Immunolocalization of B7-z and CD28 costimulatory molecules in schistosomal soluble egg antigra -induced granulomatous hyporesponsiveness

In this work, the changes in expression of the costimulatory molecules [B7-2/CD28] were studied at 6, 8 and 16 weeks p.i. on immuno-inflammatory cells of livers in S. mansoni-infected and SEA-sensitized mice model by immunohistochemistry. Both B7-2 and CD28 were only expressed positively at 6 weeks p.i. in both groups with significantly lower cell counts in SEA group compared to infected control group. The distribution of B7-2 was concentrated towards the periphery of the granulomas, while that of CD28 was homogeneously distributed all through the granulomas. The present data showed that repeated i.v. injection of SEA before infection resulted in the drop of B7-2/CD28 to lower levels than its expected natural course. This drop may explain the decrease of host immunopathological reaction to S. mansoni eggs in the SEA group than infected control group

Implication of genetic make-up on immunopathological responses in murine schistosomiasis mansoni

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