NAKED DNA VACCINE FOR SCHISTOSOMIASIS

Abstract

fhe DNA-based vaccine technology is a promising new tool in the development of vaccines and has been shown to confer immunity against different infectious diseases including parasitic infections. In this study we evaluated the feasibility of using a nucleic acid vaccine to induce protective immune responses to the Schistosoma mansoni fimbrin like protein (Smfim}. Swiss albino mice were immunized by intramuscularly injection with pcDNA plasmid construct encoding Smfim (Smfim-pcDNA), under the control of CMV promoter. ELISA analysis indicated that mice immunized with Smfim-pcDNA generated specific antibodies for Smfim. The reduction in worm burden provided significant levels of protection (57%) against challenge infection. Immunization with Smfim-pcDNA led to an anti-fecundity effect; as female worms of a challenge infection produced 70% less eggs than those growing in naive mice. The histopathological study of the immunized mice liver revealed a significant reduction in the size of granuloma compared with control. The results suggest that Smfim-pcDNA may represent a new approach to developing DNA vaccine.