STAT3 Represses Nitric Oxide Synthesis in Human Macrophages upon Mycobacterium tuberculosis Infection

Sci Rep. 2016 Jul 7:6:29297. doi: 10.1038/srep29297.

Abstract

Mycobacterium tuberculosis is a successful intracellular pathogen. Numerous host innate immune responses signaling pathways are induced upon mycobacterium invasion, however their impact on M. tuberculosis replication is not fully understood. Here we reinvestigate the role of STAT3 specifically inside human macrophages shortly after M. tuberculosis uptake. We first show that STAT3 activation is mediated by IL-10 and occurs in M. tuberculosis infected cells as well as in bystander non-colonized cells. STAT3 activation results in the inhibition of IL-6, TNF-α, IFN-γ and MIP-1β. We further demonstrate that STAT3 represses iNOS expression and NO synthesis. Accordingly, the inhibition of STAT3 is detrimental for M. tuberculosis intracellular replication. Our study thus points out STAT3 as a key host factor for M. tuberculosis intracellular establishment in the early stages of macrophage infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Chemokine CCL4 / metabolism
  • Humans
  • Immunity, Innate / immunology
  • Interferon-gamma / metabolism
  • Interleukin-10 / metabolism
  • Interleukin-6 / metabolism
  • Macrophages / metabolism*
  • Macrophages / microbiology
  • Mice
  • Mycobacterium tuberculosis / immunology
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase / metabolism*
  • Nitric Oxide Synthase Type II / metabolism
  • RAW 264.7 Cells
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction / physiology
  • Tuberculosis / immunology
  • Tuberculosis / metabolism*
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Chemokine CCL4
  • Interleukin-6
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Tumor Necrosis Factor-alpha
  • Interleukin-10
  • Nitric Oxide
  • Interferon-gamma
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II