B28-05 Genetic and Chemical Correction of the Cystic Fibrosis Transmembrane Receptor Reduces Airway Susceptibility to Viral Infection in an Induced Pluripotent Stem Cell Derived Airway Epithelium

Abstract Rationale The airway epithelium, a primary target for viral infection, plays a critical role in disease response—particularly in individuals with pre-existing airway conditions such as cystic fibrosis (CF). Previously individuals with CF have shown worsened outcomes with viral infection including influenza H1N1. During the SARS-CoV-2 pandemic, CF individuals were expected to have severe outcomes based on prior viral outbreaks; however, those on effective CFTR modulators showed milder disease. It is not well understood how alterations CF airway epithelium results in modified infectivity, viral replication genetics, changes in epithelial morphology and transcriptomic changes. We sought to address this deficiency by utilizing directed differentiation of induced pluripotent stem cell lines from CF patients matched with gene edited CFTR corrected controls grown to air liquid interface. This system allows for analysis of CFTR genotype specific effects of SARS-CoV-2 and IAV infection within an otherwise identical genetic background with and without highly effective CFTR modulator therapy Methods We used an iPSC-derived airway epithelium model of CF and syngeneic CFTR-corrected cells to examine responses to SARS-CoV-2 and IAV infection in the presence or absence of the highly effective CFTR modulator combination elexacaftor/tezacaftor/ivacaftor (ETI). iPSC derived airway epithelium was infected with either IAV (MOI 1) or SARS-CoV-2 (MOI 4) and harvested 24-48 hours post infection for transcriptional (RT-PCR, ScRNA-seq) and protein (IFA) analysis. Results CF iPSC-derived and primary airways were significantly more susceptible to viral infection and epithelial injury compared to their CFTR-corrected and non-CF counterparts. Strikingly, pretreatment with ETI conferred significant protection in CFTR-corrected and non-CF, wildtype airway epithelia, in both iPSC-derived and primary epithelial culture. Single-cell RNA sequencing analysis of SARS-CoV-2 infected samples confirmed a heightened infection and pro-inflammatory response in CF iPSC-airways, while ETI treatment significantly reduced these responses in both CF and CFTR-corrected iPSC-airways. Mechanistically, ETI treatment led to increased type I interferon signaling and induction of antiviral genes, while expression of other pro-inflammatory genes were suppressed in both CF and non-CF iPSC-airways. Conclusion These results underscore the therapeutic promise of CFTR-modulators like ETI in mitigating viral infection and inflammation, not only in CF airways but also in non-CF airways, highlighting the broad applicability of CFTR-modulators as a therapeutic strategy in viral pneumonia and inflammatory lung disease. This abstract is funded by: Cystic Fibrosis Foundation, NHBLI