Intraperitoneal injection of echinostome antigens confers resistance to schistosomal infection in murine model

ABSTRACT

The effect of immunization protocol against S. mansoni infection with purified metacercarial antigen from E. liel alone or combined with BCG on resistance to S. mansoni infection and associated immunoparasitological changes in murine experimental model was studied. The results revealed highly significant reduction in worm burden and hepatic and intestinal tissue egg loads were observed on comparing the two immunized groups [purified metacercarial antigen alone or purified metacercarial antigen plus BCG] with the infected control group [p> 0.001]. Moreover the greatest reduction in the worm burden was observed in group injected with purified metacercarial antigen pluse BCG. A significant reduction [p> 0.001] was observed in granuloma diameter in the two immunized groups relative to infected control. However, the greatest reduction in granuloma diameter was noticed in group II [purified metacercarial antigen pluse BCG]. No significant difference was observed in granuloma diameter berween the two immunized groups. Anti-SEA serum specific immunoglobulins in group I and group II showed a significant increase in both IgG and IgM [p> 0.05] compared to the infected control group. A higher significant increase was found in the specific immunoglobulin isotype IgGI [p> 0.001] in both group I and II compared to infected control group. In conclusion, our findings showed that multiple intraperitoneal adminestration of purified metacercarial antigen induce highly significant reduction in worm burden, hepatic and intestinal tissue egg loads and granuloma size 8 weeks post infection