N. Kurita et al., Antifungal activity of human polymorphonuclear leucocytes against yeast cells of Paracoccidioides brasiliensis, MED MYCOL, 37(4), 1999, pp. 261-267
Human peripheral blood polymorphonuclear leucocytes (PMN) were examined in
vitro for antifungal activity against yeast cells of Paracoccidioides brasi
liensis. The yeast cell of this fungus was resistant to killing by PMN, How
ever, PMN exhibited a fungistatic effect on the fungal isolates employed in
a long-term (similar to 72 h) assay. Lysates of PMN did not show a fungist
atic or fungicidal effect, indicating that live PMN are necessary for the a
ntifungal effect. Interferon-gamma (IFN-gamma) enhanced the antifungal acti
vity of PMN, IFN-gamma-treated PMN killed isolate Bt-4 within 2 h of cocult
ure, and after 24 h a still greater killing effect was observed. By contras
t, IFN-gamma-treated PMN did not show a significant killing effect on isola
te Tatu, but did exhibit an enhanced fungistatic effect on this isolate. In
contrast, tumor necrosis factor-alpha and interleukin 8 had no effect on t
he antifungal activity of PMN. Scanning electron microscopy revealed that t
he surface structure of the fungal cell was apparently damaged by PMN withi
n 24 h of cocultures. Based on these novel findings, we speculate that huma
n PMN might play a role in host resistance in early infection with this fun
gus due to their antifungal activity.