[Studies on the protective effect of the mutant of Sj23 DNA vaccine against schistosomiasis].

Objective: To investigate the protective immunity of the vaccine against schistosomiasis, a mutant of Mr 23 000 membrane protein DNA (Sj23DNA) without the homologous sequence of ME491.

Methods: The mutant of Sj23 DNA with no homologous sequence of ME491 on the cell membrane of human melanoma was obtained by overlap PCR. The mutant was transfected into human embryonic kidney cells of the line HEK293.

Studies on the protective immunity of Schistosoma japonicum bivalent DNA vaccine encoding Sj23 and Sj14.

In order to explore the high performance bivalent DNA vaccine of Schistosoma japonicum, the fatty-acid-binding protein (Sj14) and the 23 kDa transmembrane protein (Sj23) two proteins were selected to construct the DNA-based vaccine. It was successful to construct a bivalent DNA vaccine using three strategies: the co-expression of two genes, a fusion gene expression and two kinds of plasmids in combination (cocktail vaccine). The bivalent DNA was proven to express well in vitro and in vivo by indirect immunofluorescence test (IIF) and reverse transcriptase-polymerase chain reaction (RT-PCR).