Respiratory Syncytial Virus Infection Does Not Induce Epithelial-Mesenchymal Transition

Area of Science:

• Pulmonology
• Virology
• Cell Biology

Background:

• Respiratory syncytial virus (RSV) causes severe disease in vulnerable populations.
• RSV infection is known to cause bronchial wall thickening in vitro.
• It remains unclear if RSV-induced airway changes mimic epithelial-mesenchymal transition (EMT).

Purpose of the Study:

• To investigate whether RSV infection induces EMT in lung epithelial models.
• To compare RSV-induced cellular changes with those induced by a known EMT inducer, TGF-β1.

Main Methods:

• Utilized three in vitro lung models: A549 cell line, primary human bronchial epithelial cells, and pseudostratified airway epithelium.
• Analyzed cell morphology changes, including surface area and perimeter.
• Performed genome-wide transcriptome analysis to compare gene expression patterns.

Main Results:

• RSV infection increased airway epithelial cell surface area and perimeter, unlike TGF-β1-induced cell elongation.
• Genome-wide transcriptome analysis showed distinct gene modulation patterns between RSV and TGF-β1.
• RSV did not induce EMT in any of the tested in vitro lung models.

Conclusions:

• RSV infection does not induce epithelial-mesenchymal transition (EMT) in various in vitro lung models.
• RSV-induced changes in airway epithelial cell morphology are distinct from EMT.
• RSV modulates actin polymerization, leading to noncanonical bronchial wall thickening, not EMT.