Toll-like receptor 7 preconditioning induces robust neuroprotection against stroke by a novel type i interferon-mediated mechanism

Philberta Y. Leung, Susan L. Stevens, Amy E B Packard, Nikola S. Lessov, Tao Yang, Valerie K. Conrad, Noortje N A M Van Den Dungen, Roger P. Simon, Mary Stenzel-Poore

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Background and Purpose-Systemic administration of Toll-like receptor (TLR) 4 and TLR9 agonists before cerebral ischemia have been shown to reduce ischemic injury by reprogramming the response of the brain to stroke. Our goal was to explore the mechanism of TLR-induced neuroprotection by determining whether a TLR7 agonist also protects against stroke injury. Methods-C57Bl/6, TNF -/-, interferon (IFN) regulatory factor 7 -/-, or type I IFN receptor (IFNAR) -/- mice were subcutaneously administered the TLR7 agonist Gardiquimod (GDQ) 72 hours before middle cerebral artery occlusion. Infarct volume and functional outcome were determined after reperfusion. Plasma cytokine responses and induction of mRNA for IFN-related genes in the brain were measured. IFNAR -/- mice also were treated with the TLR4 agonist (lipopolysaccharide) or the TLR9 agonist before middle cerebral artery occlusion and infarct volumes measured. Results-The results show that GDQ reduces infarct volume as well as functional deficits in mice. GDQ pretreatment provided robust neuroprotection in TNF -/- mice, indicating that TNF was not essential. GDQ induced a significant increase in plasma IFNα levels and both IRF7 -/- and IFNAR -/- mice failed to be protected, implicating a role for IFN signaling in TLR7-mediated protection. Conclusions-Our studies provide the first evidence that TLR7 preconditioning can mediate neuroprotection against ischemic injury. Moreover, we show that the mechanism of protection is unique from other TLR preconditioning ligands in that it is independent of TNF and dependent on IFNAR.

Original languageEnglish (US)
Pages (from-to)1383-1389
Number of pages7
JournalStroke
Volume43
Issue number5
DOIs
StatePublished - May 2012

Fingerprint

Toll-Like Receptor 7
Interferons
Stroke
Toll-Like Receptors
Middle Cerebral Artery Infarction
Interferon Regulatory Factor-7
Wounds and Injuries
Interferon alpha-beta Receptor
Toll-Like Receptor 4
Brain
Brain Ischemia
Reperfusion
Lipopolysaccharides
Neuroprotection
Cytokines
Ligands
Messenger RNA
gardiquimod
Genes

Keywords

  • Ischemia
  • Neuroprotection

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Clinical Neurology
  • Advanced and Specialized Nursing

Cite this

Toll-like receptor 7 preconditioning induces robust neuroprotection against stroke by a novel type i interferon-mediated mechanism. / Leung, Philberta Y.; Stevens, Susan L.; Packard, Amy E B; Lessov, Nikola S.; Yang, Tao; Conrad, Valerie K.; Van Den Dungen, Noortje N A M; Simon, Roger P.; Stenzel-Poore, Mary.

In: Stroke, Vol. 43, No. 5, 05.2012, p. 1383-1389.

Research output: Contribution to journalArticle

Leung, PY, Stevens, SL, Packard, AEB, Lessov, NS, Yang, T, Conrad, VK, Van Den Dungen, NNAM, Simon, RP & Stenzel-Poore, M 2012, 'Toll-like receptor 7 preconditioning induces robust neuroprotection against stroke by a novel type i interferon-mediated mechanism', Stroke, vol. 43, no. 5, pp. 1383-1389. https://doi.org/10.1161/STROKEAHA.111.641522
Leung, Philberta Y. ; Stevens, Susan L. ; Packard, Amy E B ; Lessov, Nikola S. ; Yang, Tao ; Conrad, Valerie K. ; Van Den Dungen, Noortje N A M ; Simon, Roger P. ; Stenzel-Poore, Mary. / Toll-like receptor 7 preconditioning induces robust neuroprotection against stroke by a novel type i interferon-mediated mechanism. In: Stroke. 2012 ; Vol. 43, No. 5. pp. 1383-1389.
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