DNA vaccine pCD-Sj32 and its efficacy of protective immunity against infection of Schistosoma japonicum

OBJECTIVE: To study protective immunity afforded by murine immunization with DNA vaccine of Schistosoma japonicum (S. japonicum) as measured by reduction in worm burden and host antibody, cytokines. METHODS: DNA vaccine pCD-Sj32 was constructed, identified and expressed. pCD-Sj32 could induce substantial protective immunity against infection of S. japonicum in BALB/c mice. The best efficacy can be produced with one injection of 100 micrograms DNA into the quadriceps muscle, combined with challenge for 8 weeks after immunization. T lymphocyte subsets of CD8+, IL-2. TNF and IFN-gamma of experimental animal could play important roles in regulating immune functions of schistosomiasis. RESULTS: High titre of specific antibody IgG could be induced by vaccinated with pCD-Sj32, and antibody can mediate macrophage to produce ADCC effects in vitro. CONCLUSION: pCD-Sj32 may represent a new approach to developing subunit vaccine.