Observations on protective immunity in mice induced by recombinant Schistosoma japonicum Sj14FABP through several adjuvant formulations / 中国血吸虫病防治杂志

Objective To test the protective immunity in mice induced by recombinant Schistosoma japonicum Sj14FABP through several adjuvant formulations. Methods The recombinant Schistosoma japonicum Sj14FABP was prepared by expression in E. coli as a GST fusion protein (rSj14/GST) and used to vaccinate outbred Kunming mice by using complete Freund's adjuvant (FCA)/incomplete Freund's adjuvant (FIA), Bacillus Calmette-Guerin (BCG) and the immunostimulating complex (ISCOM) as adjuvant respectively. Results The purified recombinant protein rSj14/GST was immunogenic in mice, and 34.3% and 36.0% worm reduction rates were obtained in outbred Kunming mice immunized intradermally with BCG adjuvant and immunized subcutaneously with ISCOM adjuvant respectively, compared with non-vaccinated control group. However, intramuscularly vaccination with rSj14/GST in FCA/FIA was not protective, although the high level of IgG antibody was induced. Conclusion Both BCG and ISCOM are suitable adjuvants for rSj14/GST.

Construction and Expression of DNA Vaccine pIRES-Sj97-Sj14-Sj26 and Its Immunogenicity in Mice / 华中科技大学学报（医学）（英德文版）

To find a new preventive strategy for the infection of Schistosoma japonica, plasmid pIRES-Sj97-Sj14-Sj26 that contains fatty binding protein (Sj14), GST (Sj26) and paramyocin (Sj97) that are expressed on the membrane, was constructed. RT-PCR was used to detect the expression of Sj14 mRNA, Sj26 mRNA and Sj97 mRNA in the Hela cells, the indirect immunofluorescent test was employed for the detection of the expression of trans-membrane Sj26 after the plasmid was trans-fected into Hela cells. Fifty BALB/c mice were randomly divided into 5 groups and pIRES-Sj97-Sj14-Sj26 plasmid DNA, pIRES-Sj14-Sj26 plasmid DNA, plRES-Sj26 plasmid DNA,plRES blank vector and normal saline were respectively injected into the quadriceps muscles of thigh.Eight weeks after the immunization the mice were killed and significantly higher level of IgG was detected in the pIRES-Sj97-Sj14-Sj26 group as compared with the plRES blank vector, normal saline and pIRES-Sj26 groups (P<0.01) and the pIRES-Sj14-Sj26(P<0.05). Single splenocyte suspension was prepared to detected the level of IFN-γ by ELISA and the lymphocyte stimulating index (SI) by MTT SI was significantly higher of in the pIRES-Sj97-Sj14-Sj26 group than in other groups (P<0.01), while the IFN-γ, level was significantly higher the pIRES-Sj97-Sj14-Sj26 group than in pIRES blank vector and normal saline groups (P<0.01), but no significant differences were found when compared with pIRES-Sj14-Sj26 and pIRES-Sj26 groups. Flow cytometery showed that the percent-ages of CD4+ and CD8+ T cells were much higher in the pIRES-Sj97-Sj14-Sj26 group (P<0.01,P<0.05). It was concluded that pIRES-Sj97-Sj14-Sj26 vaccine may induce stronger immune response in BALB/c mice.

Construction and Expression of Bivalent Membrane-anchored DNA Vaccine Encoding Sj14FABP and Sj26GST Genes / 华中科技大学学报（医学）（英德文版）

In order to construct a eukaryotic co-expression plasmid containing membrane-anchored Sjcl4FABP and Sjc26GST genes and identify their expression in vitro, Sj14 and Sj26 genes were obtained by RT-PCR with total RNA of Schistosoma japonicum adult worms as the template and cloned into eukaryotic expression plasmid pVAC to construct recombinant plasmids pVAC-Sj14 and pVAC-Sj26. Then a 23 amino-acid signal peptide of human interleukin-2 (IL-2) upstream Sj14 or Sj26 gene and a membrane-anchored sequence containing 32 amino-acids of carboxyl-terminal of human placental alkaline phosphatase (PLAP) downstream were amplified by PCR as the template of plasmid pVAC-Sjl4 or pVAC-Sj26 only to get two gene fragments including Sjl4 gene and Sj26 gene. The two modified genes were altogether cloned into a eukaryotic co-expression plasmid pIRES,resulting in another new recombinant plasmid pIRES-Sj26-Sj 14. The expression of Sj14 and Sj26genes was detected by RT-PCR and indirect immunofluorescent assays (IFA) when the plasmid pIRES-Sj26-Sj 14 was transfected into eukaryotic Hela cells. Restriction enzyme analysis, PCR and sequencing results revealed that the recombinant plasmids pVAC-Sj14, pVAC-Sj26 and pIRES-Sj26-Sj14 were successfully constructed and the expression of modified Sj 14 and Sj26 genes could be detected by RT-PCR and IFA. A bivalent membrane-anchored DNA vaccine encoding Sj14 and Sj26 genes was acquired and expressed proteins were proved to be mostly anchored in cellular membranes.

Immunolocalization of the Signaling Protein l4-3-3 of Schistosoma japonicum / 中国寄生虫学与寄生虫病杂志

Objective To study the localization of the signaling protein 14-3-3 of Schistosoma japonicum (Sj14-3-3)in the parasite. Methods Cercariae were collected from the infected Oncomelania hupensis for the infection of rabbits. Fifteen-day-old schistosomula and adult worms obtained from infected rabbits 15 and 42 days post-infection were used for frozen sections and indirect immunofluorescence staining with monoclonal antibody to rSj14-3-3. Results The results showed that the Sj14-3-3 distributed mainly in the tegument, subtegument, muscle, and parenchyma of both adult worms and 15-day-old schistosomula. Conclusion The wide distribution and large sites of Sj14-3-3 in the parasite were clearly demonstrated, which established a significant clue for further studies of biologic actions and application of 14-3-3 protein.