[Prediction of T-cell epitopes from schistosoma japonicum 28 kDa glutathione-S-transferase and identification of their Th1 type T-cell epitopes].

Aim: To predict T-cell epitopes of recombinant schistosoma japonicum 28 kDa glutathione-S-transferase(GST) with software and identify the Th1 type T-cell epitopes by experiments.
Methods: T-cell epitopes of recombinant schistosoma japonicum 28kDa GST were predicted with software and several epitopic candidates were screened from them according to their scores. Some of the epitopic candidates were synthesized and the other epitope peptides fused with thioredoxin(Trx) were expressed in E.coli BL21(DE3) and purified by Ni(+) column affinity chromatography. C57BL/6 (H-2(b)) mice's were immunized via peritoneal infection with ultraviolet ray irradiated-cercariae and then boosted with recombinant schistosoma japonicum 28 kDa GST. The immunized mice splenocytes were prepared, cultured and stimulated with synthesized epitope peptides and epitope peptide fusion proteins, respectively. Stimulation activity of synthesized epitope peptides and epitope peptides fusion proteins were assayed by lymphocyte proliferation assay. Levels of IFN-gamma and IL-2 were measured by ELISA. CD4(+) T cells and T cells secreting IFN-gamma and IL-4 were detected by flow cytometry.
Results: Epitope P6(73-86aa) among 9 epitopic candidates could generate the strongest stimulation effect on splenocytes, stimulate secretion of higher levels of IFN-gamma and IL-2, and induce more IFN-gamma(+) and IL-4 (+) T cells.
Conclusion: The recombinant 28 kDa GST possesses functional Th1 type T-cell epitope.