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

Figure 5

Levels of proinflammatory cytokines in the lungs of iFt-immunized FcγRIIB KO versus WT mice were reduced 5 days after challenge. 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. On day 35 mice were given a sublethal challenge i.n. with approximately 0.4 × LD₅₀. Five days after challenge lung tissue was collected, homogenized, and centrifuged and supernatants were collected. Luminex assay was performed on tissue supernatants to determine in vivo cytokine levels. Each symbol represents a single mouse. A value of 0.1 was added to the average cytokine concentration to correct for heteroscedasticity. A one-way ANOVA along with a Tukey’s multiple comparison test was performed on the log of the average cytokine concentration of lung and BALF samples from individual mice to determine statistical significance, and median and interquartile range is graphed. .

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