TAENIA-CRASSICEPS CYSTICERCOSIS - HUMORAL IMMUNE-RESPONSE AND PROTECTION ELICITED BY DNA IMMUNIZATION

The purpose of this study was to evaluate DNA vaccination in cysticerc osis prevention by using a Taenia crassiceps cDNA of a recombinant ant igen (KETc7) that has been reported as protective against murine cysti cercosis. The KETc7 cDNA was cloned into the pcDNA3 plasmid alone or w ith the betaglycan signal peptide sequence (pTc-7 and pTc-sp7, respect ively). Positive expression of the pTc-sp7 product was confirmed by tr ansfection of C33 cells and immunofluorescence using sera of mice infe cted with T. crassiceps. Immunization of mice with 3 injections of pTc -sp7 DNA at the higher dose (200 mu g) was the most effective to induc e antibody with or without bupivacaine. Immunization with pTc-sp7 indu ced protection against challenge with T. crassiceps cysticerci as succ essfully as previously observed with the KETc7 recombinant protein. An tibodies elicited by DNA immunization with pTc-sp7 specifically reacte d with the native protein of 56 kDa previously reported, which is immu nolocalized in the tegument of T. crassiceps cysticerci. The 56-kDa an tigen is also present in Taenia solium oncospheres, cysticerci, and ad ult tissue. The protection induced in DNA-immunized mice and the obser vation that the injected plasmid remains as an episomic form within mu scle cells, encouraged us to continue testing this procedure to preven t T. solium cysticercosis.