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. 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 molecul...

Dendritic cells were matured with TNF alpha, IFN gamma and PGE2. These DC were used to produce a DC vaccine.

These DC were matured using CpG-DNA as TLR9 ligand. Mature DCs upregulated CD80, CD86, MHC class II and produced cell type specific cytokines. Matured pDCs pDCs produced type 1 Interferons.

These DC were matured using CpG-DNA as TLR9 ligand. Mature DCs upregulated CD80, CD86, MHC class II and produced cell type specific cytokines. CD8+ myeloid DCs “cross-presented” exogeneous Ags (Ovalbumin).

We found that LPS-stimulated mDCs are able to induce up-regulation of co-stimulatory molecules on co-cultured pDCs. Likewise, CpG-stimulated pDCs activate co-cultured mDCs. The cross talk between these two populations of DC is very efficient since it can be observed at mDC/pDC ratio ranging from 1/10 to 10/1.

We are defining the differential roles of intestinal lymph DC subsets in activation of naïve and memory T cells. Two of the three DC subsets are highly potent activators of naïve CD4+ T cells, and do not appear to be constitutively suppressed in any way.

Indium labelled E/L-S DC (without antigen loading) is administered i.v. to a patient to study the reaction with regard to DC migration.

These cells do not acquire a mature phenotype and do not lead to an enhanced secretion of several cytokines/chemokines.

These cells 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.

These DC were generated by culturing enriched monocytes for 5 days.

These DC were used in a maturation step for subsequent production of a DC vaccine.

These DC were used to elicit CTL responses in a mouse model.

We are currently performing gene silencing experiments in human monocyte-derived DCs (MDDCs) with the dual aim of generating relevant knowledge on (i) the transcriptional regulation of DC differentiation, and (ii) the safe and rationale in vitro manipulation of gene expression in DCs.

We wanted to assess whether functional activation of human monocyte-derived DCs can be achieved by electroporation of an activation signal in the form of double-stranded (ds) RNA and whether simultaneous electroporation of the dsRNA with tumor antigen encoding mRNA can lead to the induction of a cytotoxic T-lymphocyte (CTL) response.

We performed co-cultures of IFN-DCs with zoledronate-stimulated gamma delta T lymphocytes. Gamma delta T-cell activation, as demonstrated by their up-modulation of activation marker expression levels (e.g. CD25 and CD69), was observed. The studies demonstrated for the first time the existence of a bidirectional activating interaction between DCs and gamma delta T lymphocytes activated by aminobiphosphonates.

We identified a novel DC subset called IKDC producing IFNg and expressing TRAIL which can recognize and kill transformed tumor cells in vitro and in vivo. Cultures were generated of tumor cells with IKDC producing IFNg and expressing TRAIL which can recognize and kill transformed tumor cells in vitro and in vivo. IKDC generate long contacts and synapses with tumor cells and ultimately kill them within 4 hours.

These dendritic cells were generated with interferon-beta and interleukin-3. They were used in a clinical trial in melanoma patients who were randomized to receive immunizations either with these I3 DC or with G4 DC (DC generated with GM-CSF and IL-4).

These DC were exposed to different maturation cocktails and various activators or inhibitors and profiled.

We have efficiently transfected DC with RNA encoding a functional protein (E/L-Selectin) which allows entry of DC into LN from HEV. The novel adherence capacity of human E/L-S transfected DC was demonstrated via sticking to sialyl-LewisX coated slides using a parallel plate flow microscope. RNA transfected human DC could be frozen and thawed without loosing their functionality.

Human DC exposed to TLR ligands and activated iNKT cells in vitro. They had enhanced expression of maturation markers, suggesting that a cooperative action of TLR ligands and iNKT cells on DC function is a generalizable phenomenon across species. These studies highlight the potential for manipulating the interactions between TLR ligands and iNKT cell activation in the design of effective vaccine adjuvants.