral Anterior Foregut Endoderm (vAFE) cells, differentiated from GFP-expressing Hy03 iPSCs, was assessed after conditioning of the recipient iALI. The efficacy (epithelial cell shedding) and toxicity (cell death) of different conditioning strategies were compared. Cilia functional repair was assessed using microbead motion tracking. ResultsGFP+ vAFE cells can successfully integrate and repair trypsin- or EDTA-conditioned airway epithelia derived from the parental and MCIDAS-/- Hy03 iPSC lines. EDTA showed optimal efficacy/safety balance. Progenitor integration and differentiation were confirmed by E-cadherin, tubulin-IV, KRT5 and MUC5AC co-expression in GFP+ engrafted cells at day 35 post-graft (immunofluorescence analysis). The engrafted GFP+ population reached 35-45% of the total epithelial population, as indicated by flow cytometry quantification of EpCAM+/GFP+ cells. Functional analysis demonstrated cilia motion restoration after GFP+ cell engraftment onto MCIDAS-/- iALI. ConclusionsOur study shows that vAFE cells can integrate and differentiate to repair epithelial models of PCD. EDTA conditioning is promising for the clinical application of this therapeutic strategy.