Abstract
In our previous study, it was observed that human peripheral blood polymorphonuclear leucocytes (PMNs) exhibited a fungistatic effect on yeast cells of Paracoccid ioides brasiliensis, and that interferon-γ (IFN-γ), but not tumor necrosis factor-α or interleukin-8 (IL-8), enhanced the antifungal activity of PMNs. In the present study, granulocyte-macrophage colony-stimulating factor (GM-CSF) also enhanced the PMN activity. GM-CSF-activated PMNs exhibited a killing effect on P. brasiliensis isolate Bt-4 and an enhanced fungistatic effect on isolate Aoki. IL-1β activated PMNs to kill isolate Bt-4. Granulocyte colony-stimulating factor had no effect. Combinations of IFN-γ with GM-CSF or IL-1β, but not a combination of GM-CSF and IL-1β, exhibited a synergistic effect in enhancing the antifungal activity of PMNs. These results strongly suggest that PMNs activated with IFN-γ, GM-CSF and/or IL-1β might play an important role in host defense in early infection with P. brasiliensis due to their enhanced antifungal activity.
