• Media type: E-Article
  • Title: TLR4-activated microglia require IFN-γ to induce severe neuronal dysfunction and death in situ
  • Contributor: Papageorgiou, Ismini E.; Lewen, Andrea; Galow, Lukas V.; Cesetti, Tiziana; Scheffel, Jörg; Regen, Tommy; Hanisch, Uwe-Karsten; Kann, Oliver
  • imprint: Proceedings of the National Academy of Sciences, 2016
  • Published in: Proceedings of the National Academy of Sciences
  • Language: English
  • DOI: 10.1073/pnas.1513853113
  • ISSN: 1091-6490; 0027-8424
  • Origination:
  • Footnote:
  • Description: <jats:title>Significance</jats:title> <jats:p>Microglia (brain macrophages) become rapidly activated in most neuropsychiatric disorders. A popular concept is that a single pathogenic stimulus, such as bacterial lipopolysaccharide (LPS) through Toll-like receptor 4 (TLR4), is sufficient to induce a reactive proinflammatory phenotype in microglia that exerts neurotoxicity. This concept is biologically risky, however. Here we provide evidence that chronic activation with either LPS or the leukocyte cytokine IFN-γ induces different reactive phenotypes in microglia of postnatal hippocampal tissue. Notably, these phenotypes only moderately alter diverse neuronal functions. In contrast, coactivation of TLR4 and IFN-γ receptors results in massive neural dysfunction and death. Thus, activation of TLR4 in microglia in situ requires concomitant IFN-γ signaling from other host immune cells to induce neurodegeneration.</jats:p>
  • Access State: Open Access