Contrarily, under cyclophosphamide treatment the bioluminescence signal was hardly detectable one day after infection, but steadily increased at later time points (Figure 2, inlet). As assumed,

the amount of fungal DNA detected one day after infection in cortisone acetate treated animals was generally higher than that of cyclophosphamide treated animals at the same time point, confirming an increased early germination rate of conidia under corticosteroid treatment. Surprisingly, the quantity of fungal DNA stayed rather Protein Tyrosine Kinase constant under the corticosteroid regimen. This implies that the immune response PF-6463922 in vitro under this treatment either prohibits further growth of hyphae or even kills fungal cells, which could explain the decrease in the bioluminescence signal. However, lungs explanted from mice sacrificed at day three still showed significant luminescence (Figure 1D and 2). Therefore, we assume that, besides reducing the expansion of fungal mycelium through the lung tissue, neutrophils cause extensive tissue destruction leading to tissue

hypoxia, which could attenuate the bioluminescence signal. Oxygen is an essential substrate for firefly luciferase activity BIBW2992 research buy and an oxygen saturation below 5% significantly decreases light emission [19]. Figure 2 Quantitative real-time PCR of fungal DNA enables the correlation between fungal burden and bioluminescence signals. Mice were immunosuppressed either with cortisone acetate or cyclophosphamide. Two mice from each group were sacrificed at day one and the other two animals from each group at day three after infection. An uninfected mouse was used as a negative control and revealed no signal in the qRT-PCR and is, therefore, omitted from the graph. The bars represent the amount of fungal DNA per microgram of total DNA isolated from the infected tissues with standard deviations from six data points for each individual animal. The two animals investigated for each time point and immunosuppression regimen

show the general tendency that at day one after infection the cortisone acetate treated animals show a higher burden than the cyclophosphamide treated animals. Three days after infection, the burden with alive fungal cells seems to stay rather constant under the coticosteroid treatment, Aprepitant but strongly increases under the regimen with cyclophosphamide. The inlet shows the time response of bioluminescence from alive animals with high values for the cortisone acetate treated mice early after infection followed by a decline of the signal intensity at later time points. Under cyclophosphamide regimen the bioluminescence steadily increases. The small photographs above the bars from mice sacrificed at day three show the explanted lungs with an overlay of the emitted light intensities. Numbers above the photographs give the photons/s × cm2.