Lipid nanoparticle-encapsulated <i>Dnai1</i> mRNA rescues ciliary activity in primary ciliary dyskinesia mouse cell models

Primary ciliary dyskinesia (PCD) is a rare, genetically heterogenous disorder resulting from dysfunctional motile cilia that is characterized by chronic, progressive lung disease with currently no corrective therapies available. Here, we test the efficacy of selective organ targeting lipid nanoparticles (SORT-LNPs) that were optimized for potency and delivery to respiratory cells containing an mRNA encoding an axonemal protein to rescue ciliary activity in a murine culture model of PCD. Utilizing murine nasopharyngeal epithelial cell (mNPEC) cultures isolated from a conditional Dnai1 knockout mouse model of the known human PCD-associated gene DNAI1 homolog, we tested if SORT-LNPs containing an optimized Dnai1 mRNA could rescue ciliary activity. Treatment of differentiating and well-differentiated Dnai1 knockout mNPECs with SORT-LNP-Dnai1 mRNA led to a dose-dependent increase in levels of DNAI1 protein and incorporation into ciliary axonemes, resulting in rescued ciliary activity with normal ciliary beat frequency that persisted for over 3 weeks. These data support further clinical development of an mRNA-based therapeutic with LNP-mediated delivery as a treatment for individuals with PCD with disease-causing DNAI1 mutations.