IL-17 receptor signaling influences virus-induced corneal inflammation

J Leukoc Biol. 2008 Feb;83(2):401-8. doi: 10.1189/jlb.0807571. Epub 2007 Nov 12.

Abstract

IL-17 has been associated with selected inflammatory and autoimmune diseases. We characterized the expression of this proinflammatory cytokine following HSV-1 corneal infection and investigated whether IL-17R signaling modulated the host response to the viral pathogen at early time-points postinfection. IL-17 was elevated in the murine cornea 24 h after high-dose virus infection and subsequently persisted at low levels during the first week. Immunofluorescent studies showed that the IL-17R was expressed by cultured mouse corneal fibroblasts. Exposure of corneal cells to IL-17 led to production of IL-6 and MIP-2 in vitro and in vivo, indicating that the IL-17R was functional. Mice lacking IL-17R displayed significantly reduced neutrophil infiltration and corneal opacity. However, this effect was transient, as corneal pathology and neutrophil influx resembled that of wild-type (WT) hosts 4 days postinfection. HSV-1 growth and clearance in IL-17R(-/-) hosts were similar to that of the WT controls. Infection of IFN-gamma gene knockout mice was associated with elevated IL-17 levels and accelerated corneal opacity, suggesting that IFN-gamma negatively regulated IL-17 expression. Collectively, our results establish that IL-17 is rapidly produced in the cornea after HSV-1 infection and is regulated at least in part by IFN-gamma. The absence of IL-17 signaling results in a transient decrease in the expression of proinflammatory mediators, neutrophil migration, and corneal pathology, but control of virus growth in the cornea and trigeminal ganglia is not compromised. Thus, IL-17 actively influences early virus-induced corneal inflammation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cells, Cultured / metabolism
  • Cells, Cultured / virology
  • Chemokines / biosynthesis
  • Chemokines / genetics
  • Chemotaxis, Leukocyte / drug effects
  • Cornea / metabolism
  • Cornea / pathology
  • Cornea / virology
  • Female
  • Fibroblasts / metabolism
  • Fibroblasts / virology
  • Herpesvirus 1, Human*
  • Interferon-gamma / deficiency
  • Interferon-gamma / genetics
  • Interferon-gamma / physiology
  • Interleukin-17 / biosynthesis
  • Interleukin-17 / pharmacology
  • Interleukin-17 / physiology*
  • Interleukin-1alpha / pharmacology
  • Interleukin-6 / biosynthesis
  • Interleukin-6 / genetics
  • Keratitis, Herpetic / physiopathology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neutrophils / pathology
  • Receptors, Interleukin-17 / deficiency
  • Receptors, Interleukin-17 / genetics
  • Receptors, Interleukin-17 / physiology*
  • Specific Pathogen-Free Organisms
  • Up-Regulation / drug effects

Substances

  • Chemokines
  • Il17ra protein, mouse
  • Interleukin-17
  • Interleukin-1alpha
  • Interleukin-6
  • Receptors, Interleukin-17
  • Interferon-gamma