Characterizing excretory-secretory products proteome across larval development stages in Ascaris suum

Ascaris spp are the most common parasitic helminth infection in the world. After oral ingestion of eggs, Ascaris larvae undergo a larval migratory cycle through the host. During the migratory cycle larvae release proteins known as Excretory-secretory (ES) product that are thought to aid in development and migration. This study characterizes the excretory-secretory (ES) proteome of different Ascaris larval stages (L3-egg, L3-lung, L3-trachea) to identify interventional targets to prevent Ascaris-induced morbidity. Stage-specific larvae were isolated, cultured in vitro and ES-product was collected. Third-stage Ascaris larvae (L3) were isolated from embryonated eggs (L3-egg), from Balb/c mice lungs infected with Ascaris at day 8 post infection (L3-lungs) and isolated from Balb/c mice trachea infected with Ascaris at day 12 post infection (L3-trachea). Proteomic analysis was conducted using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The analysis encompassed peptide identification, scoring, and quantification against an organism-specific database, with subsequent quality control, correlation assessment, and differential abundance determination. A total of 58 unique proteins were identified in the ES products. Fourteen proteins were common across all stages, while others were stage-specific. Principal component analysis revealed distinct protein profiles for each stage. Gene ontology analysis indicated stage-specific enrichment of specific protein classes, such as nuclear proteins in L3-egg ES products and metabolic enzymes in L3-lung and L3-trachea ES products. This study revealed stage-specific differences in the composition of Ascaris ES products. Further investigation into the functional roles of these proteins and their interactions with host immune cells is crucial for developing novel therapeutic strategies to prevent Ascaris larval migration.