[Effects of soluble egg antigen and adult worm antigen of Schistosoma japonicum on differentiation of effector B cells of mice].

OBJECTIVE: To observe the differentiation ability of effector B cells induced by soluble egg antigen (SEA) and soluble adult worm antigen (SWAP) of Schistosoma japonicum. METHODS: The mouse spleen mononuclear cells and CDl9+ B cells sorted by beadg were stimulated by SEA, SWAP and lipopolysaccharide (LPS), respectively. The ratios of CD19+ IL-6+ cells and CD19+ IFN-gamma+ cells were analyzed by flow cytometry after 72 hours. At the same time, the cytokines IL-6 and IFN-gamma levels in the cultured supernatants were detected by ELISA. The mouse was immunized with the mixture of SEA or SWAP or LPS and the incomplete Freund' s adjuvant for three times, respectively. The mouse spleen mononuclear cells were isolated at the seventh day after the last immunization. The ratios of CD19+ IL-6+ cells and CD19 IFN-gama+ cells were analyzed, and the cytokines IL-6 and IFN-gamma+ levels in the culture supernatants were detected. RESULTS: The ratio of CD19 IL-6+ cells in spleen mononuclear cells and splenic B cells was significantly increased in the groups stimulated by SEA and LPS (P < 0.05), and the cytokines IL-6 level in the CD193 cells culture supernatants were significantly increased (P < 0.01). Furthermore, the ratio of CD19+ IL-6+ cells and the cytokines IL-6 level were significantly increased in the SEA immunized group (P < 0.01). SWAP could induce a significantly higher ratio of the CD19+ IFN-gamma+ cells in spleen cells, instead of in splenic CD19+ B cells (P < 0.05). The CD19+ IFN-gamma+ cells and the cytokine IFN-gamma level in the culture supernatants in the SWAP immunized group were significantly higher than those in the SEA and PBS immunized groups (P C 6.01). CONCLUSIONS: SEA preferentially induces the increase of CDl9+ IL-6+ cells in mouse spleen cells; while SWAP preferentially induces the CD19 + IFN-gamma+ cells' production of mouse spleen cells, depending on the effects of other immune cells.

Construction of a plasmid for co-expression of mouse membrane-bound form of IL-15 and RAE-1ε and its biological activity.

Interleukin 15 (IL-15) is a pivotal cytokine for the proliferation and activation of a specific group of immune cells such as natural killer (NK), IFN-producing killer dendritic cells (IKDC) and CD8 T cells. RAE-1ε, the ligand for the activating NKG2D receptor, which also play an important role in the proliferation and activation of NK cells and IKDCs. In this study, a membrane-bound form of IL-15 (termed mb15) encoding sequence and RAE-1ε gene were obtained by SOE-PCR or PCR amplification. The amplified mb15 and RAE-1ε gene were then digested and inserted into the multiple cloning site1 (MCS1) and MCS2 of pVITRO2-mcs vector, respectively. A recombinant eukaryotic expression vector for co-expression of mb15 and RAE-1ε was successfully constructed. After it was transfected to BaF3 cells, the expression of IL-15 and RAE-1ε in recombinant BaF3/mb15/RAE-1ε cells were verified by RT-PCR, western blot and FCM analysis. Furthermore, BaF3/mb15/RAE-1ε cells had the ability of promoting NK cells proliferation and IFN-γ secretion. In conclusion, BaF3/mb15/RAE-1ε cells were successfully constructed, which is very useful for further studies, especially for the expansion and activation of certain subsets of immune cells such as NK cells and IKDCs.