The nanoparticulate lipid secretome in the lifecycle of Oesophagostomum dentatum: Shedding light on the role in parasitic development

The parasitic nematode Oesophagostomum dentatum, a member of the order Strongylida, commonly infects pigs worldwide. Its secretome includes proteins, bioactive lipids, and extracellular particles shed in changing composition during development. However, the lipid components of the secretome, including their stage-specific variations and functional significance, remain poorly understood. This study aimed to analyze lipid-containing particles shed by larval and adult stages, and to characterize alterations in lipidomic profiles across the developmental stages. Extracellular nanoparticles (NPs) shed by the parasites, representing a less explored component of the secretome, were isolated using ultracentrifugation and subjected to NP tracking. For a detailed lipidomic and metabolomic analysis of the secretome of different O. dentatum stages, FTIR and LC-MS/MS were applied. The data were compared across life cycle stages to identify developmental and functional variations. The lipidomic analysis revealed distinct profiles for larval and adult stages, with stage-specific lipid classes and metabolites. Shed particles were found to carry a diverse array of lipids, including phospholipids, sphingolipids, and sterols, as well as fatty acids that may be key for interactions with the host, including immune evasion. Comparative analyses demonstrated developmental shifts in lipid composition, highlighting possible adaptations to larval migration, nodule formation, and adult reproduction. This study provides the first comprehensive lipidomic characterization of O. dentatum as a model for gastrointestinal nematodes, unveiling significant stage-specific lipidomic and metabolic adaptations. The detailed analysis of shed nanoparticles as part of the secretome offers new insights into the biology of parasitic nematodes and their interactions with the host environment.