T cell infiltration after chronic constriction injury of mouse sciatic nerve is associated with interleukin-17 expression

Exp Neurol. 2006 Aug;200(2):480-5. doi: 10.1016/j.expneurol.2006.03.014. Epub 2006 May 3.


Interleukin (IL)-17A, a recently described novel T cell cytokine, orchestrates inflammation in a variety of immune-mediated diseases. In the present investigation, we analyzed the temporal gene expression pattern of IL-17A and its main regulators IL-23 and IL-15 after chronic constriction injury (CCI) of the sciatic nerve, a lesion paradigm inducing neuropathic pain, by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in mice. IL-17A displayed a monophasic expression in degenerating nerves at day 7 after CCI while transcripts for the IL-17A regulatory cytokines IL-23 and IL-15 peaked earlier. Accordingly, IL-17A positive T cells were detectable within the endoneurium of the injured nerves by immunocytochemistry. In support of a crucial role of T cell inflammation, RAG-1 knockout mice lacking functional T lymphocytes did not express IL-17A mRNA in distal nerve segments following CCI. Interestingly, T cell deficiency was associated with less thermal hyperalgesia and reduced mRNA levels for the macrophage marker molecule F4/80 and the chemokine macrophage chemoattractant protein-1 (MCP-1) after CCI. Our study supports the notion that T cells and T-cell-derived cytokines contribute to the inflammatory response after peripheral nerve injury.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Behavior, Animal
  • CD3 Complex / metabolism
  • Constriction
  • Gene Expression Regulation / physiology*
  • Homeodomain Proteins / genetics
  • Immunohistochemistry / methods
  • Interleukin-15 / genetics
  • Interleukin-15 / metabolism
  • Interleukin-17 / genetics
  • Interleukin-17 / metabolism*
  • Interleukin-23
  • Interleukin-23 Subunit p19
  • Interleukins / genetics
  • Interleukins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Pain Measurement / methods
  • RNA, Messenger / metabolism
  • Reaction Time / genetics
  • Reaction Time / physiology
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Sciatic Neuropathy / etiology
  • Sciatic Neuropathy / immunology
  • Sciatic Neuropathy / metabolism*
  • Sciatic Neuropathy / pathology
  • T-Lymphocytes / physiology*
  • Time Factors


  • CD3 Complex
  • Homeodomain Proteins
  • Il23a protein, mouse
  • Interleukin-15
  • Interleukin-17
  • Interleukin-23
  • Interleukin-23 Subunit p19
  • Interleukins
  • RNA, Messenger
  • RAG-1 protein