Proteomic analysis of the tegument and excretory-secretory products of adult Schistosoma bovis worms

Schistosoma bovis is a ruminant pathogen that is poorly known at a molecular level. With an aim of identifying the parasite proteins involved in host-parasite interplay, we studied two protein extracts that contain, respectively, the proteins excreted/secreted by the adult worm (ES) and the tegumental proteins exposed to the host (TG). The 2-DE, 2-D immunoblot and MS were employed to separate and identify the antigenic proteins and the most abundant non-antigenic proteins in each extract. There were some 400 and 600 spots detected in the ES and the TG extracts, respectively. Ninety-six spots were subjected to MS analysis and 64 of them were identified. Overall, we identified 18 S. bovis proteins located at the host-parasite interface, 16 of which have not been identified previously in this parasite, and one of which -lysozyme- has never been reported in a Schistosoma species. Of the proteins identified, at least 4 can counteract host defence mechanisms. The other proteins are also likely to play some role in the host-parasite relationships. Therefore, studies in grater depth on all these proteins will provide a better understanding of how this parasite interacts with its host and new strategies for anti-schistosome drug or vaccine design.