parapsilosis strains induced the expression of chemotactic molecules, in FG-4592 addition, DCs infected with lipase deficient yeast showed increased cell death which is known to be accompanied by the release of danger signals [25]. Consequently, we propose that DCs infected with lipase deficient yeast cells activate more robust immune response. Although both wild type

and lipase deficient C. parapsilosis induced strong, time-dependent activation of pro-inflammatory genes such as IL-1α, IL-6, TNF-α, and CXCL-8 in both DC types, lipase deficient yeast induced significantly higher gene expression of EPZ004777 datasheet effector molecules. Since locally produced chemotactic factors are presumed to mediate the sequence of events leading to the infiltration of immune cells at inflammatory sites, local expression of pro-inflammatory mediators after contact with C. parapsilosis could have an initiator role in the attraction of additional immune cells to the sites of infection. This is supported by the fact that CXCL8 is one of the most potent neutrophil chemoattractants [26] that affects not only the recruitment CRT0066101 of neutrophils into the tissues but also modulates the ability of these neutrophils to cross epithelial barriers and to kill pathogens. In addition, TNF-α

enhances the fungicidal properties of neutrophils, promotes the adhesion of immune to endothelial cells and acts as a danger signal. Corresponding to this finding, we found that DCs infected with lipase deficient yeast cells displayed increased protease activity, which accompanies cell death and the release of danger signals. Finally, TNF-α, IL-1α and IL-6 are also implicated in the induction of antimicrobial peptide expression in epithelial cells [27]. Taken together,

the secretion of pro-inflammatory mediators and the release of danger signals by DCs as a response to C. parapsilosis may play a crucial role in the recruitment of immune cells into the sites of infection. Conclusions Our work shows that C. parapsilosis activates monocyte-derived DCs, as demonstrated by increased phagocytosis and killing of yeast cells and proinflammatory protein secretion. Moreover, we found that DCs infected with lipase deficient C. parapsilosis are functionally more potent relative Molecular motor to DCs infected with wild type yeast cells, which suggests that lipase interferes with DC activation. This finding was unexpected because lipases of other pathogenic microorganisms are considered to be inducers of immune response, consequently one would have predicted a decreased activation phenotype in response to lipase deficient C. parapsilosis. The fact that this was not the case appears to result, at least in part, the DC activation is suppressed by the C. parapsilosis lipase. Further studies will be required to identify the defective anti-C. parapsilosis effector mechanisms that increase susceptibility to invasive candidiasis and to determine how C.