FIGURE 4.

Activation of SFKs in A549 cells during interaction with H. capsulatum, and effect of PP2 on IL-6 and IL-8 secretion by A549 cells during interaction with H. capsulatum. (A) A549 cells were incubated with H. capsulatum yeasts for 15, 30, 60, 120 or 180 min, and then P-SFK (Tyr⁴¹⁶) was analyzed by Western blot. SFK was used as protein loading control. Relative SFK phosphorylation was determined by densitometric analysis of bands obtained by Western blot, and values represent the ratio of the intensity of P-SFK band divided by the corresponding intensity of SFK band. Blots are representative of three independent experiments. (B) A549 cells were incubated for 2 h in the absence or presence of 0.1, 1, or 10 μM PP2 (an inhibitor of SFK activation), and then, with H. capsulatum yeasts (Hc) for 16 h. After incubation with fungi, culture supernatants were collected, and IL-6 and IL-8 levels were determined by ELISA. To analyze basal cytokine levels, A549 cells were incubated in the absence of PP2 and H. capsulatum (PP2 0/Hc -). Values represent the mean of triplicate experiments ± the standard deviation. ^∗p < 0.01 when compared to A549 cells incubated in the absence of PP2 and H. capsulatum (PP2 0/Hc -). #p < 0.01 when compared to A549 cells incubated with H. capsulatum in the absence of PP2 (PP2 0/Hc +). Similar results were obtained from three independent experiments.