Suppression of Schistosoma bovis egg production in cattle by vaccination with either glutathione S‐transferase or keyhole limpet haemocyanin

Abstract

Two of the antigens which have shown vaccine potential in animal experiments against Schistosoma mansoni are glutathione-S-transferase (GST) and GP38, protective epitopes of which are shared with keyhole limpet haemocyanin (KLH). We therefore tested S. bovis GST and KLH for vaccine efficacy against S. bovis in the natural Zebu cattle host. In a preliminary experiment three vaccinations with a total of 1.39 mg of native GSTs of S. bovis induced specific antibody at the time of challenge as detected by Western blotting and ELISA and mean faecal egg counts between weeks 6-10 post-challenge were reduced by 56.4 to 82.5% compared to non-vaccinated controls. Mean adult worm recoveries and tissue egg densities in large intestine and liver samples were also reduced in the vaccinated group, but these differences were not statistically significant. In a subsequent experiment one group of calves was vaccinated with a similar schedule to that used above; a second group of calves was given only two injections of GST (total 0.48 mg protein); a third group of calves was vaccinated twice with a total of 2.0 mg KLH in PBS. All three vaccination schedules induced specific antibody. Both GST vaccination schedules induced significant reductions in faecal egg counts compared to non-vaccinated controls and in this experiment tissue egg densities were also significantly reduced. A striking finding, however, was that adult worm counts were not reduced by vaccination. An essentially similar outcome resulted from KLH vaccination, since there were significant reductions in faecal and tissue egg counts in the absence of a reduction in adult worm numbers.(ABSTRACT TRUNCATED AT 250 WORDS)

TheTrypanosoma cruziTc52-Released Protein Induces Human Dendritic Cell Maturation, Signals Via Toll-Like Receptor 2, and Confers Protection Against Lethal Infection

“…For instance, the Schistosoma mansoni GST (28 kDa) is a promising vaccine candidate in human schistosomiasis (45). Immunization of cattle with Schistosoma bovis GST induced a decreased number of S. bovis, eggs which are believed to be the cause of pathology (46). In addition, a significant degree of protection against fascioliasis could be achieved by immunization of sheep with F. hepatica GST (47).…”

Specific Antibody Responses to Three Schistosome-Related Carbohydrate Structures in Recently Exposed Immigrants and Established Residents in an Area ofSchistosoma mansoniEndemicity

“…However, others have reported that the KLH-ELISA was not useful for serodiagnosis of travelers and for mild schistosome infections (27) and that the anti-KLH responses were similar in acutely and in chronically infected patients (13). Vaccination with KLH resulted in partial protection of calves against infection with S. bovis and sheep against infection with S. japonicum (3,20). Kantelhardt and colleagues suggested recently that the part of the FLDN structure (Fuc␣1-3GalNAc) that is shared by schistosome glycans and KLH provides a basis for the potential of KLH in schistosomiasis vaccination and serodiagnosis (10).…”

Glutathione S-transferases of 28kDa as major vaccine candidates against schistosomiasis

“…The level of protection conferred against infection varies from a mean of 50-70% in rats to 40-50% in mice and 40% in baboons. The relevance of our choice for the 28GST as vaccine candidate has been strengthened by vaccination experiments performed in Sudan against cattle schistosomiasis due to S. bovis (Bouchara et al 1993).…”

“…The experiments in baboons using recombinant Sm28GST highlighted a different protective effect of immunization, which until recently had not been demonstrated with any other antigen. This effect was a reduction in the fecundity of female worms reflected in a reduced excretion of eggs by immunized animals, and a reduction in tissue egg loads in mice immunized with Sm28GST and challenged with S. mansoni (Boulanger et al 1991) and in cattle immunized with native Sb28GST and infected with S. bovis (Bouchara et al 1993). This particular protective effect of the immune response could be related to the inhibition of the GST enzymatic activity by antibodies (Xu et al 1991, which is vital to the survival of the parasite in the definitive host (Mitchell 1989).…”