Natural Killer cells exhibit direct activity against hyphae, but not against conidia of Aspergillus fumigatus

Background: Natural Killer (NK) cells play an important role in the elimination of malignant and virus-infected cells. Unfortunately, little is known about the antifungal activity of human NK cells against Aspergillus fumigatus. Methods: Human NK cells from healthy donors were purified using magnetic cell sorting (Miltenyi Biotech, Germany). Analyses were performed using either unstimulated or IL2 (1000 U/ml, 7–10d) stimulated human NK cells. Antifungal activity against Aspergillus hyphae was assessed by the XTT assay and activity against conidia by determination of colony forming units (CFUs). Perforin and inte…