Proteomics analysis of excretory-secretory proteins in mixed-sex adult stage Toxocara canis

Introduction Toxocara canis is a prevalent zoonotic nematode responsible for toxocariasis in humans and animals. To better understand the molecular mechanisms underlying parasite persistence and host interaction, this study provides the first comprehensive proteomic characterization of excretory-secretory products (ESPs) from adult T. canis . Methods ESPs were collected from mixed-sex adult worms and analyzed via LC-MS/MS. Results A total of 468 proteins were identified. The secretome was dominated by highly abundant Toxocara excretory-secretory (TES-26) phosphatidylethanolamine-binding proteins, C-type lectins (Collectin-12), and superoxide dismutases (SOD), that accounted for 34 ESPs and 49.3% of total detected protein. Functional enrichment revealed a significant presence of classical secretion signal peptides, as well as proteins associated with the exosome pathway, indicating the utilization of non-classical secretion mechanisms. Comparative orthology analysis against the phylogenetically related (Clade III) nematodes Ascaris suum and more distant (Clade V) Ancylostoma ceylanicum demonstrated a strong enrichment for species-specific ESPs, as well as a subset of highly conserved ESPs across species. Discussion These findings establish a foundational proteomic framework that enhances our understanding of T. canis biology and identifies promising targets for highly specific diagnostics and rational vaccine development.