Plasmocytoid dendritic cell deficit of early response to toll-like receptor 7 agonist stimulation in multiple sclerosis patients

Clin Immunol. 2014 Jul;153(1):211-9. doi: 10.1016/j.clim.2014.04.016. Epub 2014 May 9.

Abstract

Plasmacytoid dendritic cells (pDCs), an important immunoregulatory population, are characterized by vigorous secretion of type I interferons (IFNs) in response to toll-like receptor (TLR) 7 and 9 stimulation. We studied the function of pDCs in multiple sclerosis (MS) patients by analysis of TLR7 responses. We assessed a pDC secretion pattern of cytokines in the short term PBMC cultures stimulated with TLR7 agonist. pDCs sorted from PBMCs of both MS patients and controls were used to assess TLR7 expression profile. TLR7 induced signaling in pDCs has been analyzed with intracellular flow cytometry. We have identified a clinically correlated significant decrease of the TLR7-induced IFN-alfa (IFNa) secretion by pDCs from MS patients. This deficit has been accompanied by insufficient intracellular phosphorylation of protein kinase Akt and a decrease of the TLR7 gene expression in MS pDCs. Our results demonstrated a selective pDC deficit in MS supporting a relationship between pDCs and mechanisms of MS.

Keywords: Autoimmunity; Immunoregulation; Multiple sclerosis; Plasmocytoid dendritic cells; Toll-like receptor; Type I interferon.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Case-Control Studies
  • Dendritic Cells / drug effects*
  • Dendritic Cells / immunology*
  • Enzyme Activation
  • Female
  • Humans
  • Interferon-alpha / biosynthesis
  • Intracellular Space / metabolism
  • Male
  • Middle Aged
  • Multiple Sclerosis / drug therapy
  • Multiple Sclerosis / genetics
  • Multiple Sclerosis / immunology*
  • Multiple Sclerosis / metabolism
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction
  • Toll-Like Receptor 7 / agonists*
  • Toll-Like Receptor 7 / genetics
  • Toll-Like Receptor 7 / metabolism
  • Transcription, Genetic

Substances

  • Interferon-alpha
  • Toll-Like Receptor 7
  • Proto-Oncogene Proteins c-akt