Priming of microglia by type II interferon is lasting and resistant to modulation by interleukin-10 in situ

J Neuroimmunol. 2022 Jul 15:368:577881. doi: 10.1016/j.jneuroim.2022.577881. Epub 2022 Apr 28.

Abstract

Immunological priming by type II interferon (IFN-γ) is crucial for evoking neurotoxic phenotypes of microglia (tissue-resident macrophages). We report that serial exposure of hippocampal slice cultures to IFN-γ and lipopolysaccharide (Toll-like receptor 4 ligand) induces high release of IL-6, TNF-α and nitric oxide, concomitant loss of electrical network activity (neuronal gamma oscillations) and neurodegeneration. Notably, these effects are still present after 3 days of IFN-γ removal but neither mimicked by IFN-α nor attenuated by anti-inflammatory cytokine, IL-10. Our findings might be relevant for brain diseases featuring elevated IFN-γ levels, such as viral and bacterial infections, multiple sclerosis and Alzheimer's disease.

Keywords: Interferon-gamma; Microglia; Neuroinflammation; Priming; Slice culture; Synaptic transmission.

MeSH terms

  • Hippocampus / metabolism
  • Interferon-gamma* / metabolism
  • Interferon-gamma* / pharmacology
  • Interleukin-10
  • Lipopolysaccharides / pharmacology
  • Microglia* / metabolism
  • Neurons / metabolism
  • Nitric Oxide
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha
  • Interleukin-10
  • Nitric Oxide
  • Interferon-gamma