Gestational and postnatal age define airway epithelial maturation and RSV responses during the first year of life: results of an ex-vivo/in-vitro Airway Epithelial Cell Study

Introduction Respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infection in infants globally. Newborns, especially those born prematurely, are at increased risk of severe RSV-related illness, yet the influence of age on early-life airway epithelium innate immune responses remains relatively understudied. Methods We established ex-vivo/in-vitro well-differentiated paediatric nasal epithelial cell (WD-PNEC) cultures derived from preterm and term infants at birth and again at 1-year old. Infection characteristics and innate immune responses were determined following in vitro RSV infection. Results RSV growth kinetics and cytopathology were similar irrespective of gestation or age. Secretion of interferon lambda-1 (IFN-λ1), CXCL10, CCL5 and CXCL8 was comparable between RSV-infected preterm-newborn and term-newborn WD-PNECs. Importantly, following RSV infection, secretion of RSV-induced IFN-λ1 (p