title: Enhancing the T-cell stimulatory capacity of human dendritic cells by co-electroporation with CD40L, CD70 and constitutively active TLR4 encoding mRNA.
abstract: 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.
authors.affiliation: Laboratory of Molecular and Cellular Therapy, Department of Physiology-Immunology, Medical School of the Vrije Universiteit Brussel, Brussels, Belgium. aude.bonehill@vub.ac.be
authors.forename: Aude
authors.initials: A
authors.lastname: Bonehill
authors.forename: Sandra
authors.initials: S
authors.lastname: Tuyaerts
authors.forename: An M T
authors.initials: AM
authors.lastname: Van Nuffel
authors.forename: Carlo
authors.initials: C
authors.lastname: Heirman
authors.forename: Tomas J
authors.initials: TJ
authors.lastname: Bos
authors.forename: Karel
authors.initials: K
authors.lastname: Fostier
authors.forename: Bart
authors.initials: B
authors.lastname: Neyns
authors.forename: Kris
authors.initials: K
authors.lastname: Thielemans
mesh_terms: D053282:CD27 Ligand / Q000378:metabolism*; D023201:CD40 Ligand / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D002454:Cell Differentiation; D003713:Dendritic Cells / Q000166:cytology*; D018274:Electroporation / Q000379:methods*; D015789:HLA-A2 Antigen / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D020014:K562 Cells; D008954:Models, Biological; D013601:T-Lymphocytes / Q000166:cytology*; D018417:Th1 Cells / Q000166:cytology; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D053282:CD27 Ligand; D015789:HLA-A2 Antigen; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D023201:CD40 Ligand; D007371:Interferon-gamma