Novel Hepatic Schistosomula Antigens as Promising Targets for Immunodiagnosis and Immunoprotection of Schistosomiasis japonica.

ABSTRACT

BACKGROUND: Antigens of migrating schistosomula are promising candidates as schistosomiasis vaccine targets, since immune attack on hepatic schistosomula would interrupt the parasites life cycle and reduce egg burden on the host. METHODS: In this study, we report a collection of Schistosoma japonicum schistosomula proteins (SjScPs) that are highly expressed in hepatic schistosomula. The expression characteristics, antigenicity and immune protection of these proteins were studied by western blot, ELISA, immunofluorescence and challenge assays. RESULTS: We found that several of these SjScPs were highly antigenic and could effectively stimulate humoral immune responses in both human and other mammalian hosts. In particular, SjScP25, SjScP37, SjScP41, SjScP80, and SjScP88 showed high potential as biomarkers for schistosomiasis immunodiagnosis. Furthermore, we demonstrated that immunization with several of the recombinant SjScPs were able to protect mice from S japonicum challenge infection, with SjScP25 generating the most protective results. CONCLUSIONS: Our work represents a group of novel schistosome immunogens, which may be promising schistosomiasis japonica diagnosis and vaccine candidates.