Induced Pluripotent Stem Cell Derived Airway to Assess Cystic Fibrosis Intrinsic Epithelial Response to SARS-CoV-2​

Abstract

Rationale There is a lack of knowledge of how CFTR-deficient airway epithelium intrinsically responds to SARS-CoV-2. Though prior work has demonstrated altered CF airway expression of viral entry factors, it is unknown whether these alterations are protective and whether they reflect host genetic variation or secondary response of chronic inflammation. We address this gap by infecting induced pluripotent stem cell (iPSC)-derived airways from CF patients and syngeneic CFTR-corrected controls with SARS-CoV-2 and assessing differential susceptibility to infection and inflammatory and anti-viral response. MethodsCF (F508del homozygous) and syngeneic CFTR-corrected (CRISPR-Cas9) iPSC- were differentiated into airway epithelium cultured at airliquid interface (ALI) by a directed differentiation protocol that generates a pure population of major and rare airway cell-types. After 21 days in ALI culture, the iPSC-airway were infected with either mock or SARS-CoV-2 (isolate USA-WA1/2020) with MOI of 4, and harvested at 0, 1, 3 days post infection (dpi) for RT-PCR and immune-stainingResultsBoth CF and CFTR-corrected iPSC-airway express viral entry factors of ACE2 and TMPRSS2, and are permissive to SARS-CoV-2 infection. CF iPSC-airway exhibited significantly increase in SARS-CoV-2 nucleocapsid protein (N) transcript at 1 dpi, accompanied by increases in IFN2, RSAD2, and CXCL10 at 3 dpi, compared to its CFTR-corrected counter-part. There are no baseline significant differences in ACE2, TMPRSS2, TP63, NGFR, MUC5B, MUC5AC, SCGB1A1, FOXJ1, FOXI1 expression between CF and CFTR-corrected iPSC-airway before SARS-CoV-2 infection. ConclusionsOur preliminary studies indicate increased early SARS-CoV-2 infection in CFTR-deficient epithelium with accompanied subsequent rise in anti-viral and inflammatory response compared to its genetically controlled CFTR-corrected counterpart. Future studies are aimed at assessing differential CF epithelial kinetics of SARS-CoV-2 viral entry and replication, morphological changes, global transcriptomic response, and how treatment with CFTRmodulator would alter the epithelial response. Ultimately, we aim to establish a reductionist, physiologically relevant model system that is coupled with gene-editing technology to study intrinsic CF epithelial response to SARS-CoV-2, which would generate insights to aid practice guidelines for CF patients, and open future directions to evaluate gene-specific mechanisms of airway response to pathogens. (Figure Presented).