Neither IL-17A mRNA nor IL-17A protein are detectable in Langerhans cell histiocytosis lesions

Mol Ther. 2011 Aug;19(8):1433-9. doi: 10.1038/mt.2011.106. Epub 2011 Jun 7.


Langerhans cell histiocytosis (LCH) is a rare disease characterized by heterogeneous lesions including CD207(+)/CD1a(+) dendritic cells that can result in significant morbidity and mortality. The etiology of LCH remains speculative, and neoplastic and inflammatory origins have been debated for decades. A recent study identified abundant interleukin-17 (IL-17A) protein in dendritic cells in LCH lesions as well as in plasma from patients with active disease. Furthermore, it identified dendritic cells as a novel source of IL-17A expression. However, subsequent studies from our research group failed to identify any IL-17A gene expression from CD207(+) dendritic cells or CD3(+) T cells in LCH lesions. In this study, further investigation once again fails to identify any cells in LCH lesions with IL-17A gene expression. Furthermore, IL-17A antigen is undetectable in LCH lesion lysates with western blotting, immunoprecipitation, spectral analysis, and enzyme-linked immunosorbent assay (ELISA). Western blots, immunoprecipitation, and ELISA experiments also demonstrate that antibodies used in original studies that established the IL-17A hypothesis for pathogenesis of LCH recognize nonspecific proteins. We conclude that evidence for IL-17A as a significant factor in LCH remains inadequate and clinical trials targeting IL-17A remain unjustified.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • Antigens, CD / immunology
  • Antigens, CD1 / immunology
  • Blotting, Western
  • Dendritic Cells / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Histiocytosis, Langerhans-Cell / genetics
  • Histiocytosis, Langerhans-Cell / immunology*
  • Histiocytosis, Langerhans-Cell / pathology
  • Humans
  • Immunoprecipitation
  • Interleukin-17 / genetics
  • Interleukin-17 / metabolism*
  • Lectins, C-Type / immunology
  • Mannose-Binding Lectins / immunology
  • RNA, Messenger / analysis*
  • Reverse Transcriptase Polymerase Chain Reaction


  • Antibodies, Monoclonal
  • Antigens, CD
  • Antigens, CD1
  • CD1a antigen
  • CD207 protein, human
  • Interleukin-17
  • Lectins, C-Type
  • Mannose-Binding Lectins
  • RNA, Messenger