The integrated stress response mediates necrosis in murine Mycobacterium tuberculosis granulomas
Bidisha Bhattacharya, … , William Bishai, Igor Kramnik
Bidisha Bhattacharya, … , William Bishai, Igor Kramnik
Published December 10, 2020
Citation Information: J Clin Invest. 2021;131(3):e130319. https://doi.org/10.1172/JCI130319.
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Research Article Immunology Infectious disease

The integrated stress response mediates necrosis in murine Mycobacterium tuberculosis granulomas

Abstract

The mechanism by which only some individuals infected with Mycobacterium tuberculosis develop necrotic granulomas with progressive disease while others form controlled granulomas that contain the infection remains poorly defined. Mice carrying the sst1-suscepible (sst1S) genotype develop necrotic inflammatory lung lesions, similar to human tuberculosis (TB) granulomas, which are linked to macrophage dysfunction, while their congenic counterpart (B6) mice do not. In this study we report that (a) sst1S macrophages developed aberrant, biphasic responses to TNF characterized by superinduction of stress and type I interferon pathways after prolonged TNF stimulation; (b) the late-stage TNF response was driven via a JNK/IFN-β/protein kinase R (PKR) circuit; and (c) induced the integrated stress response (ISR) via PKR-mediated eIF2α phosphorylation and the subsequent hyperinduction of ATF3 and ISR-target genes Chac1, Trib3, and Ddit4. The administration of ISRIB, a small-molecule inhibitor of the ISR, blocked the development of necrosis in lung granulomas of M. tuberculosis–infected sst1S mice and concomitantly reduced the bacterial burden. Hence, induction of the ISR and the locked-in state of escalating stress driven by the type I IFN pathway in sst1S macrophages play a causal role in the development of necrosis in TB granulomas. Interruption of the aberrant stress response with inhibitors such as ISRIB may offer novel host-directed therapy strategies.

Authors

Bidisha Bhattacharya, Shiqi Xiao, Sujoy Chatterjee, Michael Urbanowski, Alvaro Ordonez, Elizabeth A. Ihms, Garima Agrahari, Shichun Lun, Robert Berland, Alexander Pichugin, Yuanwei Gao, John Connor, Alexander R. Ivanov, Bo-Shiun Yan, Lester Kobzik, Bang-Bon Koo, Sanjay Jain, William Bishai, Igor Kramnik

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Figure 3

Effect of ISR inhibitor ISRIB on tuberculosis progression in B6.Sst1S mice.

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Effect of ISR inhibitor ISRIB on tuberculosis progression in B6.Sst1S mi...
For all figure panels, IS = ISRIB. (A) Lung bacillary loads at weeks 4 and 8 after treatment start. Data plotted as means ± SEM. Asterisks indicate significant differences between treatment groups compared with vehicle control group calculated by 2-way ANOVA. *Indicates significance at 90% CI. **Indicates significance at 95% CI. (B) Representative H&E-stained lung tissue slices from mice in the vehicle control group and the ISRIB-treated group with 0.25 mg/kg by body weight. Scale bars: 3 mm. (C) Extent of inflammation and necrosis in lungs of mice treated with vehicle (control) or ISRIB. Each data point represents a survey of 1 mouse. All P values were calculated based on a nonparametric Kruskal-Wallis test comparing the control to each of the dosing groups while accounting for multiple comparisons. NS, P > 0.20. Fractions above group columns indicate the numbers of mice where necrosis was identified divided by the number of mice in the analysis group. (D) Fraction of lung volume with disease density as a quantitative measure of severity of disease in mouse lungs at week 8. Data summary elements represent mean fraction of voxels ± SEM. P values calculated based on Welch’s t test. NS, not significant. Numbers above group columns indicate number of mice surveyed. (E) [18F]FMISO PET/CT imaging of mouse lungs at week 8. Quantification is given as dose- and decay-corrected standardized uptake value (SUV) of lesions normalized to the PET signal from PET-blinded CT-scan selection of nondisease lung space volumes. P values calculated by nonparametric 2-tailed Mann-Whitney test. For graphs in C and E, data summary elements indicate means ± SD.