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. 2017 Aug 18;85(9):e00276-17. doi: 10.1128/IAI.00276-17

FIG 1.

FIG 1

Neutrophils but not macrophages protect against death in the zebrafish mucosal candidiasis model. (A) Diagram of the swim bladder injection model used in this study. (B) Schematic of the strategy used to test the role of neutrophils and macrophages in protection against mucosal candidiasis. (C to F) At 4 days postfertilization (dpf), zebrafish of the wild-type (WT) (C and D), mpeg1-NTR (E), and mpo:Rac2-D57N (F) lines were infected with 4 nl of Caf2-dTomato (Caf2-dTom) yeast cells (3 × 107 CFU/ml in 5% polyvinylpyrrolidone [PVP]) or with PVP only. Fish were incubated in different chemical inhibitors (B) for an hour prior to injection: the CXCR2 inhibitor SB225002 at 2 μg/ml or 0.02% DMSO (C), the pan-PI3K inhibitor LY294002 at 5 μg/ml or 0.05% DMSO (D), or metronidazole (Mtx) at 20 mM (E). Fish were screened immediately after injection, and only fish with 50 to 100 yeast cells in the inoculum in the swim bladder were selected. Fish were returned to the chemical inhibitor or vehicle (C and D) at the same concentration or to Mtx (5 mM) (E), and survival was monitored daily for 3 days. Data pooled from three independent experiments are represented and were analyzed by the Kaplan-Meier test. Data are for 56, 57, 52, and 50 fish for the four groups indicated from top to bottom, respectively, in the key to panel C; 40, 43, 32, and 38 fish for the four groups indicated from top to bottom, respectively, in the key to panel D; 42, 34, and 33 fish for the three groups indicated from top to bottom, respectively, in the key to panel E; and 50, 53, 52, and 55 fish for the four groups indicated from top to bottom, respectively, in the key to panel F. Log-rank (Mantel-Cox) statistical tests showed that the results for fish infected with C. albicans and treated with an inhibitor (C.a. infection [Ifx]/inhibitor [inh]) and fish infected with C. albicans and treated with the vehicle (C.a. Ifx/Vehicle) or fish mock infected and treated with a CXCR2 inhibitor (Mock Ifx/CXCR2 inh) were significantly different (P < 0.0001) in panels C, D, and F but not in panel E. By the same test, in panel D, the results for fish mock infected and treated with the vehicle (Mock Ifx/Vehicle) were significantly different from those for fish mock infected and treated with the PI3K inhibitor (Mock Ifx/PI3K inh) (P = 0.0013). **, P < 0.01; ****, P < 0.0001.