Immunologically cross-reactive molecules of Schistosoma japonicum and Lumbricus terrestris were identified by
antibodies derived from human and rodent sera. Pooled
IgG from
schistosomiasis patients but not uninfected individuals bound multiple
antigens of identical molecular weight in both soluble S. japonicum worm
antigen preparations (SWAP) and soluble earthworm preparations (SEWP). These
antigens had molecular weights corresponding to 18, 40, 62, 64, 74, 97, and > 110 kDa. Three of these
antigens of 74, 97 and > 110 kDa were immuno-affinity purified using
antibodies derived from
schistosomiasis patients' sera. Vaccination of mice with SEWP produced murine
antibodies which bound parasite molecules of 40, 74, 97, and > 110 kDa and induced 36% protection from S. japonicum
infection (P < 0.05). Antibody production to S. japonicum
paramyosin, a molecule previously shown to induce protection from schistosome
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
schistosomiasis.