Differential development of plasmacytoid dendritic cells in Th1- and Th2-like cytokine milieus

Allergy. 2011 Mar;66(3):386-95. doi: 10.1111/j.1398-9995.2010.02497.x. Epub 2010 Oct 29.

Abstract

Background: Plasmacytoid dendritic cells (pDCs) infiltrate sites of Th1- and Th2-dominant inflammation and many studies have been performed to analyse their role in these immune responses. In contrast, much less is known about the effects of a Th1 or Th2 cytokine milieu on pDC function. Therefore, we investigated the impact of Th1- and Th2-like conditions during the development of pDCs on their antigen expression and function.

Methods: PDCs were matured in vitro by the addition of IL-3 under Th1- or Th2-like conditions. Antigen expression and TLR7-ligand-induced cytokine secretion was analysed by flow cytometry and ELISA. Furthermore, the CD4(+) T-cell polarizing capacity of pDCs was determined as well as their potential to induce CD4(+) T-cell proliferation.

Results: PDCs matured under Th1-like conditions showed a higher expression of antigens involved in T-cell co-stimulation and antigen presentation like CD40, CD80, CD83 and HLA-DR as well as a higher secretion of IL-6 and IFN-α in response to TLR7-ligation compared to Th2-pDCs. Furthermore, Th1-pDCs induced a significantly higher CD4(+) T-cell proliferation and primed a higher percentage of CD4(+) T cells to express IFN-γ and IL-2 after TLR7-ligation compared to Th2-pDCs. In contrast, Th2-pDCs were characterized by a significant upregulation of BDCA-3 and IL-4 expression following TLR7-ligation.

Conclusion: This study is the first to demonstrate the crucial impact of a surrounding cytokine environment on the development of pDC function including antigen expression. Based on these findings, it can be speculated that antiviral/bacterial pDC functions could be impaired during acute allergic conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD4-Positive T-Lymphocytes / metabolism
  • Cell Differentiation* / drug effects
  • Cell Proliferation / drug effects
  • Cytokines / pharmacology*
  • Dendritic Cells / cytology*
  • Dendritic Cells / drug effects
  • Dendritic Cells / metabolism*
  • Gene Expression Regulation, Developmental / drug effects
  • Humans
  • Th1 Cells / metabolism*
  • Th2 Cells / metabolism*
  • Toll-Like Receptor 7 / metabolism

Substances

  • Cytokines
  • Toll-Like Receptor 7