RESUMO
This work was designed to assess the effect of natural infection with S. mansoni cercariae or sensitization to soluble egg antigen [SEA] prior to infection on two strains of mice with different genetic make up [C57BL/6 and BALB/c]. The hepatic pathological and functional changes were evaluated. Splenic cytokine profiles and serum anti-SEA IgG were measured. In response to infection, the granuloma diameter was larger, the eosinophil counts were higher, serum anti SEA-lgG was greater, serum splenic cytokines [IL-2, IFN-gamma, IL-4 and IL-10] were higher in C57BL/6 than BALB/c. In response to SEA-sensitization, greater reduction in granuloma diameter, higher percentage of degenerated ova, normalization of liver function, and elevation of anti-SEA IgG were more obvious in C57BL/6 than BALB/c mice. The reduction of IL-4 relative to the parallel infected group was remarkable in C57BL/6 compared to BALB/c. Other cytokines levels were comparable in both mice strains. It is evident that the immuno-pathological responses in schistosomiasis are different according to the genetic make up of the host