dsRNA-mediated innate immunity of epidermal keratinocytes

Biochem Biophys Res Commun. 2005 Sep 23;335(2):505-11. doi: 10.1016/j.bbrc.2005.07.105.

Abstract

MIP-1alpha, a CC chemokine, recruits monocytes, natural killer cells, lymphocytes, and neutrophils, and plays a critical role in viral infection. Since, the lesional epidermis of herpes zoster expressed MIP-1alpha, we hypothesized that keratinocytes produce MIP-1alpha in response to virus-associated dsRNA via TLR3. To investigate this, we examined cultured human keratinocytes for MIP-1alpha production induced by poly(I:C), a TLR3 ligand. Poly(I:C) treatment induced MIP-1alpha production, interestingly, poly(I:C)-induced IFN-alpha and -beta production preceded MIP-1alpha production. A neutralizing antibody for IFN-beta significantly inhibited the poly(I:C)-induced MIP-1alpha production indicating that MIP-1alpha production is via IFN-beta. IFN-alpha priming enhanced TLR3 expression and MIP-1alpha production in poly(I:C)-treated keratinocytes. This suggests that IFN-alpha enhanced the TLR3 expression and reinforced the response of keratinocytes to poly(I:C), which resulted in an increase in MIP-1alpha production. In conclusion, normal human keratinocytes produce MIP-1alpha in response to dsRNA via TLR3, and this production is regulated by IFN-alpha/beta.

MeSH terms

  • Cells, Cultured / cytology
  • Chemokine CCL3
  • Chemokine CCL4
  • Enzyme-Linked Immunosorbent Assay
  • Epidermal Cells
  • Epidermis / metabolism*
  • Herpes Zoster / genetics
  • Humans
  • Immunity, Innate
  • Immunohistochemistry
  • Interferon-beta / metabolism
  • Keratinocytes / cytology*
  • Keratinocytes / metabolism
  • Ligands
  • Macrophage Inflammatory Proteins / metabolism
  • Membrane Glycoproteins / metabolism
  • Models, Biological
  • RNA / metabolism
  • RNA, Double-Stranded / chemistry*
  • Receptors, Cell Surface / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Skin / metabolism
  • Time Factors
  • Toll-Like Receptor 3
  • Toll-Like Receptors

Substances

  • Chemokine CCL3
  • Chemokine CCL4
  • Ligands
  • Macrophage Inflammatory Proteins
  • Membrane Glycoproteins
  • RNA, Double-Stranded
  • Receptors, Cell Surface
  • TLR3 protein, human
  • Toll-Like Receptor 3
  • Toll-Like Receptors
  • RNA
  • Interferon-beta