Induction of protective immunity against S. mansoni in mice vaccinated with Sm10-DLC

Sm10-DLC, a 10-kDa dynein light chain protein identified as a strong T cell immunogen in a large number of subjects sensitized by natural infections, may be of interest for vaccination. To assess the vaccine potential of Sm10 we carried out immunization trials in CBA/J mice using recombinant Sm10 (rSm10) expressed in E. coli and tested its capacity to induce protection against a challenge infection. With one rSm10 preparation injected intramuscularly in Freund's adjuvant, a significant reduction in worm burden (27% reduction) was obtained in two independent experiments. We have not obtained protection with other adjuvants, in particular with alum. In addition, a negative correlation was observed between the antibody response and the worm burden reduction. These results suggest that rSm10 injected with Freund's adjuvant was able to induce a protective immunity against Schistosoma mansoni.