Surface and species-specific antigens ofSchistosoma haematobium

Abstract

SUMMARYOf the surface antigens identified by radio-iodination, two-dimensional gel analyses showed no similarities between those ofSchistosoma haematobiumandSchistosoma mansoni, thus providing a basis for the species specificity of these antigens described previously (Simpson, Knight, Hagan, Hodgson, Wilkins & Smithers (1985)Parasitology90, 499–508). The surface antigens ofS. haematobiumwere glycosylated and comprised an acidic polypeptide ofMr17000 as well as a complex set of polypeptides of approximate pI 6–7, which resolved in theMrrange 20000–30000. At least one of the lowerMrforms of this complex is also present in the adult worm. Limited cross-reaction was observed withS. mansoniinfection sera and this may be due to a shared carbohydrate epitope. In contrast, extensive cross-reaction was observed using sera from mice immunized withS. bovis.This pattern parallels the species-specificity of vaccine-induced immunity. Extensive cross-reaction was also observed within cell-free translation products of m-RNA from adult worms ofS. haematobiumandS. mansoniby use of heterologous human infection sera. The few antigens which were species-specific may represent surface antigens.