In this study, adults and plerocercoids of S. mansoni were cultivated in vitro to systematically analyze the components of the excretory–secretory proteins (ESPs) of Spirometra mansoni. Afterwards, the differentially expressed proteins (DEPs) were identified and protein components were examined using the Data Independent Acquisition (DIA) mode. A total of 944 proteins were identified, including 580 plerocercoid-specific proteins, whereas no specific proteins were found in adults. Quantitative analysis revealed that 607 proteins were significantly differentially expressed, with 390 upregulated in the plerocercoid group, and 217 upregulated in the adult group. Gene Ontology functional annotation revealed that the upregulated proteins in the plerocercoid group were significantly enriched in functions such as nitrogen compound metabolism, proteasome core complexes, and ion binding. Kyoto Encyclopedia of Genes and Genomes pathway enrichment revealed that the DEPs were strongly correlated with signal transduction, signal transportation, and catabolism pathways. Moreover, metabolic network analysis revealed that key pathways included the pentose phosphate pathway and glycolysis/gluconeogenesis. In addition, indirect ELISA revealed that immunization of mice with ESPs induced a Th1/Th2 mixed immune response, dominated by a Th1 response. Cytokine detection further verified that ESPs had good immunogenicity, and could activate both humoral and cellular immune responses. This study revealed, for the first time, the differential expression profile of ESPs between adults and plerocercoids of S. mansoni. These findings offer a potential reference for the diagnosis and prevention of sparganosis.
Gao et al. (Wed,) studied this question.