Open AccessSpatial Network Mapping of Pulmonary Multidrug-Resistant Tuberculosis Cavities Using RNA Sequencing
Author(s) -
Keertan Dheda,
Laura Lenders,
Shashikant Srivastava,
Gesham Magombedze,
Helen Wainwright,
Prithvi Raj,
Stephen J. Bush,
Gabriele Pollara,
Rachelle Steyn,
Malika Davids,
Anil Pooran,
Timothy Pennel,
Anthony Linegar,
Ruth McNerney,
Loven Moodley,
Jotam G. Pasipanodya,
Chris Turner,
Mahdad Noursadeghi,
Robin M. Warren,
Edward K. Wakeland,
Tawanda Gumbo
Publication year - 2019
Publication title -
american journal of respiratory and critical care medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.272
H-Index - 374
eISSN - 1535-4970
pISSN - 1073-449X
DOI - 10.1164/rccm.201807-1361oc
Subject(s) - medicine , in silico , proinflammatory cytokine , tuberculosis , immunology , signal transduction , lung , biology , inflammation , microbiology and biotechnology , pathology , gene , genetics
Rationale: There is poor understanding about protective immunity and the pathogenesis of cavitation in patients with tuberculosis. Objectives: To map pathophysiological pathways at anatomically distinct positions within the human tuberculosis cavity. Methods: Biopsies were obtained from eight predetermined locations within lung cavities of patients with multidrug-resistant tuberculosis undergoing therapeutic surgical resection ( n = 14) and healthy lung tissue from control subjects without tuberculosis ( n = 10). RNA sequencing, immunohistochemistry, and bacterial load determination were performed at each cavity position. Differentially expressed genes were normalized to control subjects without tuberculosis, and ontologically mapped to identify a spatially compartmentalized pathophysiological map of the cavity. In silico perturbation using a novel distance-dependent dynamical sink model was used to investigate interactions between immune networks and bacterial burden, and to integrate these identified pathways. Measurements and Main Results: The median (range) lung cavity volume on positron emission tomography/computed tomography scans was 50 cm 3 (15-389 cm 3 ). RNA sequence reads (31% splice variants) mapped to 19,049 annotated human genes. Multiple proinflammatory pathways were upregulated in the cavity wall, whereas a downregulation "sink" in the central caseum-fluid interface characterized 53% of pathways including neuroendocrine signaling, calcium signaling, triggering receptor expressed on myeloid cells-1, reactive oxygen and nitrogen species production, retinoic acid-mediated apoptosis, and RIG-I-like receptor signaling. The mathematical model demonstrated that neuroendocrine, protein kinase C-θ, and triggering receptor expressed on myeloid cells-1 pathways, and macrophage and neutrophil numbers, had the highest correlation with bacterial burden ( r > 0.6), whereas T-helper effector systems did not. Conclusions: These data provide novel insights into host immunity to Mycobacterium tuberculosis -related cavitation. The pathways defined may serve as useful targets for the design of host-directed therapies, and transmission prevention interventions.