Small extracellular vesicle-mediated epithelial–macrophage crosstalk contributes to macrophage dysfunction during PEDV infection

Abstract Mucosal immune defense depends on coordinated communication between epithelial and immune cells, yet pathogens can disrupt this crosstalk through diverse mechanisms. Here we show that porcine epidemic diarrhea virus (PEDV), an enteric alphacoronavirus, reshapes epithelial small extracellular vesicle (sEV) signaling to impair macrophage function. Despite detection by the intestinal innate immune system, PEDV promotes the release of epithelial sEVs enriched in immunoregulatory noncoding RNAs. Among this cargo, miR-190a targets the actin-regulating protein TMOD3 and disrupts F-actin remodeling, reducing macrophage migration. In parallel, the long noncoding RNA TS2083 promotes annexin A2 degradation, impairing phagocytic cup formation and suppressing phagocytosis. Moreover, serum sEVs from PEDV-infected piglets are enriched in both RNAs and impair isolated alveolar macrophage migration and phagocytosis, suggesting distal macrophage modulation. Collectively, these findings implicate sEV-mediated macrophage reprogramming in PEDV-mediated immune evasion and highlight sEV-associated RNAs as potential biomarkers of PEDV infection and therapeutic targets for restoring macrophage-mediated mucosal immunity.