[Immunization of mice with native tropomyosins from Schistosoma japonicum and Oncomelania hupensis].

AIM

To study the protection against cercariae challenge in mice immunized with native tropomyosin (TM) antigens from Schistosoma japonicum (Chinese strain) and Oncomelania hupensis.

METHODS

The native TM antigens were extracted from adult worms of S. japonicum (SjcTM) and head-pad of O. hupensis (OhTM), the purity and the molecular weight of these antigens were analysed by SDS-PAGE. Each C57BL/6 female mouse was immunized subcutaneously by injection of 5 micrograms SjcTM or 30 micrograms OhTM emulsified in an equal volume of Freuds adjuvant for three times. Control mice were injected only with adjuvant. All the mice were artificially challenged with cercariae of S. japonicum at five days after final injection. Six weeks after challenge, the mice were perfused, the worms and the eggs collected from the livers and the intestines of mice were counted.

RESULTS

The prepared SjcTM and OhTM antigens were shown to be pure, the molecular weight being around 40 kDa. Compared with the control group, the worm reduction rates of SjcTM group and OhTM group were 21.1% and 28.2%, respectively; the egg reduction rates per worm pair in the tissues were 20.1% and 52.2% (liver), 32.8% and 28.1% (intestine), respectively; the matured egg reduction rates in the tissues were 25.9% and 46.8% (liver), 39.7% and 66.8%, respectively.

CONCLUSION

SjcTM and OhTM antigens can be served as new candidates of vaccine against schistosomiasis japonica.