Activation with IFN-γ in the presence and absence of GM-CSF enhances the pro-inflammatory cytokine profile of macrophages in response to live <i>P</i>. <i>aeruginosa</i>.

<p>Macrophages were plated in X-Vivo 15, treated with IFN-γ in the presence and absence of GM-CSF for 48 h and infected with PAO1-L for 4 h. <b>A</b>. Macrophage activation upregulated the production of TNF-α and IL-6 and downregulated IL-10 production in response to PAO1-L infection. Negligible to no production of these cytokines was seen in uninfected macrophages under all activation conditions. <b>B</b>. Ratios of TNF-α vs. IL-10 and IL-6 vs IL-10 revealed that the combination of IFN-γ and GM-CSF produced the most inflammatory macrophage population. In donors where IFN-γ activation completely abrogated IL-10 expression, the minimum detectable limit of IL-10 for the assay (1.9 pg/ml) was used in order to calculate TNF-α/IL-10 and IL-6/IL-10 ratios. Graphs depict 5–95 percentile with median for n = 6 to 8. Significance calculated by one-way ANOVA with Tukey’s post test; * = p≤0.05, ** = p≤0.01. Unt: untreated macrophages; (-): uninfected; (+): infected.