FIG. 8.
Production of cytokines in stimulated spleen cells from vjbR::Tn5-vaccinated BALB/c mice. Mice were vaccinated with 105 CFU of either nonencapsulated B. melitensis vjbR::Tn5 mutant, encapsulated B. melitensis vjbR::Tn5/alginate mutant, encapsulated B. melitensis vjbR::Tn5 mutant with VpB in the core (vjbR::Tn5/alginate/VpBcore), or encapsulated B. melitensis vjbR::Tn5 mutant with VpB in the shell (vjbR::Tn5/alginate/VpBshell). Control groups received empty capsules or MOPS. At 31 weeks postvaccination, mice were euthanized, and splenocytes were harvested and stimulated with heat-inactivated B. melitensis 16M or medium alone as a control. IFN-γ (A) and IL-12p70 (B) production (pg/ml) was detected after 72 h of stimulation by using a multiplex suspension array system (Bioplex). Cytokine production was expressed as the mean cytokine concentration ± SEM for each group of mice. Differences in colonization between the nonencapsulated and encapsulated groups were determined by ANOVA followed by Tukey's honestly significant difference posttest comparing all groups to each other. *, P < 0.05, and **, P < 0.01, with lowercase letters indicating the groups as follows: a, MOPS group; b, alginate group; c, vjb::Tn5/alginate group, d, vjb::Tn5/alginate/VpB shell group; e, vjb::Tn5/alginate/VpB core group; and f, nonencapsulated vjb::Tn5 group.