An evolutionary recent IFN/IL-6/CEBP axis is linked to monocyte expansion and tuberculosis severity in humans

Elife. 2019 Oct 22;8:e47013. doi: 10.7554/eLife.47013.


Monocyte counts are increased during human tuberculosis (TB) but it has not been determined whether Mycobacterium tuberculosis (Mtb) directly regulates myeloid commitment. We demonstrated that exposure to Mtb directs primary human CD34+ cells to differentiate into monocytes/macrophages. In vitro myeloid conversion did not require type I or type II IFN signaling. In contrast, Mtb enhanced IL-6 responses by CD34+ cell cultures and IL-6R neutralization inhibited myeloid differentiation and decreased mycobacterial growth in vitro. Integrated systems biology analysis of transcriptomic, proteomic and genomic data of large data sets of healthy controls and TB patients established the existence of a myeloid IL-6/IL6R/CEBP gene module associated with disease severity. Furthermore, genetic and functional analysis revealed the IL6/IL6R/CEBP gene module has undergone recent evolutionary selection, including Neanderthal introgression and human pathogen adaptation, connected to systemic monocyte counts. These results suggest Mtb co-opts an evolutionary recent IFN-IL6-CEBP feed-forward loop, increasing myeloid differentiation linked to severe TB in humans.

Keywords: Mycobacterium; computational biology; evolution; human; immunology; inflammation; interferons; interleukins; systems biology; tuberculosis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD34
  • CCAAT-Enhancer-Binding Proteins / genetics
  • CCAAT-Enhancer-Binding Proteins / metabolism*
  • Cell Differentiation
  • Cell Proliferation
  • Cytokines / genetics
  • Cytokines / metabolism
  • Genome-Wide Association Study
  • Humans
  • Hydrolases
  • Interferons / genetics
  • Interferons / metabolism*
  • Interleukin-6 / genetics
  • Interleukin-6 / metabolism*
  • Macrophages / microbiology
  • Monocytes / metabolism*
  • Monocytes / microbiology
  • Mycobacterium tuberculosis / immunology*
  • Mycobacterium tuberculosis / pathogenicity
  • Myeloid Cells / physiology
  • Proteomics
  • Receptors, Interleukin-6
  • Severity of Illness Index
  • Transcriptome
  • Tuberculosis / immunology*
  • Tuberculosis / metabolism


  • Antigens, CD34
  • CCAAT-Enhancer-Binding Proteins
  • Cytokines
  • Interleukin-6
  • Receptors, Interleukin-6
  • Interferons
  • Hydrolases
  • HsaD protein, Mycobacterium tuberculosis

Associated data

  • GEO/GSE63548
  • GEO/GSE19443
  • GEO/GSE19435
  • GEO/GSE19439
  • GEO/GSE19444