RESUMEN
The aim of this research was to study the immunoprotections of Schistosoma japonicum (S. japonicum) DNA vaccines SjRPS4 and SjRPL7 in mice. Fourty Kunming mice were randomly divided into 4 groups (A, B, C and D), and the pcDNA3.0/SjRPS4 and pcDNA3.0/SjRPL7 plasmid DNA vaccines were prepared for experiment. Mice in group A were intramuscularly injected with 100μL normal saline, whereas mice in group B were injected with 100 (g naked plasmid pcDNA3.0 into the quadriceps. Mice in groups C and D were injected with 100μg/100μL eukaryotic recombinant plasmids pcDNA3.0/SjRPS4 and pcDNA3.0/SjRPL7 into the hind leg muscles respectively. The initial injections were followed by two sets of boosters at 2 weeks intervals. In addition, levels of the specific antibodies were detected 2 weeks after the last immunization and all mice were percutaneously infected with 20( 1) S. japonicum cercariae on abdomen. Fourty-two days after the infection, all mice were killed to detect the worm reduction rate and the egg reduction rate. Significant differences of worm burden reduction rates, LEPG reduction rates, IEPG reduction rates and intrauterine eggs reduction rates were observed in both test group (group C and D), comparing with the control groups (group A and B). Results indicated that the DNA vaccines of pcDNA3.0/SjRPS4 and pcDNA3.0/SjRPL7 could induce strong protective immunity against S. japonicum in mice.