Human Langerhans cells use an IL-15R-α/IL-15/pSTAT5-dependent mechanism to break T-cell tolerance against the self-differentiation tumor antigen WT1 Academic Article uri icon


MeSH Major

  • Antigen Presentation
  • Immune Tolerance
  • Interleukin-15
  • Langerhans Cells
  • Receptors, Interleukin-15
  • STAT5 Transcription Factor
  • T-Lymphocytes, Cytotoxic
  • WT1 Proteins


  • Human CD34(+) progenitor-derived Langerhans-type dendritic cells (LCs) are more potent stimulators of T-cell immunity against tumor and viral antigens in vitro than are monocyte-derived DCs (moDCs). The exact mechanisms have remained elusive until now, however. LCs synthesize the highest amounts of IL-15R-α mRNA and protein, which binds IL-15 for presentation to responder lymphocytes, thereby signaling the phosphorylation of signal transducer and activator of transcription 5 (pSTAT5). LCs electroporated with Wilms tumor 1 (WT1) mRNA achieve sufficiently sustained presentation of antigenic peptides, which together with IL-15R-α/IL-15, break tolerance against WT1 by stimulating robust autologous, WT1-specific cytolytic T-lymphocytes (CTLs). These CTLs develop from healthy persons after only 7 days' stimulation without exogenous cytokines and lyse MHC-restricted tumor targets, which include primary WT1(+) leukemic blasts. In contrast, moDCs require exogenous rhuIL-15 to phosphorylate STAT5 and attain stimulatory capacity comparable to LCs. LCs therefore provide a more potent costimulatory cytokine milieu for T-cell activation than do moDCs, thus accounting for their superior stimulation of MHC-restricted Ag-specific CTLs without need for exogenous cytokines. These data support the use of mRNA-electroporated LCs, or moDCs supplemented with exogenous rhuIL-15, as vaccines for cancer immunotherapy to break tolerance against self-differentiation antigens shared by tumors.

publication date

  • June 5, 2012



  • Academic Article



  • eng

PubMed Central ID

  • PMC3369609

Digital Object Identifier (DOI)

  • 10.1182/blood-2011-09-382200

PubMed ID

  • 22510877

Additional Document Info

start page

  • 5182

end page

  • 90


  • 119


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