The innate immune response and cytokine milieu in airway mucosa, mediated by bronchial epithelial cells, are critical in determining susceptibility or protection against cryptococcosis. In experimenta Show more
The innate immune response and cytokine milieu in airway mucosa, mediated by bronchial epithelial cells, are critical in determining susceptibility or protection against cryptococcosis. In experimental models, Th2 and Th1 responses are linked to susceptibility and protection, respectively, while the roles of other cytokines remain less understood. To evaluate the in vitro effects of IL-4, IFN-γ, and IL-27 (100ng/mL) on human bronchial epithelial cells (BEAS-2B) infected with a strain of Cryptococcus neoformans sensu stricto (multiplicities of infection [MOI] 1-100). Cells were stimulated with each cytokine, followed by C. neoformans infection (MOI 100). After 24h, supernatants were collected to measure CCL2, IL-6, and IL-8 production. STAT1 and STAT6 activation was analyzed by flow cytometry. Phagocytosis and colony-forming unit assays assessed fungal internalization and growth. Cytokine-stimulated, infected cells displayed reduced IL-6 and/or CCL2 production and decreased STAT6 activation (IL-4) or STAT1 activation (IL-27, IFN-γ) compared with cells stimulated with C. neoformans sensu stricto or cytokines alone. IL-27 reduced fungal internalization, while IL-4 and IFN-γ increased it. All cytokines promoted higher fungal growth. The interaction of bronchial epithelial cells stimulated with IL-4, IFN-γ, or IL-27, with yeasts of C. neoformans induced an anti-inflammatory profile in the cells that impaired STAT activation and favored fungal proliferation. These findings suggest that certain cytokine environments within the airway epithelium may create conditions conducive to C. neoformans persistence, potentially influencing the progression of the infection. Show less
IL-4 coordinates the Th2-type immune response in inflammatory diseases such as asthma. IL-27 can inhibit the development of both Th2 and Th1 cells. However, IL-27 can also drive naïve T cells to diffe Show more
IL-4 coordinates the Th2-type immune response in inflammatory diseases such as asthma. IL-27 can inhibit the development of both Th2 and Th1 cells. However, IL-27 can also drive naïve T cells to differentiate toward the Th1 phenotype. In this study, we investigated the effects of IL-27 on the activation of IL-4-induced human bronchial epithelial cells (BEAS-2B). Compared to controls, both IL-4 and IL-27 (25-100 ng/mL) increased the concentrations of CCL2 and IL-8 in a dose-dependent manner. However, compared to cells stimulated individually with IL-4 or IL-27, treatment with a combination of both cytokines reduced CCL2 and IL-8 concentrations in a dose- and time-dependent manner. IL-4 increased the activation of p38 MAPK, ERK1/2, STAT6 and NF-κB, while IL-27 increased the activation of p38 MAPK and ERK1/2 but not STAT6 and NF-κB. Compared to IL-4-stimulated cells, cells treated with both IL-27 and IL-4 displayed decreased activation of STAT6 and NF-κB but not ERK1/2 and p38 MAPK. Taken together, these results suggest that IL-27 plays a pro-inflammatory role when administered alone but downregulates bronchial epithelial cell activation when combined with IL-4. Therefore, IL-27 may be an interesting target for the treatment of Th2 inflammatory diseases. Show less