Egg-hatching inhibition in mice immunized with recombinant Schistosoma bovis 28 kDa glutathione S-transferase

The capacity of a recombinant glutathione S-transferase from Schistosoma bo vis (rSb 28GST) to protect BALB/c mice against homologous and heterologous infections with, respectively, S. bovis or Schistosoma mansoni has been stu died. Two injections of the rSb 28GST and an intravenous boost resulted in a marked specific IgG response on the day of experimental challenge with S. bovis or S. mansoni cercariae. immunization of BALB/c mice led to a reduct ion in egg maturation and egg viability after infection with S. bovis or S. mansoni. Adult worm recoveries after an S. bovis challenge infection and t issue egg densities (intestine and liver) in S. mansoni challenge infection were also reduced in the immunized groups, but these differences were not statistically significant. No association between in vitro inhibition of GS T enzymatic activity induced by immunized mouse sera and worm burden reduct ion was recorded. The analysis of the immune response, on the day of perfus ion, showed the production of immunoglobulin (Ig)G(1), IgG(2a) and IgG(2b) specific antibodies and the production of interleukin (IL)-4 and IL-5 by sp leen cells after rSb 28GST stimulation. These data suggest that rSb 28GST i mmunization induces a moderate effect upon egg maturation and egg hatching, suggesting the involvement of similar mechanisms of action and common, but not exclusive, targets during S. bovis and S. mansoni infections. As a con sequence, immunization with rSb 28GST may prove useful in affecting the pat hology and transmission of African schistosomes.