Mona A.M. El Gawish and Mervat Abdel Fattah Moawad
Protective immunity against Schistosoma mansoni
infection correlates with increased levels of IgE and
blood eosinophilia which are considered as markers of
anti-parasitic cell-mediated immunity. IL-5 participates as well in the
induction and regulation of IgE and eosinophilia, consequently in the development of acquired
immunity. Swiss Webster female mice were subcutaneously injected with either 50
µg of g-irradiated cercarial
homogenate (400 Gy) twice weekly for three weeks
alone or plus a single dose of IL-12 (0.8 ng/Kg). The
efficiency of immunization regimens were assessed 45 days post infection with
100 live cercariae/mouse by the number of worm burden, ova count, production of
IL-5, eosinophils, and IgE
levels in the vaccinated groups compared with the non-immunized group. The
results demonstrated a significant reduction of ova count in the livers of
vaccinated groups (57.19 and 40.13
%) and worm couples compared with the non –immunized group. Furthermore, a
decrease of IL-5 level as well as eosinopenia was
recorded in both vaccinated groups. Scanning electron microscope (SEM) of adult worms recovered from the immunized groups revealed marked damage on the tegumental
surface in males rather than females as well as constrictions and intensive
corrugation of intertubercles.