INDUCTION OF PROTECTIVE IMMUNITY TO SCHISTOSOMIASIS WITH IMMUNOLOGICALLY CROSS-REACTIVE LUMBRICUS MOLECULES

Immunologically cross-reactive molecules of Schistosoma japonicum and Lumbricus terrestris were identified by antibodies derived from human and rodent sera. Pooled Ige from schistosomiasis patients but not unin fected individuals bound multiple antigens of identical molecular weig ht in both soluble S. japonicum worm antigen preparations (SWAP) and s oluble earthworm preparations (SEWP). These antigens had molecular wei ghts corresponding to 18, 40, 62, 64, 74, 97, and >110 kDa. Three of t hese antigens of 74, 97 and >110 kDa were immuno-affinity purified usi ng antibodies derived from schistosomiasis patients' sera. Vaccination of mice with SEWP produced murine antibodies which bound parasite mol ecules of 40, 74, 97, and >110 kDa and induced 36% protection from S.j aponicum infection (P<0.05). Antibody production to S. japonicum param yosin, a molecule previously shown to induce protection from schistoso me infection, was prominently expressed in the protected murine immune sera. The study shows that Lumbricus sp. represent a potential source for paramyosin and other candidate vaccine molecules for schistosomia sis.