Figure 1.

S. mansoni lipid-enriched extracellular vesicles trigger eosinophil tissue repair. S. mansoni eggs and worms release extracellular vesicles exosomes enriched in nucleic acid, proteins, cholesterol, and lipids including LPC and DP1. Packaging in the bilayer of exosomes protects lipids from enzymatic degradation once released in the inflammatory milieu as a component of the helminth excretory/secretory product allowing LPC and PGD2 to be targeted for delivery and recognition by TLR2 and PDG1, respectively, on the surface of eosinophils. Activation of TLR2 and DP1 by S. mansoni-derived exosomes drives lipid droplet accumulation within eosinophils and release of pro-fibrotic TGF-β to drive fibrosis in the granuloma or epithelium.