[Dynamic changes of proliferation, subsets and apoptosis of splenocytes from BALB/c mice immunized with recombinant Bb(pGEX-Sj26GST-Sj32) vaccine against Schistosoma japonicum].

OBJECTIVE: To study the dynamic change of proliferation, subsets and apoptosis of splenocytes of BALB/c mice immunized with recombinant Bb(pGEX-Sj26GST-Sj32) vaccine of Schistosoma japonicum. METHODS: A total of 96 BALB/c mice were randomly divided into 2 groups (n=48 per group) and immunized with the recombinant vaccine orally (PO group) and intranasally (IN group) respectively. Then autopsies were made in 4 mice of each group 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 weeks after immunization to separate splenocytes. After being cultured under the activation of SjAWA, the splenocytes were observed in the proliferative response using the MTT assay. The stock (non-stimulation) and concanavalin A (ConA) activation were used as controls; The proportions of CD4(+) and CD8(+) T cells were determined by flow cytometry (FCM); Splenocytes cultured under the activation of ConA were collected to detect the apoptotic rates of splenocytes by FCM, with the stock group as a control. RESULTS: The level of splenocyte proliferation in PO group peaked on week 4 after immunization, while the level in IN group did so on week 12. The level of CD4(+) T cell subsets in PO group reached the highest on week 4 after immunization, while the level in IN group did so on week 12. The level of CD8(+) T cell subsets in PO group rose to the top on week 10 after immunization, while the level in IN group did so on week 6. The apoptotic rate of splenocytes in PO group was the highest on week 6 after immunization, while the rate in IN group did so on week 12. CONCLUSION: The recombinant Bb(pGEX- Sj26GST-Sj32) vaccine could cause proliferation of splenocytes, induce immune protection to the host by up-regulating CD4(+) and CD8(+) T cells and inhibit the apoptosis of splenocytes from mice.