Interleukin-17 limits hypoxia-inducible factor 1α and development of hypoxic granulomas during tuberculosis
Racquel Domingo-Gonzalez, Shibali Das, Kristin L. Griffiths, Mushtaq Ahmed, Monika Bambouskova, Radha Gopal, Suhas Gondi, Marcela Muñoz-Torrico, Miguel A. Salazar-Lezama, Alfredo Cruz-Lagunas, Luis Jiménez-Álvarez, Gustavo Ramirez-Martinez, Ramón Espinosa-Soto, Tamanna Sultana, James Lyons-Weiler, Todd A. Reinhart, Jesus Arcos, Maria de la Luz Garcia-Hernandez, Michael A. Mastrangelo, Noor Al-Hammadi, Reid Townsend, Joan-Miquel Balada-Llasat, Jordi B. Torrelles, Gilla Kaplan, William Horne, Jay K. Kolls, Maxim N. Artyomov, Javier Rangel-Moreno, Joaquín Zúñiga, Shabaana A. Khader
Racquel Domingo-Gonzalez, Shibali Das, Kristin L. Griffiths, Mushtaq Ahmed, Monika Bambouskova, Radha Gopal, Suhas Gondi, Marcela Muñoz-Torrico, Miguel A. Salazar-Lezama, Alfredo Cruz-Lagunas, Luis Jiménez-Álvarez, Gustavo Ramirez-Martinez, Ramón Espinosa-Soto, Tamanna Sultana, James Lyons-Weiler, Todd A. Reinhart, Jesus Arcos, Maria de la Luz Garcia-Hernandez, Michael A. Mastrangelo, Noor Al-Hammadi, Reid Townsend, Joan-Miquel Balada-Llasat, Jordi B. Torrelles, Gilla Kaplan, William Horne, Jay K. Kolls, Maxim N. Artyomov, Javier Rangel-Moreno, Joaquín Zúñiga, Shabaana A. Khader
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Research Article Infectious disease Inflammation

Interleukin-17 limits hypoxia-inducible factor 1α and development of hypoxic granulomas during tuberculosis

Abstract

Mycobacterium tuberculosis (Mtb) is a global health threat, compounded by the emergence of drug-resistant strains. A hallmark of pulmonary tuberculosis (TB) is the formation of hypoxic necrotic granulomas, which upon disintegration, release infectious Mtb. Furthermore, hypoxic necrotic granulomas are associated with increased disease severity and provide a niche for drug-resistant Mtb. However, the host immune responses that promote the development of hypoxic TB granulomas are not well described. Using a necrotic Mtb mouse model, we show that loss of Mtb virulence factors, such as phenolic glycolipids, decreases the production of the proinflammatory cytokine IL-17 (also referred to as IL-17A). IL-17 production negatively regulates the development of hypoxic TB granulomas by limiting the expression of the transcription factor hypoxia-inducible factor 1α (HIF1α). In human TB patients, HIF1α mRNA expression is increased. Through genotyping and association analyses in human samples, we identified a link between the single nucleotide polymorphism rs2275913 in the IL-17 promoter (–197G/G), which is associated with decreased IL-17 production upon stimulation with Mtb cell wall. Together, our data highlight a potentially novel role for IL-17 in limiting the development of hypoxic necrotic granulomas and reducing disease severity in TB.

Authors

Racquel Domingo-Gonzalez, Shibali Das, Kristin L. Griffiths, Mushtaq Ahmed, Monika Bambouskova, Radha Gopal, Suhas Gondi, Marcela Muñoz-Torrico, Miguel A. Salazar-Lezama, Alfredo Cruz-Lagunas, Luis Jiménez-Álvarez, Gustavo Ramirez-Martinez, Ramón Espinosa-Soto, Tamanna Sultana, James Lyons-Weiler, Todd A. Reinhart, Jesus Arcos, Maria de la Luz Garcia-Hernandez, Michael A. Mastrangelo, Noor Al-Hammadi, Reid Townsend, Joan-Miquel Balada-Llasat, Jordi B. Torrelles, Gilla Kaplan, William Horne, Jay K. Kolls, Maxim N. Artyomov, Javier Rangel-Moreno, Joaquín Zúñiga, Shabaana A. Khader

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Figure 1

IL-17 limits HIF1α and the metabolic shift to glycolysis, protecting against in vivo susceptibility to Mtb and development of hypoxic tuberculosis granulomas.

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IL-17 limits HIF1α and the metabolic shift to glycolysis, protecting aga...
(A and B) FeJ bone marrow–derived macrophages (BMDMs) were infected with Mycobacterium tuberculosis (Mtb) clinical strain HN878 (MOI 1) and treated with rIL-17 (100 ng/ml) for 48 hours (n = 7 biological replicates) or left uninfected (n = 4 biological replicates) and treated with rIL-17 (n = 4 biological replicates), or untreated (n = 5 biological replicates), and (A) lactate accumulation was measured by lactate assay. (B) HIF1α expression was analyzed by Western blots (representative blot on left), which were quantified by densitometry (right, n = 3 biological replicates/group). Dashed line represents uninfected control. (C–K) FeJ mice were aerosol infected with approximately 100 CFU HN878 and received IL-17–blocking antibody (100 μg) between 10 and 30 (days postinfection [d.p.i.]), and lungs were harvested at 37 d.p.i. (C) Lung bacterial burden was assessed by plating from HN878-infected isotype (n = 5 mice) and anti–IL-17–treated mice (n = 5 mice). (D) Lung area per lobe covered by inflammation on H&E–stained formalin-fixed paraffin-embedded (FFPE) sections from HN878-infected isotype-antibody-treated (n = 4 mice) and anti–IL-17–treated mice (n = 3 mice) was quantified using the morphometric tool of the Zeiss Axioplan microscope. (E) Representative H&E images shown (×50 magnification). (F) Fibrosis was assessed using Masson’s trichrome staining (×50 magnification, arrowheads depict collagen deposition). (G) Immunofluorescence staining using antibodies specific for HIF1α (red) and F4/80 (green) was carried out on FFPE sections (arrows indicate HIF1α-expressing macrophages) and (H) HIF1α staining was quantified (isotype-treated, n = 5 mice; anti–IL-17–treated, n = 10 mice). (I) Hypoxia was determined using pimonidazole (PIMO, red) and F4/80 (green) staining by immunofluorescence, ×200 magnification (arrowheads depict areas of hypoxia) and (J) PIMO staining was quantified (isotype-treated, n = 5 mice; anti–IL-17–treated, n = 10 mice). All data shown as mean ± SD. **P < 0.01, ***P < 0.001 by 1-way ANOVA (A) or Student’s t test (B–D, H, and J). ns, not significant.