Generation of human-induced pluripotent stem cell-derived lung organoids for modeling respiratory syncytial virus infection and pulmonary injury.

BACKGROUND

Respiratory syncytial virus (RSV) is one of the common causes of lower respiratory infections in infants. Cell lines and animals are major models for studying RSV, but single cell type and species differences make them difficult to mimic human physiological features. Stem cell-derived organoids contain multiple cell types similar to native organs and model the physiological conditions of native organs.

METHODS

We used human lung organoids (HLOs) to investigate RSV infection. Immunofluorescent (IF) staining performed at 48 and 96 h post-infection to verified RSV target cells. Pro-inflammatory factor expression was assessed by RT-qPCR and ELISA. TUNEL+ apoptotic cells, Ki67+ proliferating cells, filopodia-like structures, and CDH1 (E-cadherin) expression were quantified at 96 h post-infection.

RESULTS

RSV-infected cells included epithelial cells and PDGFRβ+ cells. RSV induced pro-inflammatory factors and elicited significant changes in cell fate: increased TUNEL+ cells indicating enhanced apoptosis, and decreased Ki67+ cells reflecting impaired cell proliferation. Furthermore, morphological changes were evident in the infected HLOs. F-actin staining revealed a marked increase in filopodia-like structures, whereas CDH1 expression was significantly reduced. These observations indicate that RSV infection affects both cytoskeletal integrity and cadherin-mediated cell junctions in HLOs.

CONCLUSION

Our findings confirm HLOs provide a valuable model for studying RSV infection in vitro. HLOs infected with RSV have a similar cell distribution to native lung and provide evidence of actin cytoskeleton remodeling and impaired cell adhesion.