Fig 5. 15-keto-PGE2 promotes fungal burden by activating host PPAR- γ.
A i J774 macrophages treated with Troglitazone (TLT—0.25 μM), an equivalent DMSO control or infected with H99 or Δplb1 fixed and stained at 18 hpi with Hoechst and antibody against PPAR-γ. Nuclear localization of PPAR-γ quantified by measuring nuclear grey value of at least 30 cells per condition. A single experiment is shown that is representative of n = 2. One way ANOVA with Tukey post-test used to compare all conditions. DMSO vs. TLT ** p = 0.0049. DMSO vs H99 ** p = 0.0040. TLT vs Δplb1 * p = 0.0212. H99 vs. Δplb1 * p = 0.0187. A ii Transgenic zebrafish larvae with a GFP PPAR- γ reporter treated with DMSO, 250 nM Troglitazone or 10 μM 15-keto-PGE2 + 250 nM Troglitazone overnight and imaged. Lateral views of 2 dpf embryos, anterior to the left, are shown. B J774 murine macrophages infected with Δplb1 or the parental strain H99. Infected cells treated with 25 μM GW9662 (a PPAR-γ antagonist) or equivalent solvent (DMSO) control. Mean IPR from 6 biological repeats shown with error bars representing standard deviation. An unpaired two tailed Student’s t-test was performed to compare each treatment group. H99 DMSO vs. H99 25 μM GW9662 * p = 0.026. C Δplb1-GFP infected larvae treated with 10 μM 15-keto-PGE2, 500 nM GW9662, 10 μM 15-keto-PGE2 + 500 nM GW9662 or an equivalent solvent (DMSO) control. Box and whiskers show median, 5th percentile and 95th percentile. At least 35 larvae measured per treatment group from 2 biological repeats. Mann-Whitney U test used to compare between treatments. DMSO vs. 15-keto-PGE2 **** p <0.0001 (threshold for significance 0.025, corrected for multiple comparisons), 15-keto-PGE2 vs. 15-keto-PGE2 + 500 nm GW9662 ** p = 0.005 (threshold for significance 0.025, corrected for multiple comparisons) D-F 2 day old (2 dpf) Nacre zebrafish larvae injected with 500 cell inoculum. Fungal burden measured at 2 days post infection (2 dpi) by counting GFP positive pixels within each larvae. D i H99-GFP Infected larvae treated with 0.55 μM Troglitazone (TLT) equivalent solvent (DMSO) control. Box and whiskers show median, 5th percentile and 95th percentile. At least 55 larvae measured per treatment group over 3 biological repeats. Mann-Whitney U test used to compare between treatments, DMSO vs. 0.55 μM Troglitazone ** p = 0.0044 (threshold for significance 0.025, corrected for multiple comparisons). E i Δplb1-GFP infected larvae treated with 0.55 μM Troglitazone (TLT) equivalent solvent (DMSO) control. Box and whiskers show median, 5th percentile and 95th percentile. At least 35 larvae measured per treatment group from 2 biological repeats. Mann-Whitney U test used to compare between treatments, DMSO vs. 0.55 μM Troglitazone ** p = 0.0089 (threshold for significance 0.025, corrected for multiple comparisons). F i Δlac1-GFP infected larvae treated with 0.55 μM Troglitazone (TLT) equivalent solvent (DMSO) control. At least 60 larvae measured per treatment group from 3 biological repeats. Box and whiskers show median, 5th percentile and 95th percentile, DMSO vs. 0.55 μM Troglitazone * p = 0.01 (threshold for significance 0.025, corrected for multiple comparisons). D ii, E ii and F ii, Representative GFP images (representative = median value) C. neoformans infected larvae, at 2 dpi treated with 0.55 μM Troglitazone (TLT) D ii - H99-GFP, E ii - Δplb1-GFP and F ii Δlac1-GFP.