Vaccination of goats with 31 kDa and 32 kDa Schistosoma japonicum antigens by DNA priming and protein boosting.

Two Schistosoma japonicum vaccine candidate antigens Sj 31 and Sj 32, which have shown particular promise to induce protective immunity in mice, were used to immunize goats by using a DNA priming-protein boosting strategy in present work. DNA vaccine formulations of the two antigens (VRSj31 and VRSj32) were produced and injected intramuscularly twice at a 2-week interval and then recombinant proteins (rSj31 and rSj32) together with Freund Complete Adjuvant (FCA) were used to boost the goats. The experiment was repeated in different batche cercariae.

Identification and characterization of peptides mimicking the epitopes of metalloprotease of Schistosoma japonicum.

In an attempt to isolate and characterize peptides mimicking epitopes of metalloprotease and explore their immunological protection against Schistosoma japonicum (S. japonicum), polyclonal anti-metalloprotease sera was prepared to screen a 12-mer random peptide library to isolate phages binding specially to antisera IgG. Then, phage ELISA, animal immunization, DNA sequencing, Western blotting and enzymatic activity neutralizing analysis were used to characterize the selected phage clones.

[Boost effect of recombinant IL-4 on protection of Schistosoma japonicum cathepsin B DNA vaccine in mice against the parasite].

Objective: To investigate the enhancement effect of IL-4 expression plasmid on cathepsin B DNA vaccine of Schistosoma japonicum (Sj) in mice.

Methods: The recombinant IL-4 plasmid constructed by cloning PCR amplified product of murine IL-4 gene into eukaryotic expression vector pcDNA3.1 was co-injected intramuscularly with Sj cathepsin B expression plasmid DNA to mice as the test group.

[Cloning and characterization of new genes of Schistosoma japonicum].

Objective: To clone and characterize new genes of Schistosoma japonicum, Sj, and to provide efficient vaccine candidates.

Methods: Sj adult cDNA library was screened with rabbit sera raised against male worm soluble antigen. The inserted cDNA fragments from the positively selected clones were amplified with PCR and further sequenced, as well as characterized through internet NCBI GenBank software.

Schistosoma japonicum: isolation and identification of peptides mimicking ferritin epitopes from phage display library.

In an attempt to isolate and identify the antigenic epitopes on ferritin of Schistosoma japonicum (SjFer) and to test their protective potentiality against Schistosoma japonicum (S.j), polyclonal antisera against SjFer was prepared to screen a 12-mer random peptide library. Three rounds of biopanning were performed and resulted in an enrichment.

[Study on the subcloning, expression and immunoprotection with Schistosoma japonicum CAI gene].

Objective: To subclone and express the new gene of Schistosoma japonicum (Sj) CAI and evaluate the immunoprotective effect of the recombinant molecule.

Methods: The cDNA of SjCAI gene was subcloned into expression vector pGEX-5X-3 to form recombinants which were then used to transform to E. coli strain ER 2566.

[Immunoscreening of Schistosoma japonicum adult worm cDNA library with sera vaccinated with cercaria antigen and analysis of novel genes].

Objective: To explore antigens possessing common immunogenicity with Schistosoma japonicum (Sj) cercariae antigens, and to find out new candidate antigens for schistosomiasis diagnosis and vaccine.

Methods: Sj adult cDNA library was screened using sera from rabbits vaccinated with Sj cercariae antigen, the inserts of positive clones were amplified by PCR, all positive clones were sequenced and the data were analysed using Nucleotide BLAST software of NCBI and Expert Protein Analysis System of Swiss Institute of Bioinformatics.

Results: Thirteen positive clones were obtained after three rounds of immunoscreening, and all amplified by PCR.