FIG. 5.

IL-4 production by splenocytes from mice upon in vitro stimulation with different antigens. Culturing and stimulation of splenocytes were performed as described in the legend to Fig. 4. After 4 days, the cultured cells were restimulated with PMA-ionophore for 16 h, and supernatants were collected and tested for IL-4 production by a sandwich ELISA. Addition of CpG-ODN to the vaccination protocols significantly decreased IL-4 production compared to that with the protocols without CpG-ODN (P < 0.01). Stimulation with purified Brucella Cu,Zn SOD produced significantly more IL-4 in the splenocytes of mice immunized with strain 49237SOD alone than in the splenocytes of mice immunized with strain 49237SOD plus CpG-ODN (P < 0.01).