Definitive host influences the proteomic profile of excretory/secretory products of the trematode Echinostoma caproni.

Background: Echinostoma caproni is an intestinal trematode extensively used as experimental model for the study of factors that determine the course of intestinal helminth infections, since this markedly depends on the host species. Although the host-dependent mechanisms for either chronic establishment or early parasite rejection have been broadly studied, little is known regarding the parasite response against different host environments. Methods: To identify host-dependent differentially expressed proteins, a comparative proteomic analysis of the excretory/secretory products released from E. caproni adults, isolated from hosts displaying different compatibility with this trematode, was performed. Results: A total of 19 differential protein spots were identified (14 overexpressed in mice and 5 overexpressed in rats). The establishment of chronic infections in mice is mainly associated with the overexpression by adult worms of antioxidant and detoxifying enzymes (e.g. glutathione S-transferase, hydroxyacylglutathione hydrolase, thiopurine S-transferase, etc.) and metabolic enzymes like enolase, leucine aminopeptidase or malate dehydrogenase. However, the overexpression of cathepsin L and the structural protein actin observed in worms isolated from rats seems not to be effective for the colonization of the intestinal mucosa of this host. Conclusions: The observed differences suggest that protein expression and/or release is modulated by the local environment generated inside the host and provide useful insights in regards to the resistance mechanisms developed by parasites to ensure their long-term survival. [ABSTRACT FROM AUTHOR]