Subinhibitory Concentrations of the Antifungal Drug CF Cause Exposure of β-Glucan

<p>Wild-type C. albicans (CAF2) was grown overnight for ten generations in YPD medium, favoring yeast-form growth (A, B, C, and E) or RPMI medium, favoring hyphal growth (D). Cultures grown at one-quarter and one-eighth of the CF MIC₅₀ were stained with anti-β-glucan antibody and Cy3-labeled secondary antibody (A and D) for visualization by microscopy or with PE-labeled secondary antibody (B) for FACS quantification. Mean fluorescence intensity (MFI) values were 9, 65, and 161, respectively, for no treatment, one-eighth the CF MIC₅₀, and one-quarter the CF MIC₅₀. Concurrently, cells were labeled briefly with propidium iodide to assess viability and visualized by epifluorescence microscopy or quantified by FACS (C). Cells grown overnight in YPD with or without CF were UV-inactivated and then exposed to BMDMs at a yeast:macrophage ratio of 10:1. Supernatants were taken at 6 h and assayed for TNFα (E).