DNA-BASED VACCINATION USING SCHISTOSOMA-JAPONICUM (ASIAN BLOOD-FLUKE)GENES

We have examined the efficacy of nucleic acid vaccination in inducing immunity to the multicellular parasite, Schistosoma japonicum, a trema tode worm responsible for causing schistosomiasis in humans and other mammalian species. A panel of Schistosoma japonicum cDNAs were cloned into eukaryotic expression vectors, injected into animals, and tested for immunogenicity. The cDNAs tested encoded 26- and 28-kDa glutathion e-S-transferases, calreticulin, glyceraldehyde-3-phosphate dehydrogena se, a 22.6 kDa membrane-associated antigen, a 14 kDa fatty-acid bindin g protein, fragments of paramyosin, full-length paramyosin, and a nove l gene comprising the 26 kDa glutathione-S-transferase fused to a frag ment of paramyosin cDNA. The paramyosin gene constructs, including the fusion, were all able to induce anti-paramyosin antibodies; with the fragments of paramyosin these were of the IgG1, IgG2, and IgG2b isotyp es. In contrast, none of the other schistosome cDNAs tested were able to induce detectable antibody responses. The anti-paramyosin antibodie s did not protect mice challenged with cercariae of S. japonicum. (C) 1997 Elsevier Science Ltd.