Detection of IL-17A-producing peripheral blood monocytes in Langerhans cell histiocytosis patients

Clin Immunol. 2014 Jul;153(1):112-22. doi: 10.1016/j.clim.2014.04.004. Epub 2014 Apr 15.


Langerhans cell histiocytosis (LCH) is a rare disease of unknown cause with manifestations ranging from isolated granulomatous lesions to life-threatening multi-system organ involvement. This disorder is further characterized by infiltration of immune cells in affected tissues and an association with interleukin (IL)-17A has been reported. Here, we investigated the presence of IL-17A-producing cells among peripheral blood mononuclear cells isolated from LCH patients and observed a high percentage of IL-17A(+) monocytes in peripheral blood of LCH patients compared to controls. The IL-17A(+) monocytes were also positive for the transcription factor retinoic acid orphan receptor (ROR) γt and showed increased mRNA levels for both IL-17A and RORγt. Notably, IL-17A was produced by all monocyte subsets and the expression level was positively associated with LCH disease activity. These data support a role for monocytes in the pathogenesis of LCH. Future therapeutic approaches may consider identification of patients who may benefit from IL-17A-targeted interventions.

Keywords: Interleukin-17A;; Langerhans cell histiocytosis;; Monocytes;; Retinoic acid orphan receptor C; Retinoic acid orphan receptor γt;.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Female
  • Gene Expression
  • Histiocytosis, Langerhans-Cell / genetics
  • Histiocytosis, Langerhans-Cell / immunology*
  • Histiocytosis, Langerhans-Cell / metabolism*
  • Humans
  • Immunophenotyping
  • Infant
  • Interleukin-17 / biosynthesis*
  • Interleukin-17 / genetics
  • Leukocyte Count
  • Lipopolysaccharide Receptors / metabolism
  • Male
  • Monocytes / immunology
  • Monocytes / metabolism*
  • Nuclear Receptor Subfamily 1, Group F, Member 3 / genetics
  • Nuclear Receptor Subfamily 1, Group F, Member 3 / metabolism
  • Transcription, Genetic
  • Young Adult


  • Interleukin-17
  • Lipopolysaccharide Receptors
  • Nuclear Receptor Subfamily 1, Group F, Member 3