Enhancing the T-cell stimulatory capacity of human dendritic cells by co-electroporation with CD40L, CD70 and constitutively active TLR4 encoding mRNA

Mol Ther. 2008 Jun;16(6):1170-80. doi: 10.1038/mt.2008.77. Epub 2008 Apr 22.


The effectiveness of the dendritic cell (DC) vaccination protocols that are currently in use could be improved by providing the DCs with a more potent maturation signal. We therefore investigated whether the T-cell stimulatory capacity of human monocyte-derived DCs could be increased by co-electroporation with different combinations of CD40L, CD70, and constitutively active toll-like receptor 4 (caTLR4) encoding mRNA. We show that immature DCs electroporated with CD40L and/or caTLR4 mRNA, but not those electroporated with CD70 mRNA, acquire a mature phenotype along with an enhanced secretion of several cytokines/chemokines. Moreover, these DCs are very potent in inducing naive CD4(+) T cells to differentiate into interferon-gamma (IFN-gamma)-secreting type 1 T helper (Th1) cells. Further, we assessed the capacity of the electroporated DCs to activate naive HLA-A2-restricted MelanA-specific CD8(+) T cells without the addition of any exogenous cytokines. When all three molecules were combined, a >500-fold increase in MelanA-specific CD8(+) T cells was observed when compared with immature DCs, and a >200-fold increase when compared with cytokine cocktail-matured DCs. In correlation, we found a marked increase in cytolytic and IFN-gamma/tumor necrosis factor-alpha (TNF-alpha) secreting CD8(+) T cells. Our data indicate that immature DCs genetically modified to express stimulating molecules can induce tumor antigen-specific T cells in vitro and could prove to be a significant improvement over DCs matured with the methods currently in use.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD27 Ligand / metabolism*
  • CD40 Ligand / metabolism*
  • CD8-Positive T-Lymphocytes / metabolism
  • Cell Differentiation
  • Dendritic Cells / cytology*
  • Electroporation / methods*
  • HLA-A2 Antigen / metabolism
  • Humans
  • Interferon-gamma / metabolism
  • K562 Cells
  • Models, Biological
  • T-Lymphocytes / cytology*
  • Th1 Cells / cytology
  • Toll-Like Receptor 4 / metabolism*
  • Tumor Necrosis Factor-alpha / metabolism


  • CD27 Ligand
  • HLA-A2 Antigen
  • TLR4 protein, human
  • Toll-Like Receptor 4
  • Tumor Necrosis Factor-alpha
  • CD40 Ligand
  • Interferon-gamma