The question was addressed of whether bLf, whose immunomodulant properties are now recognized, could influence MDDC differentiation/activation.

We investigated the interactions between human monocyte derived DCs (MDDC), generated in the presence of GM-CSF and IL-4 (IL-4 DC), and antigen-stimulated circulating gamma delta T lymphocytes, bearing the Vgamma2 TCR.

These monocyte-derived DCs received combined stimulation with TLR ligands. They were used in our study on DC activation by pathogen-derived stimuli.

These DC are exposed to HIV-1 to examine if this can directly modulate their functions or interfere with their cross-talk.

We have electroporated these DC with melanoma antigen RNA for a cross-presentation study and showed that they express the proteins ex vivo and in vivo.

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.

We have studied the immuno-physiology of rat and mouse intestinal dendritic cells. We have used a known adjuvant, E. coli heat-labile toxin (Etx) and a potential adjuvant R-848, a small TLR7/8 ligand.

The DC were matured with TLR ligand R848 and polyI:C. Using these DC, we obtained best results in our evaluation whether antigens could be rerouted from the endosomal into the cytosolic compartment by combining antigen with cell penetrating peptides to further enhance cross-presentation.

Using pharmacological inhibitors, or macrophages and DC from mice carrying a null mutation in MAP kinase signalling molecule(s), we have evidence for a role of certain MAP kinases in the regulation of IL-10 and IL-12, IFN-gamma production.

Since LPS-activated DC are potent inducers of NK cell priming and lymph nodes appear to be a key place in which DC and NK cell interactions occur, we have investigated the in vivo capacity of resting and DC-primed NK cells to reach the draining lymph nodes.

We have efficiently transfected DC with RNA encoding a functional protein (E/L-selectin), which allows entry of DC into LN from HEV. These DC rolled in vitro on sialyl-LewisX-coated slides, and in vivo, mouse E/L-selectin-transfected DC homed to LN after i.v. application.

We used dendritic cells loaded with anti-DEC205-antigen constructs, consisting of a single-chain variable fragment (scFv) directed against DEC-205, genetically linked to different parts of the MAGE-A3 model antigen (i.e. the KKl and EVDPIGHLY peptides), in a study to compare antigen-loading strategies.

For a transcriptional profiling of dendritic cells, DC were stimulated with PolyI:C, pretreated or not with PP2, and microarray analysis was performed.

These multipeptide loaded cytokine matured moDC +/- CD40L activation were used for the DERMA-ER-DC 04 trial.

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.