The Adjuvant Effect of IL-12 on Protective Immunity of Schistosoma japonicum Fatty Acid Binding Protein (Sj14FABP) / 中国寄生虫学与寄生虫病杂志

ABSTRACT

Objective To study the immune protection of Schistosoma japonicum fatty acid binding protein (Sj14FABP) DNA vaccine enhanced by IL-12. Methods The recombinant plasmids pVIVO2-Sj14FABP and pVIVO2-IL12-Sj14FABP were constructed respectively, and were prepared on a large scale after identification. 48 male BALB/c mice were divided into 4 groups randomly. In group A, B, C, and D, each mouse was injected intramuscularly with 100 ?l 0.9% NaCl, 100?g pVIVO2, 100?g pVIVO2-Sj14FABP and 100 ?g pVIVO2-IL12-Sj14FABP respectively. 30 days after immunization each mouse was challenged with 40?2 cercariae of S. japonicum. On day 45 after challenge, all mice were sacrificed to count the number of recovered adult worms and the hepatic eggs. Sera from mice were used to detect IgG antibody. The production of IL-2, IL-4 and IFN-? in the supernatant of spleen cells was observed by means of sandwich ABC-ELISA. Results The recombinant plasmids pVIVO2-Sj14FABP and pVIVO2-IL12-Sj14FABP were constructed. The worm reduction rate in group C and D was 24.11% and 39.4%, as well as liver egg reduction rate of 27.2% and 32.8% respectively. The level of IL-2 and IFN-? in group D increased significantly, while IL-4 secretion decreased(P0.05). Conclusion Sj14FABP DNA vaccine induces partial protective immunity in BALB/c mice. IL-12 drives the immune response toward a Th1 direction, and enhances the protective immune effect of the vaccine. [