Demonstration of species-specific and cross-reactive components of the adult microsomal antigens from Schistosoma mansoni and S. japonicum (MAMA and JAMA).

Analysis of human serum reactivities to the Schistosoma mansoni adult microsomal antigens (MAMA) showed that S. japonicum and S. haematobium infection sera, as a rule, did not react as well to MAMA as did the homologous S. mansoni infection sera. The degree of species specificity, although not absolute, was quite pronounced. Purification of the corresponding microsomal antigens from S. japonicum adults (JAMA) and subsequent assays with both homologous and heterologous infection sera show a distinct and reciprocating species specificity between S. mansoni and S. japonicum microsomal antigens. The specificities of these antigens were quantitated by k-ELISA. Qualitative analysis of active antigenic components for both JAMA and MAMA involved assay by the "Western blot" or enzyme-linked immunoelectrotransfer blot (EITB). The EITB patterns of both antigens, after resolution by SDS-PAGE, show species-specific reactive bands at the 16,000 to 35,000 m.w. region. S. japonicum-specific antigens are located at the 18,000 to 35,000 m.w. region whereas S. mansoni-specific antigens were associated with m.w. components of 16,000 to 29,000. High m.w. antigen components (greater than 40,000) of both JAMA and MAMA are recognized by both heterologous and homologous infection sera and are thus not species specific. The demonstration of the clear separation of species-specific antigen bands of JAMA and MAMA by physical size offers a unique opportunity to isolate and characterize the species specificities of antibody-antigen reactions in these parasitic infections.