Figure 1

C. parapsilosis functionally activates monocyte-derived dendritic cells resulting in increased phagocytosis and killing efficiency. Panels A and B show representative images of iDCs incubated with unopsonized FITC-labeled wild type (Panel A) and lipase deficient (Panel B) yeast cells at 1 h post-infection. Note that the majority of host cells express CD83, a dendritic cell marker. Panel C shows the FACS plots of DCs infected with wild type (Cp wt) or lipase deficient (Cp lip^-/-) yeasts at 1 h post-infection. Data on Panels D and E shows the phagocytosis of DCs and are presented as the percent of ingesting cells (percent of DCs containing at least one ingested yeast cell; Panel D) and the phagocytic index (total number of ingested yeast/100 DCs; Panel E). Panel F represents the fungicidal efficiency of DCs, infected with wt or lip^-/- C. parapsilosis. Panel G shows representative images of DCs incubated with unopsonized FITC-labeled wild type (Cp wt) or lipase deficient (Cp lip^-/-) yeasts at 1 h post-infection. Lysosomes were visualized by LysoTracker Red. Asterisks show the co-localization of mature lysosomes (red) and phagocytosed yeast cells (green). Data on panel H shows the percentage of the dead-cells as determined by protease activity at 1 h post-infection as compared to the untreated control cells. The data on Panels D-E and H are represented as mean ± SEM of six and two experiments with different donors, respectively. DAPI - 4',6-diamidino-2-phenylindole; wt - wild type; lip^-/- - lipase deficient. Scale bars: panels A and B: 20 μm; panel G: 5 μm.