Esther, C. R. | bioRxiv Science

bioRxiv2025

Airway Epithelial SARS-CoV-2 Infectious and Repair Responses: Relationships to Age, Sex, and Post-COVID Pulmonary Syndromes

The long-term pulmonary sequelae of SARS-CoV-2 respiratory infections reflect infection severity, innate and adaptive immunity, and respiratory epithelial repair. This study investigated the acute and reparative responses as a function of age and sex in primary human bronchial epithelial (HBE) cultures utilizing a 14-day SARS-CoV-2 infection protocol. SARS-CoV-2 infection peaked at 3 days post-infection (dpi) with an [~] 2 log titer suppression at 14 dpi. SARS-CoV-2 infection induced interferon, interferon-induced gene, and cell damage responses. No age- or sex-dependent effects on SARS-CoV-2 infection were detected. Airway epithelia repaired to an abnormal mucus metaplastic/inflammatory state that reflected potentially beneficial and adverse consequences at 14 dpi. Repair processes were infection severity-dependent, not sex-dependent, and were more robust in young donor cultures. Analyses of long-COVID subjects with persistent pulmonary fibrosis or persistent bronchitic airway diseases exhibited expression of HBE 14 dpi failed repair gene signatures, including ISG gene signatures. Human airway epithelial repair post-SARS-CoV-2 is prolonged and incomplete in vitro over 14 days, and persistently abnormal repair may contribute to phenotypes of people with long-COVID pulmonary syndrome.

cell biology↗

bioRxiv2024

Dysregulated Airway Host Defense in Hyper IgE Syndrome due to STAT3 Mutations

RationaleHyper IgE syndrome (STAT3-HIES), also known as Jobs syndrome, is a rare immunodeficiency disease typically caused by dominant-negative STAT3 mutations. STAT3-HIES syndrome is characterized by chronic pulmonary infection and inflammation, suggesting impairment of pulmonary innate host defense. ObjectivesTo identify airway epithelial host defense defects consequent to STAT3 mutations that, in addition to reported mutant STAT3 immunologic abnormalities, produce pulmonary infection. MethodsSTAT3-HIES sputum was evaluated for biochemical/biophysical properties. STAT3-HIES excised lungs were harvested for histology; bronchial brush samples were collected for RNA sequencing and in vitro culture. A STAT3-HIES-specific mutation (R382W), expressed by lentiviruses, and a STAT3 knockout, generated by CRISPR/Cas9, were maintained in normal human bronchial epithelia under basal or inflammatory (IL1{beta}) conditions. Effects of STAT3 deficiency on transcriptomics, and epithelial ion channel, secretory, antimicrobial, and ciliary functions were assessed. Measurements and Main ResultsMucus concentrations and viscoelasticity were increased in STAT3-HIES sputum. STAT3-HIES excised lungs exhibited mucus obstruction and elevated IL1{beta} expression. STAT3 deficiency impaired CFTR-dependent fluid and mucin secretion, inhibited expression of antimicrobial peptides, cytokines, and chemokines, and acidified airway surface liquid at baseline and post-IL1{beta} exposure in vitro. Notably, mutant STAT3 suppressed IL1R1 expression. STAT3 mutations also inhibited ciliogenesis in vivo and impaired mucociliary transport in vitro, a process mediated via HES6 suppression. Administration of a {gamma}-secretase inhibitor increased HES6 expression and improved ciliogenesis in STAT3 R382W mutant cells. ConclusionsSTAT3 dysfunction leads to multi-component defects in airway epithelial innate defense, which, in conjunction with STAT3-HIES immune deficiency, contributes to chronic pulmonary infection.

cell biology↗