A metabolic inhibitor arms macrophages to kill intracellular fungal pathogens by manipulating zinc homeostasis
Diego C.P. Rossi, … , Jan Rupp, George S. Deepe Jr.
Diego C.P. Rossi, … , Jan Rupp, George S. Deepe Jr.
Published July 8, 2021
Citation Information: J Clin Invest. 2021;131(16):e147268. https://doi.org/10.1172/JCI147268.
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Research Article Infectious disease Microbiology Article has an altmetric score of 11

A metabolic inhibitor arms macrophages to kill intracellular fungal pathogens by manipulating zinc homeostasis

Abstract

Macrophages deploy numerous strategies to combat invasion by microbes. One tactic is to restrict acquisition of diverse nutrients, including trace metals, a process termed nutritional immunity. Intracellular pathogens adapt to a resource-poor environment by marshaling mechanisms to harvest nutrients. Carbon acquisition is crucial for pathogen survival; compounds that reduce availability are a potential strategy to control intracellular replication. Treatment of macrophages with the glucose analog 2-deoxy-D-glucose (2-DG) armed phagocytes to eliminate the intracellular fungal pathogen Histoplasma capsulatum in vitro and in vivo. Killing did not rely on altering access to carbon-containing molecules or changes in ATP, ER stress, or autophagy. Unexpectedly, 2-DG undermined import of exogenous zinc into macrophages, decreasing the quantity of cytosolic and phagosomal zinc. The fungus perished as a result of zinc starvation. This change in metal ingress was not ascribed to a defect in a single importer; rather, there was a collective impairment in transporter activity. This effect promoted the antifungal machinery of macrophages and expanded the complexity of 2-DG activities far beyond manipulating glycolysis. Mechanistic metabolic studies employing 2-DG will have to consider its effect on zinc transport. Our preclinical data support consideration of this agent as a possible adjunctive therapy for histoplasmosis.

Authors

Diego C.P. Rossi, Julio A. Landero Figueroa, William R. Buesing, Kathleen Candor, Logan T. Blancett, Heather M. Evans, Rena Lenchitz, Bradford L. Crowther III, Waleed Elsegeiny, Peter R. Williamson, Jan Rupp, George S. Deepe Jr.

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Figure 1

Macrophages fortified by 2-DG kill intracellular H.

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Macrophages fortified by 2-DG kill intracellular H. capsulatum. (A) CFU...
capsulatum. (A) CFU and XTT assay from BMDMs infected and treated with 2-DG. One-way ANOVA with Tukey’s multiple-comparison test. (B) XTT assay from infected human macrophages, MOI 1:5, treated with 5 mM 2-DG. Assay was done after 24 hours of infection. Two-tailed t test. (C) CFU assay from infected BMDMs, MOI 1:5, treated with 5 mM 2-DG. Line represents the initial inoculum, 1 × 106. Two-way ANOVA with Sidak’s multiple-comparison test. (D) XTT assay from BMDMs infected (MOI 1:5) and treated with 2-DG (5 mM), 2-FDM (5 mM), and 2-FDG (5 mM) for 24 hours. One-way ANOVA with Tukey’s multiple-comparison test. (E) XTT kinetics of H. capsulatum viability from BMDMs treated with 5 mM 2-DG. (F) CFU assay from infected BMDMs treated with 5 mM 2-DG. Two-tailed t test. (G) XTT assay from yeasts treated with 5 mM 2-DG for 24 hours. Two-tailed t test. (H) Before infection, yeasts were preincubated with 5 mM 2-DG for 6 hours. After several washes, BMDMs were infected, MOI 1:5. After 24 hours, XTT assays were performed. Two-tailed t test. (I) XTT assay from BMDMs treated with 5 mM 2-DG. Two-tailed t test. (J) Phagocytosis assay from infected BMDMs treated with 5 mM 2-DG. Two-tailed t test. Data are representative of 10 (A), 6 (A: XTT, and J), 5 (B, E, G, and I), 7 (C), 4 (D and F), or 8 (H) independent experiments. Violin plots show the median (line) and quartiles (dashed line). ***P < 0.001; ****P < 0.0001.