1. Microanatomic Distribution of Myeloid Heme Oxygenase-1 Protects against Free Radical-Mediated Immunopathology in Human Tuberculosis
- Author
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Krishna C. Chinta, Md. Aejazur Rahman, Vikram Saini, Joel N. Glasgow, Vineel P. Reddy, Jeremie M. Lever, Shepherd Nhamoyebonde, Alasdair Leslie, Ryan M. Wells, Amie Traylor, Rajhmun Madansein, Gene P. Siegal, Veena B. Antony, Jessy Deshane, Gordon Wells, Kievershen Nargan, James F. George, Pratistadevi K. Ramdial, Anupam Agarwal, and Adrie J.C. Steyn
- Subjects
CD4-Positive T-Lymphocytes ,Free Radicals ,NF-E2-Related Factor 2 ,Neutrophils ,Nitric Oxide Synthase Type II ,macrophage ,Article ,General Biochemistry, Genetics and Molecular Biology ,human TB pathology ,human pulmonary tuberculosis ,Animals ,Humans ,Tuberculosis ,Myeloid Cells ,lcsh:QH301-705.5 ,Lung ,histopathological spectrum ,free radical ,Inflammation ,Mice, Knockout ,Granuloma ,Arginase ,neutrophil ,Mycobacterium tuberculosis ,Mice, Inbred C57BL ,lcsh:Biology (General) ,myeloid cell inflammation ,Cytokines ,karyorrhexis ,Heme Oxygenase-1 - Abstract
Summary Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that controls inflammatory responses and redox homeostasis; however, its role during pulmonary tuberculosis (TB) remains unclear. Using freshly resected human TB lung tissue, we examined the role of HO-1 within the cellular and pathological spectrum of TB. Flow cytometry and histopathological analysis of human TB lung tissues showed that HO-1 is expressed primarily in myeloid cells and that HO-1 levels in these cells were directly proportional to cytoprotection. HO-1 mitigates TB pathophysiology by diminishing myeloid cell-mediated oxidative damage caused by reactive oxygen and/or nitrogen intermediates, which control granulocytic karyorrhexis to generate a zonal HO-1 response. Using whole-body or myeloid-specific HO-1-deficient mice, we demonstrate that HO-1 is required to control myeloid cell infiltration and inflammation to protect against TB progression. Overall, this study reveals that zonation of HO-1 in myeloid cells modulates free-radical-mediated stress, which regulates human TB immunopathology., Graphical Abstract, Highlights • HO-1 is expressed in distinct microanatomic zones within the human TB lung • Macrophages and neutrophils are the major producers of HO-1 in human TB lungs • In diseased areas of human TB lungs, myeloid cells have low HO-1 and high ROS and RNS • Mice lacking HO-1 expression in myeloid cells are more susceptible to Mtb infection, Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that controls inflammation and redox homeostasis; however, its role in tuberculosis (TB) is unclear. Using freshly resected human lung tissue and HO-1-deficient mice, Chinta et al. demonstrate that HO-1 in myeloid cells is important for controlling inflammatory and free-radical-mediated tissue damage in TB.
- Published
- 2019
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