A biomarker identified by integrated bronchoalveolar lavage fluid and lung tissue lipidomics mitigates respiratory syncytial virus infection

Respiratory syncytial virus (RSV) is a highly pathogenic respiratory virus that severely impacts infants under 2 years, adults over 60, and immunocompromised individuals. Currently, no safe, low-toxicity, or cost-effective therapy is available for RSV. Research indicates that RSV infection disrupts pulmonary surfactant lipid metabolism. Through lipidomic analysis of bronchoalveolar lavage (BAL) fluid and lung tissue, we observed an increase in most phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs), while all phosphatidylglycerols (PGs) decreased. Additionally, all lysophospholipids in lung tissue increased. Among the altered lipids, 27 showed significant changes in both BAL fluid and lung tissue, including 15 phospholipids (7 PCs, 5 PEs, 3 PGs, and 1 phosphatidylinositol (PI)). From the decreased PGs, we identified an active lipid, PG 16:0–18:2, which correlated strongly between BAL fluid and lung tissue. Further studies confirmed that PG 16:0–18:2 significantly reduces viral load, mitigates RSV-induced lung damage, and reduces pulmonary inflammation. In vitro experiments demonstrated that PG 16:0–18:2 directly inhibits RSV replication and proliferation in epithelial cells. These findings suggest that PG 16:0–18:2 could serve as an effective and non-toxic antiviral agent, offering a promising complementary approach to RSV treatment.