Downmodulation of Vaccine-Induced Immunity and Protection against the Intracellular Bacterium Francisella tularensis by the Inhibitory Receptor FcγRIIB

Figure 4

Splenocytes from iFt-immunized FcγRIIB KO versus WT mice exhibit enhanced IFN-γ, IL-10, and TNF-α production in response to iFt added ex vivo. WT C57BL/6J and FcγRIIB KO mice were immunized i.n. with 20 μL of PBS (vehicle) or 2 × 10⁷ iFt-organisms in 20 μL of PBS on day 0 and boosted on day 21. (a) Splenocytes were then harvested from individual mice on day 35 and stimulated at a ratio of one iFt per splenocyte. Supernatants were then harvested at the indicated days. (b) FcγRIIB KO and WT mice were immunized and splenocytes were harvested as previously described. Splenocytes were then stimulated at increasing iFt to splenocyte ratios. Supernatants were harvested five days later and analyzed for IFN-γ, (c) IL-10, (d) IL-17A, and (e) TNF-α via CBA assay. A two-way ANOVA and a Bonferroni posttest was performed on the CBA determined sample concentrations to determine statistical significance, and mean and standard deviation is graphed. ; ; .

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